U.S. patent application number 13/117928 was filed with the patent office on 2011-09-22 for apparatus for processing substrate and method of doing the same.
This patent application is currently assigned to NEC CORPORATION. Invention is credited to Shusaku KIDO.
Application Number | 20110229831 13/117928 |
Document ID | / |
Family ID | 38748440 |
Filed Date | 2011-09-22 |
United States Patent
Application |
20110229831 |
Kind Code |
A1 |
KIDO; Shusaku |
September 22, 2011 |
APPARATUS FOR PROCESSING SUBSTRATE AND METHOD OF DOING THE SAME
Abstract
An apparatus for processing a substrate includes a
gas-atmosphere applying unit for applying gas atmosphere to the
substrate, and a light-exposure unit for exposing the substrate to
light through a lower surface of the substrate.
Inventors: |
KIDO; Shusaku; (Kanagawa,
JP) |
Assignee: |
NEC CORPORATION
Tokyo
JP
|
Family ID: |
38748440 |
Appl. No.: |
13/117928 |
Filed: |
May 27, 2011 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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11754827 |
May 29, 2007 |
|
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13117928 |
|
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Current U.S.
Class: |
430/325 ;
118/704; 252/79.1; 427/162; 427/271; 427/535; 427/553; 427/58;
427/66; 427/98.4 |
Current CPC
Class: |
H01L 27/1288 20130101;
H01L 29/66765 20130101; G03F 7/2022 20130101; H01L 21/67225
20130101; H01L 21/0273 20130101; G03F 7/40 20130101 |
Class at
Publication: |
430/325 ;
118/704; 427/271; 427/98.4; 427/535; 427/553; 427/66; 427/58;
427/162; 252/79.1 |
International
Class: |
G03F 7/20 20060101
G03F007/20; B05C 11/00 20060101 B05C011/00; B05C 9/12 20060101
B05C009/12; B05C 13/00 20060101 B05C013/00; B05D 5/00 20060101
B05D005/00; B05D 3/04 20060101 B05D003/04; B05D 3/06 20060101
B05D003/06; B05D 3/10 20060101 B05D003/10; B05D 1/00 20060101
B05D001/00; C09K 13/00 20060101 C09K013/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 29, 2006 |
JP |
2006-147810 |
Claims
1. An apparatus for processing a substrate, comprising: a substrate
carrier for carrying said substrate; a gas-atmosphere applying unit
for applying gas atmosphere to said substrate; a third processing
unit for applying a third removal step to said substrate; and a
controller for controlling said substrate carrier, said
gas-atmosphere applying unit and said third processing unit such
that a step of applying gas atmosphere to said substrate, to be
carried out by said gas-atmosphere applying unit, and said third
removal step to be carried out by said third processing unit are
carried out in this order.
2. The apparatus as set forth in claim 1, further comprising a
substrate-temperature controlling unit for controlling a
temperature of said substrate, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit and said third processing
unit such that a step of controlling a temperature of said
substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
and said third removal step to be carried out by said third
processing unit are carried out in this order.
3. The apparatus as set forth in claim 2, further comprising a
substrate-heating unit for heating said substrate, and wherein said
controller controls said substrate carrier, said
substrate-temperature controlling unit, said gas-atmosphere
applying unit, said substrate-heating unit and said third
processing unit such that a step of controlling a temperature of
said substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
a step of heating said substrate, to be carried out by said
substrate-heating unit, and said third removal step to be carried
out by said third processing unit are carried out in this
order.
4. The apparatus as set forth in claim 3, further comprising a
second substrate-temperature controlling unit for controlling a
temperature of said substrate after said substrate was heated by
said substrate-heating unit, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit, said substrate-heating
unit, said third processing unit, and said second
substrate-temperature controlling unit such that a step of
controlling a temperature of said substrate, to be carried out by
said substrate-temperature controlling unit, a step of applying gas
atmosphere to said substrate, to be carried out by said
gas-atmosphere applying unit, a step of heating said substrate, to
be carried out by said substrate-heating unit, said third removal
step to be carried out by said third processing unit, and a step of
controlling a temperature of said substrate, to be carried out by
said second substrate-temperature controlling unit are carried out
in this order.
5. The apparatus as set forth in claim 4, further comprising a
second substrate-heating unit for heating said substrate after said
third removal step was applied to said substrate by said third
processing unit, and wherein said controller controls said
substrate carrier, said substrate-temperature controlling unit,
said gas-atmosphere applying unit, said substrate-heating unit,
said third processing unit, said second substrate-temperature
controlling unit, and said second substrate-heating unit such that
a step of controlling a temperature of said substrate, to be
carried out by said substrate-temperature controlling unit, a step
of applying gas atmosphere to said substrate, to be carried out by
said gas-atmosphere applying unit, a step of heating said
substrate, to be carried out by said substrate-heating unit, said
third removal step to be carried out by said third processing unit,
a step of controlling a temperature of said substrate, to be
carried out by said second substrate-temperature controlling unit,
and a step of heating said substrate, to be carried out by said
second substrate-heating unit are carried out in this order.
6. The apparatus as set forth in claim 1, further comprising a
first removal processing unit for applying a first removal step to
said substrate.
7. The apparatus as set forth in claim 6, further comprising a
substrate-temperature controlling unit for controlling a
temperature of said substrate, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit, and said third processing
unit such that a step of controlling a temperature of said
substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
and said third removal step to be carried out by said third
processing unit are carried out in this order.
8. The apparatus as set forth in claim 7, further comprising a
substrate-heating unit for heating said substrate, and wherein said
controller controls said substrate carrier, said
substrate-temperature controlling unit, said gas-atmosphere
applying unit, said substrate-heating unit, and said third
processing unit such that a step of controlling a temperature of
said substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
a step of heating said substrate, to be carried out by said
substrate-heating unit, and said third removal step to be carried
out by said third processing unit are carried out in this
order.
9. The apparatus as set forth in claim 8, further comprising a
second substrate-temperature controlling unit for controlling a
temperature of said substrate after said substrate was heated by
said substrate-heating unit, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit, said substrate-heating
unit, said third processing unit, and said second
substrate-temperature controlling unit such that a step of
controlling a temperature of said substrate, to be carried out by
said substrate-temperature controlling unit, a step of applying gas
atmosphere to said substrate, to be carried out by said
gas-atmosphere applying unit, a step of heating said substrate, to
be carried out by said substrate-heating unit, said third removal
step to be carried out by said third processing unit, and a step of
controlling a temperature of said substrate, to be carried out by
said second substrate-temperature controlling unit are carried out
in this order.
10. The apparatus as set forth in claim 9, further comprising a
second substrate-heating unit for heating said substrate after said
third removal step was applied to said substrate by said third
processing unit, and wherein said controller controls said
substrate carrier, said substrate-temperature controlling unit,
said gas-atmosphere applying unit, said substrate-heating unit,
said third processing unit, said second substrate-temperature
controlling unit, and said second substrate-heating unit such that
a step of controlling a temperature of said substrate, to be
carried out by said substrate-temperature controlling unit, a step
of applying gas atmosphere to said substrate, to be carried out by
said gas-atmosphere applying unit, a step of heating said
substrate, to be carried out by said substrate-heating unit, said
third removal step to be carried out by said third processing unit,
a step of controlling a temperature of said substrate, to be
carried out by said second substrate-temperature controlling unit,
and a step of heating said substrate, to be carried out by said
second substrate-heating unit are carried out in this order.
11. The apparatus as set forth in claim 6, further comprising a
second processing unit for applying a second removal step to said
substrate.
12. The apparatus as set forth in claim 11, further comprising a
substrate-temperature controlling unit for controlling a
temperature of said substrate, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit, and said third processing
unit such that a step of controlling a temperature of said
substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
and said third removal step to be carried out by said third
processing unit are carried out in this order.
13. The apparatus as set forth in claim 12, further comprising a
substrate-heating unit for heating said substrate, and wherein said
controller controls said substrate carrier, said
substrate-temperature controlling unit, said gas-atmosphere
applying unit, said substrate-heating unit, and said third
processing unit such that a step of controlling a temperature of
said substrate, to be carried out by said substrate-temperature
controlling unit, a step of applying gas atmosphere to said
substrate, to be carried out by said gas-atmosphere applying unit,
a step of heating said substrate, to be carried out by said
substrate-heating unit, and said third removal step to be carried
out by said third processing unit are carried out in this
order.
14. The apparatus as set forth in claim 13, further comprising a
second substrate-temperature controlling unit for controlling a
temperature of said substrate after said substrate was heated by
said substrate-heating unit, and wherein said controller controls
said substrate carrier, said substrate-temperature controlling
unit, said gas-atmosphere applying unit, said substrate-heating
unit, said third processing unit, and said second
substrate-temperature controlling unit such that a step of
controlling a temperature of said substrate, to be carried out by
said substrate-temperature controlling unit, a step of applying gas
atmosphere to said substrate, to be carried out by said
gas-atmosphere applying unit, a step of heating said substrate, to
be carried out by said substrate-heating unit, said third removal
step to be carried out by said third processing unit, and a step of
controlling a temperature of said substrate, to be carried out by
said second substrate-temperature controlling unit are carried out
in this order.
15. The apparatus as set forth in claim 14, further comprising a
second substrate-heating unit for heating said substrate after said
third removal step was applied to said substrate by said third
processing unit, and wherein said controller controls said
substrate carrier, said substrate-temperature controlling unit,
said gas-atmosphere applying unit, said substrate-heating unit,
said third processing unit, said second substrate-temperature
controlling unit, and said second substrate-heating unit such that
a step of controlling a temperature of said substrate, to be
carried out by said substrate-temperature controlling unit, a step
of applying gas atmosphere to said substrate, to be carried out by
said gas-atmosphere applying unit, a step of heating said
substrate, to be carried out by said substrate-heating unit, said
third removal step to be carried out by said third processing unit,
a step of controlling a temperature of said substrate, to be
carried out by said second substrate-temperature controlling unit,
and a step of heating said substrate, to be carried out by said
second substrate-heating unit are carried out in this order.
16. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of a first chemical-solution applying
unit for applying chemical solution to said substrate.
17. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of an ashing unit for applying an
ashing step to said substrate.
18. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of a first chemical-solution applying
unit for applying first chemical solution to said substrate, and a
second chemical-solution applying unit for applying second chemical
solution to said substrate, and wherein said controller controls
said first and second chemical-solution applying units such that a
step of applying said first chemical solution to said substrate and
a step of applying second chemical solution to said substrate are
carried out in this order.
19. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of a chemical-solution applying unit
for applying first chemical solution to said substrate, and further
for applying second chemical solution to said substrate, and
wherein said controller controls said chemical-solution applying
unit such that a step of applying said first chemical solution to
said substrate and a step of applying second chemical solution to
said substrate are carried out in this order.
20. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of an ashing unit for applying an
ashing step to said substrate, and a second chemical-solution
applying unit for applying second chemical solution to said
substrate, and wherein said controller controls said ashing unit
and said second chemical-solution applying unit such that said
ashing step and a step of applying said second chemical solution to
said substrate are carried out in this order.
21. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of an
ashing/chemical-solution-applying unit for applying an ashing step
to said substrate, and further for applying second chemical
solution to said substrate, and wherein said controller controls
said ashing/chemical-solution-applying unit such that said ashing
step and a step of applying said second chemical solution to said
substrate are carried out in this order.
22. The apparatus as set forth in claim 11, wherein at least one of
said first and second removal steps comprises a step of developing
an organic film pattern formed on said substrate through the use of
chemical solution having a function of developing said organic film
pattern, and wherein at least one of said first and second
processing units is comprised of a developing unit for developing
said organic film pattern.
23. The apparatus as set forth in claim 1, wherein said third
processing unit is comprised of a unit for applying a chemical
solution to an organic film pattern formed on said substrate.
24. The apparatus as set forth in claim 6, wherein said first
processing unit is comprised of a unit for applying a chemical
solution to an organic film pattern formed on said substrate.
25. The apparatus as set forth in claim 11, wherein said second
processing unit is comprised of a unit for applying a chemical
solution to an organic film pattern formed on said substrate.
26. The apparatus as set forth in claim 22, wherein said developing
unit develops an organic film pattern formed on said substrate.
27. The apparatus as set forth in claim 23, wherein said third
processing unit uses a chemical solution containing at least one of
acid chemical, organic solvent, and alkaline chemical.
28. The apparatus as set forth in claim 24, wherein said first
processing unit uses a chemical solution containing at least one of
acid chemical, organic solvent, and alkaline chemical.
29. The apparatus as set forth in claim 25, wherein said second
processing unit uses a chemical solution containing at least one of
acid chemical, organic solvent, and alkaline chemical.
30. The apparatus as set forth in claim 27, wherein said third
processing unit is comprised of a developing unit which carries
out, as said third removal step, a step of developing an organic
film pattern formed on said substrate through the use of a
developing agent.
31. The apparatus as set forth in claim 28, wherein said first
processing unit is comprised of a developing unit which carries
out, as said first removal step, a step of developing an organic
film pattern formed on said substrate through the use of a
developing agent.
32. The apparatus as set forth in claim 29, wherein said second
processing unit is comprised of a developing unit which carries
out, as said second removal step, a step of developing an organic
film pattern formed on said substrate through the use of a
developing agent.
33. The apparatus as set forth in claim 1, wherein an order in
which said units are operated is variable.
34. The apparatus as set forth in claim 1, wherein an order in
which said units are operated is fixed.
35. The apparatus as set forth in claim 1, wherein conditions in
accordance with which said units are operated are variable.
36. The apparatus as set forth in claim 1, wherein said apparatus
includes a plurality of common units.
37. The apparatus as set forth in claim 36, wherein substrates are
in different directions from one another in a plane defined by said
substrate during being processed in said common units.
38. The apparatus as set forth in claim 37, wherein substrates are
oppositely directed in a plane defined by said substrate during
being processed in said common units.
39. The apparatus as set forth in claim 1, wherein said substrate
is processed a plurality of times in at least one of said units
with said substrate being directed differently in a plane defined
by said substrate in each of times.
40. The apparatus as set forth in claim 1, wherein said substrate
is processed a plurality of times in at least one of said units
with said substrate being directed oppositely in a plane defined by
said substrate in each of times.
41. The apparatus as set forth in claim 1, wherein said substrate
is processed in at least one of said units in a first direction and
in a second direction different from said first direction.
42. The apparatus as set forth in claim 41, wherein said first and
second directions are opposite to each other.
43. The apparatus as set forth in claim 1, wherein said apparatus
has a function of prevent at least one of explosion and
inflammation thereof.
44. The apparatus as set forth in claim 1, wherein said
gas-applying unit has a function of prevent at least one of
explosion and inflammation thereof.
45. The apparatus as set forth in claim 1, further comprising an
etching unit for etching said substrate.
46. A method of processing an organic film pattern formed on a
substrate, comprising, in sequence of; a fusion/deformation step of
fusing and thereby deforming said organic film pattern; and a third
removal step of removing at least a part of the fused and deformed
organic film pattern.
47. The method as set forth in claim 46, further comprising a
second heating step of heating the fused and deformed organic film
pattern, said second heating step being carried out after said
fusion/deformation step and before said third removal step.
48. The method as set forth in claim 47, further comprising a third
heating step of heating the fused and deformed organic film
pattern, said third heating step being carried out after said third
removal step.
49. The method as set forth in claim 48, further comprising a first
heating step of heating said organic film pattern, said first
heating step being carried out before said fusion/deformation
step.
50. The method as set forth in claim 46, further comprising a first
removal step of removing at least one of an alterated layer and a
deposited layer formed on a surface of said organic film pattern,
said first removal step being carried out before said
fusion/deformation step.
51. The method as set forth in claim 50, further comprising a
second heating step of heating the fused and deformed organic film
pattern, said second heating step being carried out after said
fusion/deformation step and before said third removal step.
52. The method as set forth in claim 51, further comprising a third
heating step of heating the fused and deformed organic film
pattern, said third heating step being carried out after said third
removal step.
53. The method as set forth in claim 52, further comprising a first
heating step of heating said organic film pattern, said first
heating step being carried out before said first removal step.
54. The method as set forth in claim 46, further comprising a first
removal step of removing at least one of an alterated layer and a
deposited layer formed on a surface of said organic film pattern,
and a second removal step of removing a part of said organic film
pattern, said first removal step being carried out before said
fusion/deformation step, said second removal step being carried out
after said first removal step and before said fusion/deformation
step.
55. The method as set forth in claim 54, further comprising a
second heating step of heating the fused and deformed organic film
pattern, said second heating step being carried out after said
fusion/deformation step and before said third removal step.
56. The method as set forth in claim 55, further comprising a third
heating step of heating the fused and deformed organic film
pattern, said third heating step being carried out after said third
removal step.
57. The method as set forth in claim 56, further comprising a first
heating step of heating said organic film pattern, said first
heating step being carried out before said first removal step.
58. The method as set forth in claim 46, further comprising a
substrate-temperature controlling step of keeping constant a
temperature at which said substrate is processed, said
substrate-temperature controlling step being carried out
immediately before said fusion/deformation step.
59. The method as set forth in claim 46, further comprising
originally forming said organic film pattern on said substrate by
printing or by photolithography.
60. The method as set forth in claim 46, further comprising
originally forming a photosensitive organic film as said organic
film pattern on said substrate.
61. The method as set forth in claim 60, wherein said
photosensitive organic film is comprised of one of a positive type
photosensitive organic film and a negative type photosensitive
organic film.
62. The method as set forth in claim 61, wherein said positive type
photosensitive organic film contains novolak resin as a principal
constituent.
63. The method as set forth in claim 60, wherein said
photosensitive organic film is soluble in alkali, if exposed to
light.
64. The method as set forth in claim 54, wherein one of said
alterated layer and said deposited layer is selectively removed in
at least one of said first and second removal steps.
65. The method as set forth in claim 54, wherein one of said
alterated layer and said deposited layer is selectively removed,
and a non-alterated portion of said organic film pattern is caused
to appear in at least one of said first and second removal
steps.
66. The method as set forth in claim 54, wherein a non-alterated
portion of said organic film pattern is partially removed in at
least one of said first and second removal steps.
67. The method as set forth in claim 46, wherein one of an
alterated layer and a deposited layer formed on the fused and
deformed organic film pattern, or one of an alterated layer and a
deposited layer formed around the fused and deformed organic film
pattern is selectively removed in said third removal step.
68. The method as set forth in claim 46, wherein one of an
alterated layer and a deposited layer formed on the fused and
deformed organic film pattern, or one of an alterated layer and a
deposited layer formed around the fused and deformed organic film
pattern is selectively removed in said third removal step for
causing the fused and deformed organic film pattern to appear.
69. The method as set forth in claim 46, wherein one of an
alterated layer and a deposited layer formed on the fused and
deformed organic film pattern, or one of an alterated layer and a
deposited layer formed around the fused and deformed organic film
pattern is selectively removed in said third removal step, and the
fused and deformed organic film pattern is partially removed.
70. The method as set forth in claim 54, wherein at least a part of
at least one of said first, second and third removal steps is
comprised of a step of applying chemical solution to said organic
film pattern.
71. The method as set forth in claim 54, wherein at least a part of
at least one of said first, second and third removal steps is
comprised of a step of ashing said organic film pattern.
72. The method as set forth in claim 54, wherein at least a part of
at least one of said first, second and third removal steps is
comprised of a step of ashing said organic film pattern, and a step
of applying chemical solution to said organic film pattern.
73. The method as set forth in claim 46, wherein said third removal
step is comprised of a step of twice applying chemical solution to
said organic film pattern through the use of two different chemical
solutions.
74. The method as set forth in claim 49, wherein at least one of
water, acid and alkali having penetrated said organic film pattern
before said organic film pattern was processed is removed in at
least one of said first, second and third heating steps.
75. The method as set forth in claim 49, wherein, when an adhesive
force between said organic film pattern and said substrate or an
underlying film is lowered, at least one of said first, second and
third heating steps enhances said adhesive force.
76. The method as set forth in claim 46, wherein a heating step for
forming said organic film pattern is carried out at a temperature
equal to or smaller than a temperature at which said organic film
pattern is cross-linked.
77. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern and said first heating step are
carried out at a temperature equal to or smaller than a temperature
at which said organic film pattern is cross-linked.
78. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern, said first heating step, and
said second heating step are carried out at a temperature equal to
or smaller than a temperature at which said organic film pattern is
cross-linked.
79. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern, said first heating step, said
second heating step, and said third heating step are carried out at
a temperature equal to or smaller than a temperature at which said
organic film pattern is cross-linked.
80. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern, said first heating step, said
second heating step, and said third heating step are carried out at
a temperature in the range of 50 to 150 degrees centigrade both
inclusive.
81. The method as set forth in claim 80, wherein a heating step for
forming said organic film pattern, said first heating step, said
second heating step, and said third heating step are carried out at
a temperature in the range of 100 to 130 degrees centigrade both
inclusive.
82. The method as set forth in claim 49, wherein said first heating
step is carried out at a temperature lower than a temperature at
which said second heating step is carried out.
83. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern and said first heating step are
carried out at a temperature lower than a temperature at which said
second heating step is carried out.
84. The method as set forth in claim 49, wherein said second
heating step is carried out at a temperature lower than a
temperature at which said third heating step is carried out.
85. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern, said first heating step, and
said second heating step are carried out at a temperature lower
than a temperature at which said third heating step is carried
out.
86. The method as set forth in claim 49, wherein said first heating
step is carried out at a temperature lower than a temperature at
which said third heating step is carried out.
87. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern and said first heating step are
carried out at a temperature lower than a temperature at which said
third heating step is carried out.
88. The method as set forth in claim 49, wherein a heating step for
forming said organic film pattern, said first heating step, said
second heating step, and said third heating step are carried out
for 60 to 300 seconds both inclusive.
89. The method as set forth in claim 50, wherein said alterated
layer is comprised of a surface of said organic film pattern
alterated by at least one of aging, thermal oxidation, heat curing,
wet etching, dry etching, ashing, and deposition resulted from dry
etching.
90. The method as set forth in claim 50, wherein said deposited
layer formed on said organic film pattern is caused by
dry-etching.
91. The method as set forth in claim 46, wherein an area of said
organic film pattern is increased in said fusion/deformation
step
92. The method as set forth in claim 46, wherein organic film
patterns disposed adjacent to each other are joined in said
fusion/deformation step
93. The method as set forth in claim 46, wherein said organic film
pattern is planarized in said fusion/deformation step
94. The method as set forth in claim 46, wherein said organic film
pattern is deformed in said fusion/deformation step such that said
organic film pattern is turned into an electrically insulating film
covering therewith a circuit pattern formed on said substrate.
95. The method as set forth in claim 46, wherein said organic film
pattern is deformed in said fusion/deformation step by making
contact with organic solution to cause fusion reflow.
96. The method as set forth in claim 95, wherein said organic
solution contains at least one of the following organic solvents (R
indicates an alkyl group or a substitutional alkyl group, Ar
indicates a phenyl group or an aromatic ring other than a phenyl
group): (a) alcohol (R--OH); (b) ether (R--O--R, Ar--O--R,
Ar--O--Ar); (3) ester; (4) ketone; and (5) glycol ether.
97. The method as set forth in claim 95, wherein said organic film
pattern is exposed to vapor of said organic solvent in said fusion
reflow.
98. The method as set forth in claim 95, wherein said organic film
pattern is immersed into said organic solvent in said fusion
reflow.
99. The method as set forth in claim 95, wherein said fusion reflow
is comprised of a step of applying gas atmosphere to said organic
film pattern.
100. The method as set forth in claim 99, wherein said step of
applying gas atmosphere to said organic film patter is carried out
in gas atmosphere of said organic solvent.
101. The method as set forth in claim 54, wherein said first
removal step is comprised of a first chemical-solution step of
applying chemical solution to said organic film pattern.
102. The method as set forth in claim 54, wherein at least one of
said second and third removal steps is comprised of a second
chemical-solution step of applying chemical solution to said
organic film pattern.
103. The method as set forth in claim 54, wherein at least one of
said first, second and third removal steps is comprised of an
ashing step of ashing said organic film pattern.
104. The method as set forth in claim 54, wherein said first
removal step is comprised of, in sequence of, an ashing step of
ashing said organic film pattern, and a first chemical-solution
step of applying chemical solution to said organic film
pattern.
105. The method as set forth in claim 54, wherein at least one of
said second and third removal steps is comprised of, in sequence
of, an ashing step of ashing said organic film pattern, and a
second chemical-solution step of applying chemical solution to said
organic film pattern.
106. The method as set forth in claim 54, wherein said third
removal step is comprised of a first chemical-solution step of
applying chemical solution to said organic film pattern, and a
second chemical-solution step of applying chemical solution to said
organic film pattern.
107. The method as set forth in claim 54, wherein each of said
first, second and third removal steps is comprised of a step of
applying chemical solution to said organic film pattern.
108. The method as set forth in claim 103, wherein films formed on
said substrate are etched in said ashing step through the use of at
least one of plasma, ozone and ultraviolet rays.
109. The method as set forth in claim 54, further comprising a
light-exposure step of exposing said organic film pattern to light
before at least one of said first, second and third removal
steps.
110. The method as set forth in claim 101, further comprising a
light-exposure step of exposing said organic film pattern to light
immediately before at least one of said first and second
chemical-solution steps.
111. The method as set forth in claim 54, further comprising a back
light-exposure step of exposing said organic film pattern to light
through a lower surface of said substrate, said back light-exposure
step being carried out between said fusion/deformation step and
said third removal step or between said fusion/deformation step and
said second chemical-solution step.
112. The method as set forth in claim 111, wherein said organic
film pattern is exposed to light in said exposure step and said
back light-exposure step only in an area associated with a
predetermined area of said substrate.
113. The method as set forth in claim 112, wherein said organic
film pattern is exposed to light in said exposure step and said
back light-exposure step in an area associated with a predetermined
area of said substrate by radiating light entirely over said area
or by scanning said area with spot-light.
114. The method as set forth in claim 112, wherein said
predetermined area has an area equal to or greater than 1/10 of an
area of said substrate.
115. The method as set forth in claim 112, wherein said organic
film pattern is exposed to ultra-violet rays, fluorescence, or
natural light in said exposure step and said back light-exposure
step.
116. The method as set forth in claim 101, wherein at least one of
said first and second chemical-solution steps is comprised of a
developing step of developing said organic film pattern through the
use of chemical solution having a function of developing said
organic film pattern.
117. The method as set forth in claim 101, wherein at least one of
said first and second chemical-solution steps is comprised of an
overdeveloping step of carrying out N-th development of said
organic film pattern through the use of chemical solution having a
function of developing said organic film pattern, wherein N
indicates an integer equal to or greater than two.
118. The method as set forth in claim 101, wherein at least one of
said first and second chemical-solution steps is comprised of a
chemical-solution step of applying chemical solution to said
organic film pattern, said chemical solution not having a function
of developing said organic film pattern, but having a function of
fusing said organic film pattern.
119. The method as set forth in claim 118, wherein said chemical
solution is comprised of a solution obtained by diluting separating
agent.
120. The method as set forth in claim 116, wherein said chemical
solution having a function of developing said organic film pattern
is comprised of alkaline aqueous solution containing TMAH
(tetramethylammonium hydroxide) as a principal constituent, or
inorganic alkaline aqueous solution.
121. The method as set forth in claim 120, wherein said inorganic
alkaline aqueous solution is one of NaOH aqueous solution and CaOH
aqueous solution.
122. The method as set forth in claim 46, wherein said organic film
pattern formed originally on said substrate has at least two
portions having different thicknesses from one another.
123. The method as set forth in claim 46, wherein said organic film
pattern formed originally on said substrate has at least two
portions having different thicknesses from one another, and a
thinner portion among said portions of said organic film pattern is
further thinned in at least one of said first, second and third
removal steps.
124. The method as set forth in claim 46, wherein said organic film
pattern formed originally on said substrate has at least two
portions having different thicknesses from one another, and a
thinner portion among said portions of said organic film pattern is
removed in at least one of said first, second and third removal
steps.
125. The method as set forth in claim 46, wherein said organic film
pattern is kept not exposed to light until said fusion/deformation
step is carried out after said organic film pattern was originally
formed on said substrate.
126. The method as set forth in claim 112, wherein said organic
film pattern is kept not exposed to light until said light-exposure
step or back light-exposure step is carried out after said organic
film pattern was originally formed on said substrate.
127. The method as set forth in claim 46, further comprising a
patterning step of patterning an underlying film formed below said
organic film pattern, with said organic film pattern being used as
a mask, before said fusion/deformation step is applied to said
organic film pattern.
128. The method as set forth in claim 49, further comprising a
patterning step of patterning an underlying film formed below said
organic film pattern, with said organic film pattern being used as
a mask, before said fusion/deformation step, said first removal
step or said first heating step is applied to said organic film
pattern.
129. The method as set forth in claim 48, further comprising a
patterning step of patterning an underlying film formed below said
organic film pattern, with said organic film pattern being used as
a mask, after said second heating step, said third removal step or
said third heating step was applied to said organic film
pattern.
130. The method as set forth in claim 46, further comprising a
patterning step of patterning an underlying film formed below said
organic film pattern, with said organic film pattern being used as
a mask, before said fusion/deformation step is carried out or after
said third removal step was carried out.
131. The method as set forth in claim 127, wherein said underlying
film is patterned to be tapered or step-liked in said patterning
step.
132. The method as set forth in claim 127, wherein said underlying
film is comprised of a plurality of films, and some of said films
are patterned into different patterns from one another in said
patterning step.
133. The method as set forth in claim 101, wherein said chemical
solution used in said first chemical-solution step contains at
least one of acid chemical, organic solvent, alkaline chemical,
amine, organic solvent and amine, and alkaline chemical and
amine.
134. The method as set forth in claim 102, wherein said chemical
solution used in said first chemical-solution step contains at
least one of acid chemical, organic solvent, alkaline chemical,
amine, organic solvent and amine, and alkaline chemical and
amine.
135. The method as set forth in claim 134, wherein said organic
solvent contains at least amine.
136. The method as set forth in claim 134, wherein said alkaline
chemical contains at least amine and water.
137. The method as set forth in claim 134, wherein said amine is
selected from a group consisting of monoethyl amine, diethyl amine,
triethyl amine, monoisopyl amine, diisopyl amine, triisoply amine,
monobutyl amine, dibutyl amine, tributyl amine, hydroxylamine,
diethylhydroxylamine, diethylhydroxyl amine anhydride, pyridine,
and picoline.
138. The method as set forth in claim 133, wherein said chemical
solution contains said amine in the range of 0.01 to 10 weight %
both inclusive.
139. The method as set forth in claim 134, wherein said chemical
solution contains said amine in the range of 0.01 to 10 weight %
both inclusive.
140. The method as set forth in claim 138, wherein said chemical
contains said amine in the range of 0.05 to 5 weight % both
inclusive.
141. The method as set forth in claim 139, wherein said chemical
contains said amine in the range of 0.05 to 5 weight % both
inclusive.
142. The method as set forth in claim 140, wherein said chemical
contains said amine in the range of 0.05 to 2.0 weight % both
inclusive.
143. The method as set forth in claim 141, wherein said chemical
contains said amine in the range of 0.05 to 2.0 weight % both
inclusive.
144. The method as set forth in claim 101, wherein said chemical
solution used in said first chemical-solution step contains
anticorrosive.
145. The method as set forth in claim 102, wherein said chemical
solution used in said second chemical-solution step contains
anticorrosive.
146. The method as set forth in claim 46, wherein said organic film
pattern is comprised of an organic film pattern to which at least
one of a light-exposure step, a developing step, a wet etching
step, and a dry etching step is applied, before processed.
147. A method of fabricating an apparatus including a substrate
processed in accordance with the method defined in claim 46.
148. The method as set forth in claim 147, wherein said apparatus
is comprised of one of a semiconductor device, a liquid crystal
display device, an electro-luminescence (EL) display device, a
field emission display device and a plasma display device.
149. A chemical solution used in the first chemical-solution step
defined in claim 101, containing at least one of acid chemical,
organic solvent, alkaline chemical, amine, organic solvent and
amine, and alkaline chemical and amine.
150. A chemical solution used in the second chemical-solution step
defined in claim 102, containing at least one of acid chemical,
organic solvent, alkaline chemical, amine, organic solvent and
amine, and alkaline chemical and amine.
151. The chemical solution as set forth in claim 149, wherein said
organic solvent contains at least amine.
152. The chemical solution as set forth in claim 150, wherein said
organic solvent contains at least amine.
153. The chemical solution as set forth in claim 149, wherein said
alkaline chemical contains at least amine and water.
154. The chemical solution as set forth in claim 150, wherein said
alkaline chemical contains at least amine and water.
155. The chemical solution as set forth in claim 149, wherein said
amine is selected from a group consisting of monoethyl amine,
diethyl amine, triethyl amine, monoisopyl amine, diisopyl amine,
triisoply amine, monobutyl amine, dibutyl amine, tributyl amine,
hydroxylamine, diethylhydroxylamine, diethylhydroxylamine
anhydride, pyridine, and picoline.
156. The chemical solution as set forth in claim 150, wherein said
amine is selected from a group consisting of monoethyl amine,
diethyl amine, triethyl amine, monoisopyl amine, diisopyl amine,
triisoply amine, monobutyl amine, dibutyl amine, tributyl amine,
hydroxylamine, diethylhydroxylamine, diethylhydroxylamine
anhydride, pyridine, and picoline.
157. The chemical solution as set forth in claim 149, wherein said
chemical solution contains said amine in the range of 0.01 to 10
weight % both inclusive.
158. The chemical solution as set forth in claim 150, wherein said
chemical solution contains said amine in the range of 0.01 to 10
weight % both inclusive.
159. The chemical solution as set forth in claim 157, wherein said
chemical contains said amine in the range of 0.05 to 5 weight %
both inclusive.
160. The chemical solution as set forth in claim 158, wherein said
chemical contains said amine in the range of 0.05 to 5 weight %
both inclusive.
161. The chemical solution as set forth in claim 157, wherein said
chemical contains said amine in the range of 0.05 to 2.0 weight %
both inclusive.
162. The chemical solution as set forth in claim 158, wherein said
chemical contains said amine in the range of 0.05 to 2.0 weight %
both inclusive.
163. The chemical solution as set forth in claim 149, wherein said
chemical solution used in said first chemical-solution step
contains anticorrosive.
164. The chemical solution as set forth in claim 150, wherein said
chemical solution used in said second chemical-solution step
contains anticorrosive.
Description
CROSS REFERENCE TO THE RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 11/754,827, filed May 29, 2007, which claims priority from
Japanese Patent Application No. 2006-147810, filed May 29, 2006,
the contents of all of which is incorporated herein by reference in
their entirety.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to an apparatus for processing
a substrate, a method of doing the same, and chemical solution to
be used in the method.
[0004] 2. Description of the Related Art
[0005] A wiring in a circuit has been conventionally formed, for
instance, by forming an organic film pattern on a semiconductor
wafer, a liquid crystal display (LCD) substrate or other
substrates, and etching a film underlying the organic film pattern,
that is, the substrate with the organic film pattern being used as
a mask to thereby pattern the underlying film. After the underlying
film has been patterned, the organic film pattern is removed.
[0006] For instance, Japanese Patent Application Publications Nos.
2002-202619, 2002-334830, 2005-159292, 2005-159342, and 2005-159293
have suggested a method of processing an organic film pattern,
including processing an underlying film, deforming an organic film
pattern, etching the underlying film with the deformed organic film
pattern being used as a mask, and removing the organic film
pattern.
[0007] Specifically, the suggested method includes a step of
deforming an organic film pattern (hereinafter, referred to as
"fusion/deformation step", or referred to as "gas-atmosphere
applying step" because the "fusion/deformation step" is carried out
by exposing a substrate to gas atmosphere), patterning an
underlying film with the deformed organic film pattern being used
as a mask, and removing the organic film pattern.
[0008] Namely, the suggested method includes the fusion/deformation
step (specifically, the gas-atmosphere applying step) as a
principal step.
[0009] In order to stably carry out those steps, the method may
include steps of controlling (specifically, lowering) a temperature
of a substrate to a suitable temperature, and heating the organic
film pattern to be able to readily bake the organic film pattern
after the organic film pattern has been deformed. The step of
heating the organic film pattern may be carried out by broadening a
range of a temperature in which the step of controlling a
temperature of a substrate is carried out.
[0010] FIGS. 11A, 11B and 11C show steps to be carried out in the
above-mentioned related method.
[0011] As illustrated in FIG. 11A, the first related method of
processing a substrate includes in sequence of a
substrate-temperature controlling step S102 of controlling a
temperature of a substrate, a gas-atmosphere applying step S103 of
applying gas atmosphere to the substrate, a heating step S104 of
heating the substrate, and a substrate-temperature controlling step
of S1021 of controlling a temperature of the substrate.
[0012] As illustrated in FIG. 11B, the second related method of
processing a substrate includes in sequence of a first removal step
J1, a substrate-temperature controlling step S102 of controlling a
temperature of a substrate, a gas-atmosphere applying step S103 of
applying gas atmosphere to the substrate, a heating step S104 of
heating the substrate, and a substrate-temperature controlling step
of S1021 of controlling a temperature of the substrate.
[0013] As illustrated in FIG. 11C, the third related method of
processing a substrate includes in sequence of a first removal step
J1, a second removal step J2, a substrate-temperature controlling
step S102 of controlling a temperature of a substrate, a
gas-atmosphere applying step S103 of applying gas atmosphere to the
substrate, a heating step S104 of heating the substrate, and a
substrate-temperature controlling step of S1021 of controlling a
temperature of the substrate.
[0014] The steps illustrated in each of FIGS. 11A, 11B and 11C
define a process of patterning an organic film formed on a
substrate.
[0015] The first removal step J1 shown in FIGS. 11B and 11C may be
comprised of a first chemical-solution step S1, an ashing step S7,
or a combination of an ashing step S7 and a first chemical-solution
step S1 (these steps are explained later in detail with reference
to FIG. 2).
[0016] The second removal step J2 shown in FIG. 11C may be
comprised of a second chemical-solution step S5, an ashing step S7,
or a combination of an ashing step S7 and a second
chemical-solution step S5 (these steps are explained later in
detail with reference to FIG. 3).
[0017] Each of the first removal step J1 and the second removal
step J2 is carried out in order to remove an alterated layer or a
deposited layer both formed on an organic film pattern, to
selectively remove only an alterated layer or a deposited layer, or
to remove an alterated layer or a deposited layer to thereby cause
a non-alterated portion of an organic film pattern to appear.
[0018] The substrate-temperature controlling step S102 of
controlling a temperature of a substrate may be omitted.
[0019] The gas-atmosphere applying step S103 of applying gas
atmosphere to a substrate, in the methods shown in FIGS. 11A, 11B
and 11C, acts as a fusion/deformation step, namely, has a function
of fusing and thereby deforming an organic film pattern.
[0020] In the gas-atmosphere applying step S103, an organic film
pattern is exposed to gas atmosphere obtained by vaporizing an
organic solvent such as alcohol (R--OH), alkoxyalcohol, ether
(R--O--R, Ar--O--R, Ar--O--Ar), ester, ketone, glycol, alkylene
glycol, and glycol ether (R indicates an alkyl group or a
substituted alkyl group, Ar indicates a phenyl group or an aromatic
ring other than a phenyl group), and thus, the organic solvent
penetrates the organic film pattern. As a result, the organic film
pattern is fused, and thus, liquidized or fluidized (hereinafter,
referred to as "chemical-solution fusion reflow"). Thus, the
organic film pattern is deformed.
[0021] The chemical-solution fusion reflow step causes an organic
film pattern to deform in the range of 5 to 20 micrometers. It is
sometimes possible to deform an organic film pattern by 100
micrometers or more.
[0022] However, since an organic film pattern is much deformed, if
the organic film pattern is required to be accurately patterned, it
would be necessary to accurately control the deformation of the
organic film pattern.
[0023] In order to reduce a number of photolithography steps, there
may be used an organic film pattern (specifically, a resist
pattern) for forming a source and a drain in a channel. The
fusion/deformation step is used for deforming two separate portions
of the resist pattern located in the vicinity of a channel,
corresponding to the source and drain, thereby unifying the
separate two portions to each other.
[0024] It is necessary to cause much "chemical-solution fusion
reflow" in order to stably unify the separate two portions to each
other. However, if "chemical-solution fusion reflow" is carried out
so much, a resist pattern associated with portions other than a
channel, such as wirings, would be much fused and deformed.
[0025] Accordingly, it was necessary to design a resist pattern to
have two portions having different thicknesses from each other, and
to remove a thinner portion of the resist pattern before carrying
out the fusion/deformation step.
[0026] However, since an organic film pattern would have an
increased area due to the fusion/deformation step, it would be
necessary to accurately control a time for carrying out the
fusion/deformation step to thereby control accurately the
deformation of an organic film pattern, in order to prevent an area
of the organic film pattern from increasing.
[0027] Though there is a need for a process which is capable of
reducing costs and saving energies and resources, there were not
suggested an effective apparatus and method for doing so.
SUMMARY OF THE INVENTION
[0028] In view of the above-mentioned problems in the related art,
it is an exemplary object of the present invention to provide an
apparatus for processing a substrate which is capable of preventing
an organic film pattern from having an unnecessarily increased area
in the fusion/deformation step, and accurately controlling
deformation of an organic film pattern.
[0029] It is also an exemplary object of the present invention to
provide a method of processing a substrate, and a chemical solution
used in the method both of which are capable of doing the same as
mentioned above.
[0030] In the apparatus and the method both in accordance with the
present invention, a fusion/deformation step (specifically, a
gas-atmosphere applying step) is carried out similarly to the
above-mentioned related method, but thereafter, a part of an
organic film pattern (for instance, a resist pattern) having an
area having been increased more than necessary due to
fusion/deformation reflow, that is, an unnecessary portion of an
organic film pattern is removed.
[0031] Hereinbelow are explained an apparatus for processing a
substrate, a method of doing the same, and a chemical solution used
in the method all in accordance with the present invention.
[0032] The apparatus for processing a substrate in accordance with
the present invention is designed to have processing units selected
for carrying out the method of processing a substrate, and to
control the processing units to operate in an order corresponding
to an order in which steps defining the method are carried out.
[0033] In a first exemplary aspect of the present invention, there
is provided an apparatus for processing a substrate, including a
gas-atmosphere applying unit for applying gas atmosphere to the
substrate, and a light-exposure unit for exposing the substrate to
light through a lower surface of the substrate.
[0034] There is further provided an apparatus for processing a
substrate, including a light-exposure unit for exposing the
substrate to light through a lower surface of the substrate, and a
chemical-solution applying unit for applying chemical solution to
the substrate.
[0035] There is still further provided an apparatus for processing
a substrate, including a substrate carrier for carrying the
substrate, a gas-atmosphere applying unit for applying gas
atmosphere to the substrate, a third processing unit for applying a
third removal step to the substrate, and a controller for
controlling the substrate carrier, the gas-atmosphere applying unit
and the third processing unit such that a step of applying gas
atmosphere to the substrate, to be carried out by the
gas-atmosphere applying unit, and the third removal step to be
carried out by the third processing unit are carried out in this
order.
[0036] In a second exemplary aspect of the present invention, there
is provided a method of processing an organic film pattern formed
on a substrate, comprising, in sequence of, a fusion/deformation
step of fusing and thereby deforming the organic film pattern, and
a third removal step of removing at least a part of the fused and
deformed organic film pattern.
[0037] In a third exemplary aspect of the present invention, there
is provided a method of fabricating an apparatus including a
substrate processed in accordance with the above-mentioned
method.
[0038] In a fourth exemplary aspect of the present invention, there
is provided a chemical solution used in a first chemical-solution
step, containing at least one of acid chemical, organic solvent,
alkaline chemical, amine, organic solvent and amine, and alkaline
chemical and amine.
[0039] For instance, an unnecessary portion of an organic film
pattern is removed by an ashing step and a chemical-solution step
alone or in combination. In the chemical-solution step, there is
used chemical solution having a function of developing an organic
film pattern or a function of separating an organic film
pattern.
[0040] If necessary, a step of removing an alterated layer or a
deposited layer formed on a surface of an organic film pattern may
be carried out before the fusion/deformation step.
[0041] Specifically, in the method in accordance with the present
invention, after the fusion/deformation step has been carried out
for fusing and thereby deforming an organic film pattern formed on
a substrate, an unnecessary portion of the organic film pattern or
a portion of the organic film pattern having an area having
increased more than necessity is at least partially removed by
various removal steps (defined in "third removal step" in
claims).
[0042] In the above-mentioned related art, an area of an organic
film pattern is only increased due to the fusion/deformation
reflow, and an increasing rate is controlled by controlling a
period of time during which the fusion/deformation reflow is
carried out, for instance. In contrast, the present invention makes
it possible to control an area of an organic film pattern in
opposite ways. That is, the present invention provides the second
control to an area of an organic film pattern by removing or
contracting the organic film pattern after the fusion/deformation
reflow was carried out, ensuring that the deformation of an organic
film pattern can be accurately controlled.
[0043] In order to reduce a number of photolithography steps in the
above-mentioned related art, there was used an organic film pattern
(specifically, a resist pattern) for forming a source and a drain
in a channel. The fusion/deformation step was used for deforming
two separate portions of the resist pattern located in the vicinity
of a channel, corresponding to the source and drain, thereby
unifying the separate two portions to each other.
[0044] However, if the chemical-solution fusion reflow caused by
the fusion/deformation step is small, it was not possible to surely
unify the separate two portions of an organic film pattern to each
other, but there is less generated a portion of an organic film
pattern having an area increased more than necessary. If the
chemical solution fusion reflow caused by the fusion/deformation
step is large, there was much generated a portion of an organic
film pattern having an area increased more than necessary, but it
is possible to surely unify the separate two portions of an organic
film pattern to each other.
[0045] In contrast, when the method in accordance with the present
invention is used for reducing a number of photolithography steps,
the chemical-solution reflow is caused sufficiently large due to
the fusion/deformation step, and then, a deformed portion of the
organic film pattern is removed or contracted, thereby the deformed
portion of the organic film pattern would have a desired area.
Thus, the method in accordance with the present invention provides
only the merits obtained in the above-mentioned related art.
[0046] For instance, the fusion/deformation step may be carried out
by causing chemical solution (for instance, organic solvent) to
penetrate an organic film pattern formed on a substrate, to thereby
deform the organic film pattern.
[0047] Specifically, for instance, the fusion/deformation step may
be comprised of a gas-atmosphere applying step in which chemical
solution (for instance, organic solvent) is gasified by nitrogen
(N.sub.2) bubbling, and a substrate is exposed to the thus
generated gas atmosphere.
[0048] Specifically, the fusion/deformation step is carried out in
order to enlarge an area of an organic film pattern, unify organic
film patterns disposed adjacent to each other, planarize an organic
film pattern, or deform an organic film pattern so as to turn the
organic film pattern into an electrically insulating film covering
a circuit pattern formed on a substrate.
[0049] For instance, an organic film pattern to be first formed on
a substrate may be formed by printing or photolithography.
[0050] Furthermore, it is preferable that an organic film pattern
is comprised of a photosensitive organic film, in which case, the
photosensitive film may be a positive type photosensitive organic
film or a negative type photosensitive organic film.
[0051] It is preferable that the positive type photosensitive
organic film contain novolak resin as a primary constituent.
However, the positive type photosensitive organic film may be
composed of resin other than novolak.
[0052] The photosensitive organic film may be alkali-soluble when
exposed to light.
[0053] An underlying film located below an organic film pattern may
be patterned by etching with the organic film pattern being used as
a mask, before the fusion/deformation step is carried out. When an
underlying film located below an organic film pattern is to be
patterned again with the organic film pattern having been already
processed, being used as a mask, the organic film pattern may be
comprised of a film to which at least one of a light-exposure step,
a development step, a wet-etching step, and a dry-etching step is
applied before the fusion/deformation step is carried out.
[0054] The above-mentioned alterated layer formed on an organic
film pattern is caused when (a) a surface of an organic film
pattern is alterated due to at least one of aging, thermal
oxidation, and heat curing, (b) a surface of an organic film
pattern is alterated due to etchant used for wet-etching, (c) a
surface of an organic film pattern is alterated due to dry-etching
or ashing, or (d) a surface of an organic film pattern is alterated
due to deposition caused by dry-etching.
[0055] The above-mentioned deposited layer is formed on a surface
of an organic film pattern by dry-etching, for instance.
[0056] In a first aspect, the method of a processing a substrate,
in accordance with the present invention, includes a
fusion/deformation step (that is, a gas-atmosphere applying step in
which an organic film pattern is exposed to gas atmosphere
generated by vaporizing organic solvent), and a third removal
step.
[0057] Specifically, the method in accordance with the present
invention in a first aspect includes, in sequence of, a
fusion/deformation step (hereinafter, referred also to "a
gas-atmosphere applying step") for fusing and thereby deforming an
organic film pattern, and a third removal step.
[0058] Furthermore, in order to stably carry out those steps, the
method may include a substrate-temperature controlling step of
controlling (specifically, lowering) a temperature of a substrate
to a suitable temperature before the substrate is processed, and a
heating step of heating an organic film pattern to be able to
readily bake the organic film pattern after the organic film
pattern has been deformed. The heating step of heating the organic
film pattern may be carried out by broadening a range of a
temperature in which the step of controlling a temperature of a
substrate is carried out.
[0059] FIG. 1A is a flow chart showing steps to be carried out in
the method in accordance with the present invention in a first
aspect.
[0060] As illustrated in FIG. 1A, the method includes, in sequence
of, a first heating step S9 of heating a substrate and therefore an
organic film pattern, a substrate-temperature controlling step S2
of controlling a temperature of a substrate and therefore an
organic film pattern, a gas-atmosphere applying step S3 of applying
gas atmosphere to an organic film pattern, a second heating step S4
of heating a substrate and therefore an organic film pattern, a
second substrate-temperature controlling step S21 of controlling a
temperature of a substrate and therefore an organic film pattern, a
third removal step J3, and a third heating step S8 of heating a
substrate and therefore an organic film pattern.
[0061] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1A may be
omitted.
[0062] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second heating step
S4, the second substrate-temperature controlling step S21, and the
third heating step S8 may be carried out by changing a temperature
range in a processing unit prepared for carrying out those
steps.
[0063] As explained above, the method in accordance with the
present invention in a first aspect necessarily includes the
gas-atmosphere applying step S3 and the third removal step J3, and
other steps may be omitted, if necessary.
[0064] The method in accordance with the present invention in a
second aspect includes a first removal step, a fusion/deformation
step (that is, a gas-atmosphere applying step in which an organic
film pattern is exposed to gas atmosphere generated by vaporizing
organic solvent), and a third removal step.
[0065] Specifically, the method in accordance with the present
invention in a second aspect includes, in sequence of, a first
removal step, a fusion/deformation step (hereinafter, referred also
to "a gas-atmosphere applying step") for fusing and thereby
deforming an organic film pattern, and a third removal step.
[0066] Furthermore, in order to stably carry out those steps, the
method may include a substrate-temperature controlling step of
controlling (specifically, lowering) a temperature of a substrate
to a suitable temperature before the substrate is processed, and a
heating step of heating an organic film pattern to be able to
readily bake the organic film pattern after the organic film
pattern has been deformed. The heating step of heating the organic
film pattern may be carried out by broadening a range of a
temperature in which the step of controlling a temperature of a
substrate is carried out.
[0067] FIG. 1B is a flow chart showing steps to be carried out in
the method in accordance with the present invention in a second
aspect.
[0068] As illustrated in FIG. 1B, the method includes, in sequence
of, a first removal step J1, a first heating step S9 of heating a
substrate and therefore an organic film pattern, a
substrate-temperature controlling step S2 of controlling a
temperature of the substrate and therefore the organic film
pattern, a gas-atmosphere applying step S3 of applying gas
atmosphere to the organic film pattern, a second heating step S4 of
heating the substrate and therefore the organic film pattern, a
second substrate-temperature controlling step S21 of controlling a
temperature of the substrate and therefore the organic film
pattern, a third removal step J3, and a third heating step S8 of
heating the substrate and therefore the organic film pattern.
[0069] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1B may be
omitted.
[0070] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second
substrate-temperature controlling step S21, the second heating step
S4, and the third heating step S8 may be carried out by changing a
temperature range in a processing unit prepared for carrying out
those steps.
[0071] As explained above, the method in accordance with the
present invention in a second aspect necessarily includes the first
removal step J1, the gas-atmosphere applying step S3 and the third
removal step J3, and other steps may be omitted, if necessary.
[0072] The method in accordance with the present invention in a
third aspect includes a first removal step, a second removal step,
a fusion/deformation step (which is comprised of a gas-atmosphere
applying step in which an organic film pattern is exposed to gas
atmosphere generated by vaporizing organic solvent), and a third
removal step.
[0073] Specifically, the method in accordance with the present
invention in a third aspect includes, in sequence of, a first
removal step, a second removal step, a fusion/deformation step
(hereinafter, referred also to "a gas-atmosphere applying step")
for fusing and thereby deforming an organic film pattern, and a
third removal step.
[0074] Furthermore, in order to stably carry out those steps, the
method may include a substrate-temperature controlling step of
controlling (specifically, lowering) a temperature of a substrate
to a suitable temperature before the gas-atmosphere applying step
is carried out, and a heating step of heating an organic film
pattern to be able to readily bake the organic film pattern after
the organic film pattern has been deformed. The heating step of
heating the organic film pattern may be carried out by broadening a
range of a temperature in which the step of controlling a
temperature of a substrate is carried out.
[0075] FIG. 1C is a flow chart showing steps to be carried out in
the method in accordance with the present invention in a third
aspect.
[0076] As illustrated in FIG. 1C, the method includes, in sequence
of, a first removal step J1, a second removal step J2, a first
heating step S9 of heating a substrate and therefore an organic
film pattern, a substrate-temperature controlling step S2 of
controlling a temperature of the substrate and therefore the
organic film pattern, a gas-atmosphere applying step S3 of applying
gas atmosphere to the organic film pattern, a second heating step
S4 of heating the substrate and therefore the organic film pattern,
a second substrate-temperature controlling step S21 of controlling
a temperature of the substrate and therefore the organic film
pattern, a third removal step J3, and a third heating step S8 of
heating the substrate and therefore the organic film pattern.
[0077] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1C may be
omitted.
[0078] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second
substrate-temperature controlling step S21, the second heating step
S4, and the third heating step S8 may be carried out by changing a
temperature range in a processing unit prepared for carrying out
those steps.
[0079] As explained above, the method in accordance with the
present invention in a third aspect necessarily includes the first
removal step J1, the second removal step J2, the gas-atmosphere
applying step S3 and the third removal step J3, and other steps may
be omitted, if necessary.
[0080] Hereinbelow is explained the above-mentioned first removal
step J1.
[0081] FIGS. 2A, 2B and 2C are flowcharts each showing a step or
steps to be carried out in examples of the first removal step
J1.
[0082] As illustrated in FIG. 2A, a first example of the first
removal step J1 is comprised of a first chemical-solution step S1
for applying chemical solution to an organic film pattern.
[0083] As illustrated in FIG. 2B, a second example of the first
removal step J1 is comprised of an ashing step S7 of ashing an
organic film pattern.
[0084] As illustrated in FIG. 2C, a third example of the first
removal step J1 is comprised of, in sequence, of, an ashing step S7
and a first chemical-solution step S1
[0085] Hereinbelow is explained the above-mentioned second removal
step J2.
[0086] FIGS. 3A, 3B and 3C are flow charts each showing a step or
steps to be carried out in examples of the second removal step
J2.
[0087] As illustrated in FIG. 3A, a first example of the second
removal step J2 is comprised of a second chemical-solution step S5
for applying chemical solution to an organic film pattern.
[0088] As illustrated in FIG. 3B, a second example of the second
removal step J2 is comprised of an ashing step S7 of ashing an
organic film pattern.
[0089] As illustrated in FIG. 3C, a third example of the second
removal step J2 is comprised of, in sequence of, an ashing step S7
and a second chemical-solution step S5.
[0090] Hereinbelow is explained the above-mentioned third removal
step J3.
[0091] FIGS. 4A, 4B, 4C and 4D are flowcharts each showing a step
or steps to be carried out in examples of the third removal step
J3.
[0092] As illustrated in FIG. 4A, a first example of the third
removal step J3 is comprised of a second chemical-solution step S5
for applying chemical solution to an organic film pattern.
[0093] As illustrated in FIG. 4B, a second example of the third
removal step J3 is comprised of an ashing step S7 of ashing an
organic film pattern.
[0094] As illustrated in FIG. 4C, a third example of the third
removal step J3 is comprised of, in sequence of, the first
chemical-solution step S1, and the second chemical-solution step
S5.
[0095] As illustrated in FIG. 4D, a fourth example of the third
removal step J3 is comprised of, in sequence of, an ashing step S7,
and the second chemical-solution step S5.
[0096] The first to third removal steps are carried out for the
following purposes:
[0097] (A) the above-mentioned alterated or deposited layer formed
on a surface of an organic film pattern is selectively removed;
[0098] (B) the above-mentioned alterated or deposited layer formed
on a surface of an organic film pattern is removed to thereby cause
a non-alterated portion of the organic film pattern to appear;
[0099] (C) a part of a non-alterated portion of an organic film
pattern is removed;
[0100] (D) the above-mentioned alterated or deposited layer
existing on the fused/deformed organic film pattern or existing
around the fused/deformed organic film pattern is selectively
removed;
[0101] (E) the above-mentioned alterated or deposited layer
existing on the fused/deformed organic film pattern or existing
around the fused/deformed organic film pattern is selectively
removed to thereby cause a non-alterated portion of an organic film
pattern to appear;
[0102] (F) the above-mentioned alterated or deposited layer
existing on the fused/deformed organic film pattern or existing
around the fused/deformed organic film pattern is at least removed,
and further, a part of the fused/deformed organic film pattern is
removed; and
[0103] (G) the above-mentioned alterated or deposited layer
existing on the fused/deformed organic film pattern or existing
around the fused/deformed organic film pattern is selectively
removed, and further, a part of the fused/deformed organic film
pattern is removed.
[0104] In the above-mentioned ashing step, films formed on a
substrate are etched through the use of at least one of plasma,
ozone and ultraviolet rays.
[0105] A degree of alteration and a characteristic of an alterated
layer depend highly on chemical solution to be used in wet-etching,
whether dry-etching is isotropic or anisotropic, whether deposition
exists on an organic film pattern, and gas used in dry-etching.
Hence, difficulty in removing an alterated layer depends also on
those. Thus, an optimal removal step is selected in accordance with
a degree of alteration and a characteristic of an alterated layer
among the first to third removal steps of the present invention
[0106] The ashing step is carried out for removing only a surface
of the alterated or deposited layer in the first to third removal
steps, and the rest of the alterated or deposited layer is
preferably removed by the first or second chemical solution step
both of which is a wet step.
[0107] In comparison with the steps illustrated in FIGS. 2B, 3B and
4B in which the removal step is comprised only of an ashing step,
the steps illustrated in FIGS. 2C, 3C and 4D make it possible to
shorten a period of time for carrying out an ashing step to an
organic film pattern, and further, to prevent a substrate and an
organic film pattern from being damaged by an ashing step,
providing an advantage that it is possible to remove an alterated
or deposited layer firmly formed on an organic film pattern.
[0108] The first, second and third heating steps are carried out
for the following purposes:
[0109] (A) water, acid solution or alkali solution penetrating an
organic film pattern before the fusion/deformation step is carried
out is removed; and
[0110] (B) when an adhesive force between an organic film pattern
and a substrate or an underlying film is lowered, the adhesive
force is enhanced.
[0111] For instance, a step of heating an organic film pattern to
form the organic film pattern, the first heating step, the second
heating step, and the third heating step are carried out under the
following conditions:
[0112] (A) the first heating step is carried out at a temperature
lower than a temperature at which the second heating step is
carried out;
[0113] (B) a heating step for forming the organic film pattern and
the first heating step are carried out at a temperature lower than
a temperature at which the second heating step is carried out;
[0114] (C) the second heating step is carried out at a temperature
lower than a temperature at which the third heating step is carried
out;
[0115] (D) a heating step for forming the organic film pattern, the
first heating step, and the second heating step are carried out at
a temperature lower than a temperature at which the third heating
step is carried out;
[0116] (E) the first heating step is carried out at a temperature
lower than a temperature at which the third heating step is carried
out;
[0117] (F) a heating step for forming the organic film pattern and
the first heating step are carried out at a temperature lower than
a temperature at which the third heating step is carried out;
[0118] (G) a heating step for forming the organic film pattern, the
first heating step, the second heating step or the third heating
step is carried out at a temperature equal to or smaller than a
temperature at which the organic film pattern is cross-linked (for
instance, a heating step for forming the organic film pattern, the
first heating step, the second heating step or the third heating
step is carried out preferably at a temperature in the range of 50
to 150 degrees centigrade both inclusive, and more preferably at a
temperature in the range of 100 to 130 degrees centigrade both
inclusive); and
[0119] (H) a heating step for forming the organic film pattern, the
first heating step, the second heating step, and the third heating
step are carried out for 60 to 300 seconds both inclusive.
[0120] The above-mentioned conditions (A) to (F) are carried out
for removing an organic film pattern after carrying out the heating
step by means of a developing function of the organic film pattern
(for instance, when an organic film pattern is comprised of a
photosensitive organic film).
[0121] The above-mentioned condition (G) shows an example of a
temperature for maintaining a function of developing an organic
film pattern, and further for enabling an organic film pattern to
be well separated from a substrate.
[0122] The above-mentioned condition (J) shows an example of a
period of time for carrying out the heating step, taking into
consideration a yield when a substrate is processed one by one.
[0123] The above-mentioned fusion/deformation step may be comprised
of the following step, for instance:
[0124] (A) a step of enlarging an area of an organic film
pattern;
[0125] (B) a step of unifying organic film patterns disposed
adjacent to each other, into a single pattern;
[0126] (C) a step of planarizing an organic film pattern;
[0127] (D) a step of deforming an organic film pattern such that
the organic film pattern is turned into an electrically insulating
film covering a circuit pattern formed on a substrate; and
[0128] (E) a step of deforming an organic film pattern by causing
the organic film pattern to make contact with organic solvent to
thereby cause fusion reflow.
[0129] As the above-mentioned organic solvent used in the
fusion/deformation step, there is used organic solvent containing
at least one of the followings (R indicates an alkyl group or a
substitutional alkyl group, and Ar indicates a phenyl group or an
aromatic ring other than a phenyl group):
[0130] alcohol (R--OH);
[0131] ether (R--O--R, Ar--O--R, Ar--O--Ar):
[0132] ester;
[0133] ketone; and
[0134] glycol ether.
[0135] In order to cause the organic solvent to make contact with
an organic film pattern (that is, in order to deform an organic
film pattern by the fusion reflow), the organic film pattern may be
exposed to vapors of the organic solvent, or the organic film
pattern may be immersed into the organic solvent.
[0136] The vapors of the organic solvent are provided, for
instance, by heating the organic solvent, or by bubbling the
organic solvent with inert gas (for instance, nitrogen (N.sub.2)
gas or argon (Ar) gas). The vapors of the organic solvent are
directly applied as they are to an organic film pattern, or are
filled in a bomb.
[0137] Thus, it is possible to fill a chamber with gas atmosphere
of the organic solvent, and to cause the organic film pattern to
make contact with the organic solvent by placing a substrate in the
chamber.
[0138] When an organic film pattern is comprised of a
photosensitive organic film, the following conditions may be very
important to stably carry out particular steps (for instance, steps
to be carried out by means of photosensitivity of an organic film
pattern or a developing function of chemical solution):
[0139] (A) after an organic film pattern was originally formed on a
substrate, the organic film pattern is kept not exposed to light
until the fusion/deformation step is carried out; and
[0140] (B) after an organic film pattern was originally formed on a
substrate, the organic film pattern is kept not exposed to light
until a step of exposing the organic film pattern to light or a
step of exposing the organic film pattern to light through a lower
surface of the organic film pattern is carried out.
[0141] The above-mentioned conditions are required because, by
keeping the organic film pattern not exposed to light, it would be
possible to advantageously carry out a step of exposing an organic
film pattern to light, a step of exposing an organic film pattern
to light through a lower surface of the organic film pattern, and a
step of additionally exposing an organic film pattern to light,
ensuring that the development step can be advantageously carried
out.
[0142] The above-mentioned step of additionally exposing an organic
film pattern to light is comprised of a step of exposing an organic
film pattern to light before or immediately before carrying out at
least one of the first and second chemical-solution steps.
[0143] The above-mentioned step of exposing an organic film pattern
to light through a lower surface of the organic film pattern is
carried out between the fusion/deformation step and the third
removal step or between the fusion/deformation step and the second
chemical solution step.
[0144] The above-mentioned step of exposing an organic film pattern
to light through a lower surface of the organic film pattern makes
it possible to selectively remove an unnecessary portion of an
organic film pattern (for instance, a resist pattern) having an
area having been increased due to the fusion reflow caused by the
fusion/deformation step.
[0145] For instance, when an organic film pattern formed above a
data line is to be fused to reflow into a fused/deformed organic
film pattern, but the resultant organic film pattern is desired not
to extend out of a gate line and a data line, the organic film
pattern is exposed to light through a lower surface of a substrate.
As a result, a first portion of the fused/deformed organic film
pattern hidden by a gate line and a data line is not exposed to
light, but a second portion of the fused/deformed organic film
pattern not hidden by a gate line and a data line (that is, the
second portion has a part extending outwardly from a gate line and
a data line). Due to the difference as to whether exposed to light
or not between the first and second portions, it would be possible
to remove the second portion of an organic film pattern by carrying
out the development step.
[0146] Namely, it is possible to carry out the development step for
selectively removing a portion of an organic film pattern in the
above-mentioned second chemical-solution step as the third removal
step, by using chemical solution having a function of developing
the organic film pattern.
[0147] It would be possible to effectively remove an unnecessary
portion of the fused/deformed organic film pattern by exposing the
original organic film pattern to light with a half-tone mask in
advance or by carrying out the light-exposure step during the
development step.
[0148] For instance, an organic film pattern (which will be exposed
to light with an ordinary mask or with a half-tone mask) used for
forming a data line is kept not exposed to light until the
above-mentioned step of exposing the organic film pattern to light
through a lower surface of a substrate is carried out. Then, the
step of exposing the organic film pattern to light through a lower
surface of a substrate is applied to the organic film pattern, and
then, the organic film pattern is developed in the second
chemical-solution step as the third removal step through the use of
chemical solution having a function of developing the organic film
pattern.
[0149] By optimizing a period of time for carrying out the second
chemical-solution step (step of developing the organic film pattern
through the use of chemical solution having a function of
developing the organic film pattern), it is possible to pattern the
fused/deformed organic film pattern only in a data line even after
the fusion reflow. It is preferable that a period of time for
developing the organic film pattern is minimized enough to
completely remove the organic film pattern.
[0150] The above-mentioned step of exposing an organic film pattern
to light or the above-mentioned step of exposing an organic film
pattern to light through a lower surface of the organic film
pattern can be carried out (a) with a photomask, (b) without a
photomask, or (c) with a photomask having a pattern other than a
minute pattern (equal to or smaller than 1 mm).
[0151] The above-mentioned step of exposing an organic film pattern
to light may be comprised of (A) a step of ordinarily exposing an
organic film pattern to light, (B) a step of exposing an organic
film pattern to light only in an area associated with a
predetermined area of a substrate, (C) a step of exposing an
organic film pattern to light at a time only in the above-mentioned
area, (D) a step of scanning the above-mentioned area with
spot-light, (E) the above-mentioned area is equal to or greater
than 1/10 of an area of a substrate, and (F) an organic film
pattern is exposed to ultra-violet rays, fluorescence, or natural
light.
[0152] The above-mentioned steps (A) to (F) may be carried out
singly or in combination.
[0153] The light-exposure step (a) with a photomask is applied to a
photosensitive organic film pattern through the use of chemical
solution having a function of developing the organic film pattern,
in order to newly form a pattern.
[0154] The light-exposure step (b) without a photomask makes it
possible to cause a portion or portions of a substrate to be
sufficiently exposed to light, even if there is irregularity in
exposure of the substrate to light. Namely, the step (b) can
substantially overcome such irregularity, ensuring uniformity in a
development step to be later carried out.
[0155] The above-mentioned first or second chemical-solution step
may be comprised of any one of the following steps:
[0156] (A) a step of developing an organic film pattern through the
use of chemical solution having a function of developing the
organic film pattern;
[0157] (B) a step of developing an organic film pattern through the
use of chemical solution having at least a function of developing
the organic film pattern;
[0158] (C) a N-th step of developing an organic film pattern,
wherein N indicates an integer equal to or greater than two;
[0159] (D) a chemical-solution step of applying chemical solution
not having a function of developing an organic film pattern, but
having a fusing an organic film pattern for removal, to the organic
film pattern; and
[0160] (E) a chemical-solution step of applying chemical solution
for removal to an alterated or deposited layer formed on a surface
of an organic film pattern.
[0161] As chemical solution to be used in the first or second
chemical-solution step, any one or more of the following chemical
solution may be selected.
[0162] (1) chemical solution obtained by diluting separating
agent;
[0163] (2) organic or inorganic alkaline aqueous solution;
[0164] (3) alkaline aqueous solution containing TMAH (tetramethyl
ammonium hydroxide) as a principal constituent;
[0165] (4) alkaline aqueous solution containing at least one of
NaOH or CaOH;
[0166] (5) chemical solution containing at least acid;
[0167] (6) chemical solution containing at least organic
solvent;
[0168] (7) chemical solution containing at least alkaline;
[0169] (8) chemical solution defined in (5), containing at least
amine;
[0170] (9) chemical solution containing at least organic solvent
and amine;
[0171] (10) chemical solution defined in (7), containing at least
amine and water;
[0172] (11) chemical solution containing at least alkaline and
amine;
[0173] (12) chemical solution defined in (8) to (11), containing,
as amine, at least one of monoethyl amine, diethyl amine, triethyl
amine, monoisopyl amine, diisopyl amine, triisoply amine, monobutyl
amine, dibutyl amine, tributyl amine, hydroxylamine,
diethylhydroxylamine, diethylhydroxylamine anhydride, pyridine, and
picoline;
[0174] (13) chemical solution defined in (8) to (12), containing
amine in the range of 0.01 to 10 weight % both inclusive;
[0175] (14) chemical solution defined in (8) to (12), containing
amine in the range of 0.05 to 5 weight % both inclusive;
[0176] (15) chemical solution defined in (8) to (12), containing
amine in the range of 0.05 to 2.0 weight % both inclusive; and
[0177] (16) chemical solution containing anti-corrosive.
[0178] The chemical solution defined in (1) to (16) may be used
singly or in combination.
[0179] An organic film pattern originally formed on a substrate may
have portions having at least two different thicknesses. The
originally formed organic film pattern is processed for one of the
following purposes:
[0180] (A) by applying at least one of the first, second and third
removal steps to an organic film pattern, a portion having a
smaller thickness is selectively further thinned; and
[0181] (B) by applying at least one of the first, second and third
removal steps to an organic film pattern, a portion having a
smaller thickness is selectively removed.
[0182] A step of patterning an underlying film disposed beneath an
organic film pattern may be carried out before or after or during
an organic film pattern is processed. The step of patterning the
underlying film is carried out, for instance, in one of the
following steps:
[0183] (A) a step of patterning an underlying film disposed beneath
the organic film pattern through the use of the organic film
pattern as a mask before carrying out the fusion/deformation
step;
[0184] (B) a step of patterning an underlying film disposed beneath
the organic film pattern through the use of the organic film
pattern as a mask before carrying out the fusion/deformation step,
the first removal step or the first heating step;
[0185] (C) a step of patterning an underlying film disposed beneath
the organic film pattern through the use of the organic film
pattern as a mask before carrying out the third removal step, the
second heating step or the third heating step;
[0186] (D) a step of patterning an underlying film disposed beneath
the organic film pattern through the use of the organic film
pattern as a mask before the organic film pattern is processed;
and
[0187] (E) a step of patterning an underlying film disposed beneath
the organic film pattern through the use of the organic film
pattern as a mask after the organic film pattern has been
processed.
[0188] The above-mentioned steps (A) to (E) may be carried out once
or a plurality of times for patterning an underlying film.
[0189] An underlying film is processed for the following
purposes:
[0190] (A) an underlying film is processed to be tapered or
step-liked; and
[0191] (B) an underlying film is comprised of a plurality of films,
and any one or more of the films is (are) patterned to have
different patterns from others by processing the underlying
film.
[0192] The apparatus for processing a substrate in accordance with
the present invention is comprised of a substrate carrier for
carrying a substrate, processing units optimal for carrying out the
above-mentioned method of processing a substrate in accordance with
the present invention, selected among a plurality of processing
units prepared for carrying out the steps illustrated in FIGS. 1A
to 1C, 2A to 2C, 3A to 3C and 4A to 4D, and a controller which
operates the selected processing units in an order associated with
the method of processing a substrate.
[0193] The following processing units are prepared for carrying out
the steps illustrated in FIGS. 1A to 1C, 2A to 2C, 3A to 3C and 4A
to 4D:
[0194] (a) a substrate-temperature controlling unit for controlling
a temperature of a substrate and therefore an organic film
pattern;
[0195] (b) a gas-atmosphere applying unit for applying gas
atmosphere to an organic film pattern;
[0196] (c) a heating unit for heating an organic film pattern;
[0197] (d) a chemical-solution unit for carrying out a first,
second or third chemical-solution step;
[0198] (e) a development unit used when first, second and third
chemical-solution steps are comprised of a step of developing an
organic film pattern;
[0199] (f) an ashing unit for ashing an organic film pattern;
[0200] (g) a light-exposure unit for exposing an organic film
pattern to light; and
[0201] (h) a back light-exposure unit for exposing an organic film
pattern to light through a lower surface of a substrate.
[0202] A substrate-temperature controlling unit may be used as a
heating unit and vice versa, if a range of a temperature during
which a step of controlling a temperature of a substrate and a step
of heating an organic film pattern are carried out is within an
allowable range of a temperature of the unit, by changing a
temperature to a temperature at which the former or latter step is
to be carried out.
[0203] If the same step is to be carried out at a plurality of
times in the method in accordance with the present invention, the
same processing unit may be operated at a plurality of times.
[0204] In contrast, in order to enhance a processing yield, the
same step may be carried out in parallel in a plurality of
processing units.
[0205] In the explanation made above, the present invention is
applied to a method of processing a substrate such as a
semiconductor substrate or a liquid crystal substrate. It should be
noted that the present invention may be applied to:
[0206] (a) a method of and an apparatus for fabricating a device
including a substrate processed in accordance with the
above-mentioned method or apparatus for processing a substrate;
[0207] (b) a method of and an apparatus for fabricating a display
device;
[0208] (c) a method of and an apparatus for fabricating a
semiconductor device;
[0209] (d) a method of and an apparatus for fabricating a liquid
crystal display device;
[0210] (e) a method of and an apparatus for fabricating an
electroluminescence (EL) display device;
[0211] (f) a method of and an apparatus for fabricating a field
emission display device; or
[0212] (g) a method of and an apparatus for fabricating a plasma
display device.
[0213] In the explanation made above, the present invention is
applied to a substrate. It should be noted that the present
invention may be applied to a method of fabricating a liquid
crystal display device (a vertical electric field type liquid
crystal display device, a horizontal electric field type liquid
crystal display device, a light-transmission type liquid crystal
display device, a light-reflection type liquid crystal display
device, and a half-transmission type liquid crystal display
device), and a display device such as an EL display device, or a
method of fabricating other semiconductor devices.
[0214] The above and other objects and advantageous features of the
present invention will be made apparent from the following
description made with reference to the accompanying drawings, in
which like reference characters designate the same or similar parts
throughout the drawings.
BRIEF DESCRIPTION OF THE DRAWINGS
[0215] FIG. 1A is a flow chart showing steps to be carried out in
the method in accordance with First Example of the present
invention.
[0216] FIG. 1B is a flow chart showing steps to be carried out in
the method in accordance with Second Example of the present
invention.
[0217] FIG. 1C is a flow chart showing steps to be carried out in
the method in accordance with Third Example of the present
invention.
[0218] FIG. 2A is a flow chart showing steps to be carried out in a
first example of the first removal step.
[0219] FIG. 2B is a flow chart showing steps to be carried out in a
second example of the first removal step.
[0220] FIG. 2C is a flow chart showing steps to be carried out in a
third example of the first removal step.
[0221] FIG. 3A is a flow chart showing steps to be carried out in a
first example of the second removal step.
[0222] FIG. 3B is a flow chart showing steps to be carried out in a
second example of the second removal step.
[0223] FIG. 3C is a flow chart showing steps to be carried out in a
third example of the second removal step.
[0224] FIG. 4A is a flow chart showing steps to be carried out in a
first example of the third removal step.
[0225] FIG. 4B is a flow chart showing steps to be carried out in a
second example of the third removal step.
[0226] FIG. 4C is a flow chart showing steps to be carried out in a
third example of the third removal step.
[0227] FIG. 4D is a flow chart showing steps to be carried out in a
fourth example of the third removal step.
[0228] FIG. 5 is a planar view of a first example of an apparatus
for processing a substrate.
[0229] FIG. 6 is a planar view of a second example of an apparatus
for processing a substrate.
[0230] FIG. 7 is a schematic view showing candidates of processing
units to be equipped in an apparatus for processing a
substrate.
[0231] FIG. 8 is a cross-sectional view of an example of a
chemical-solution applying unit for applying chemical solution to
an organic film pattern, or a developing unit.
[0232] FIG. 9 is a cross-sectional view of a first example of a
gas-atmosphere applying unit for applying gas atmosphere to an
organic film pattern.
[0233] FIG. 10 is a cross-sectional view of a second example of a
gas-atmosphere applying unit for applying gas atmosphere to an
organic film pattern.
[0234] FIG. 11A shows steps to be carried out in the first related
method.
[0235] FIG. 11B shows steps to be carried out in the second related
method.
[0236] FIG. 11C shows steps to be carried out in the third related
method.
[0237] FIG. 12 illustrates a degree of alteration of an alterated
layer in dependence on causes by which the alterated layer is
formed.
[0238] FIG. 13 illustrates variation of an alterated layer to which
only an oxygen ashing (isotropic plasma) step of applying oxygen
ashing is applied.
[0239] FIG. 14 illustrates variation of an alterated layer to which
only a chemical-solution applying step of applying chemical
solution is applied.
[0240] FIG. 15 illustrates variation of an alterated layer to which
an oxygen ashing step and a chemical-solution applying step of
applying chemical solution are applied in this order.
[0241] FIG. 16 illustrates a difference with respect to how an
organic film pattern is processed in a fusion/deformation step
between in the method in accordance with the present invention and
in the related method.
[0242] FIG. 17 is a graph showing relation between a concentration
of amine in chemical solution and a removal rate, in association
with whether an organic film pattern is alterated or not.
[0243] FIGS. 18A, 18B, 18C, 18D, 18E, 18F and 18G are plan and
cross-sectional views of a thin film transistor (TFT) device in a
related method of fabricating a TFT substrate, including a
fusion/deformation/reflow process.
[0244] FIGS. 19A, 19B, 19C, 19D, 19E, 19F and 19G are plan and
cross-sectional views of a thin film transistor (TFT) device in a
method of fabricating a TFT substrate, in accordance with Fourth
Example of the present invention.
[0245] FIGS. 20A, 20B, 20C, 20D, 20E, 20F and 20G are plan and
cross-sectional views of a thin film transistor (TFT) device in a
method of fabricating a TFT substrate, in accordance with Fifth
Example of the present invention.
DESCRIPTION OF PREFERRED EMBODIMENTS
[0246] Preferred embodiments in accordance with the present
invention will be explained hereinbelow with reference to
drawings.
[0247] The method in accordance with an embodiment of the present
invention is carried out in an apparatus 100 for processing a
substrate, illustrated in FIG. 5 or an apparatus 200 for processing
a substrate, illustrated in FIG. 6, for instance.
[0248] The apparatus 100 illustrated in FIG. 5 includes a plurality
of processing units, and an order in which the processing units are
operated is variable.
[0249] The apparatus 200 illustrated in FIG. 6 includes a plurality
of processing units, and an order in which the processing units are
operated is fixed.
[0250] The apparatuses 100 and 200 are designed to be able to
selectively have later-mentioned processing units to apply various
steps to a substrate.
[0251] For instance, as illustrated in FIG. 7, the apparatuses 100
and 200 may include eighth processing units, specifically, a simple
light-exposure unit 17 for exposing an organic film pattern to
light, a heating unit 18 for heating an organic film pattern, a
substrate-temperature controlling unit 19 for controlling a
temperature of a substrate and therefore a temperature of an
organic film pattern, a developing unit 20 for developing an
organic film pattern, a chemical-solution applying unit 21 for
applying chemical solution to an organic film pattern, a
gas-atmosphere applying unit 22 for applying gas atmosphere to an
organic film pattern, an ashing unit 23 for applying ashing to an
organic film pattern, and a back light-exposure unit 24 for
exposing an organic film pattern to light through a lower surface
of a substrate.
[0252] The apparatus 100 or 200 is comprised of a substrate carrier
(a substrate-carrier robot), a cassette station in which a cassette
is placed, and one or more processing units selected among the
above-mentioned eight processing units.
[0253] In the light-exposure unit 17 for exposing an organic film
pattern to light, an organic film pattern formed on a substrate is
exposed to light.
[0254] For instance, the light-exposure step of can be carried out
in the light-exposure unit 17 (a) with a photomask, (b) without a
photomask, or (c) with a photomask having a pattern other than a
minute pattern (equal to or smaller than 1 mm).
[0255] The step of exposing an organic film pattern to light may be
comprised of (A) a step of ordinarily exposing an organic film
pattern to light, (B) a step of exposing an organic film pattern to
light only in an area associated with a predetermined area of a
substrate, (C) a step of exposing an organic film pattern to light
at a time only in the above-mentioned area, (D) a step of scanning
the above-mentioned area with spot-light, (E) the above-mentioned
area is equal to or greater than 1/10 of an area of a substrate,
and (F) an organic film pattern is exposed to ultra-violet rays,
fluorescence, or natural light, singly or in combination.
[0256] The light-exposure unit 17 exposes an organic film pattern
to light in accordance with the above-mentioned steps (A) to (F)
singly or in combination.
[0257] The light-exposure step (a) with a photomask is applied to a
photosensitive organic film pattern through the use of chemical
solution having a function of developing the organic film pattern,
in order to newly form a pattern.
[0258] The light-exposure step (b) without a photomask makes it
possible to cause a portion or portions of a substrate to be
sufficiently exposed to light, even if there is irregularity in
exposure of the substrate to light. Namely, the step (b) can
substantially overcome such irregularity, ensuring uniformity in a
development step to be later carried out.
[0259] In the heating unit 18 for heating an organic film pattern,
a substrate and therefore an organic film pattern are heated or
baked in the range of 80 to 180 degrees centigrade both inclusive,
for instance, and preferably in the range of 100 to 150 degrees
centigrade both inclusive.
[0260] The heating unit 18 may be comprised of a stage on which a
substrate is held horizontally, and a chamber in which the stage is
arranged.
[0261] The substrate-temperature controlling unit 19 controls a
temperature of a substrate and therefore an organic film
pattern.
[0262] For instance, the substrate-temperature controlling unit 19
keeps a substrate and an organic film pattern in the range of 10 to
80 degrees centigrade both inclusive, for instance, and preferably
in the range of 10 to 50 degrees centigrade both inclusive, and
more preferably in the range of 20 to 30 degrees centigrade both
inclusive. The substrate-temperature controlling unit 19 can keep
substrate and an organic film pattern at a temperature higher than
the above-mentioned temperatures.
[0263] The substrate-temperature controlling unit 19 can keep a
substrate at a temperature in the range of .+-.2 degrees centigrade
of a target temperature, and preferably at a temperature in the
range of .+-.1 degrees centigrade of a target temperature.
[0264] The substrate-temperature controlling unit 19 is comprised
of a stage on which a substrate is held horizontally, and a chamber
in which the stage is arranged.
[0265] The heating unit 18 and the substrate-temperature
controlling unit 19 can control a broad range of a temperature.
Hence, if one of them can control a temperature from a high
temperature to a low temperature (for instance, 10 to 180 degrees
centigrade), it can carry out the temperature control in place of
the other by changing a range of a temperature to be
controlled.
[0266] In the chemical-solution applying unit 21, chemical solution
is applied to an organic film pattern.
[0267] FIG. 8 is a cross-sectional view of an exemplary structure
of the chemical-solution applying unit 21.
[0268] As illustrated in FIG. 8, the chemical-solution applying
unit 21 is comprised of, for instance, a chemical solution tank 301
in which chemical solution is accumulated, and a chamber 302 in
which a substrate 500 is arranged.
[0269] The chamber 302 includes a movable nozzle 303 for supplying
chemical solution transported from the chemical solution tank 301,
onto the substrate 500, a stage 304 on which the substrate 500 is
held substantially horizontally, and an exhaust outlet 305 through
which exhaust liquid and exhaust gas leave the chamber 302.
[0270] The movable nozzle 303 is designed to be horizontally
movable in the chamber 302
[0271] In the chemical-solution applying unit 21, chemical solution
accumulated in the chemical solution tank 301 can be vaporized by
compressing nitrogen gas into the chemical solution tank 301, that
is, by bubbling the chemical solution with nitrogen gas. The
vaporized chemical solution is supplied onto the substrate 500
through the movable nozzle 303.
[0272] The stage 304 includes a plurality of standing pins for
supporting the substrate 500 at a lower surface thereof.
[0273] The stage 304 is designed to be vertically movable. Thus,
the stage 304 puts the substrate 500 at a variable height in the
chamber 302.
[0274] The chemical-solution applying unit 21 may be designed to be
of a dry type in which chemical is vaporized, and the thus
vaporized chemical is supplied onto the substrate 500.
[0275] For instance, chemical solution used in the
chemical-solution applying unit 21 (namely, chemical solution
accumulated in the chemical solution tank 301) contains at least
one of acid solution, organic solvent and alkaline solution.
[0276] In the developing unit 20 for developing an organic film
pattern, an organic film pattern is developed or overdeveloped.
[0277] For instance, the developing unit 20 may be designed to have
the same structure as that of the chemical-solution applying unit
21 except that developing agent is accumulated in the chemical
solution tank 301. In other words, the chemical-solution applying
unit 21 may be used as the developing unit 20 by accumulating
developing agent in the chemical solution tank 301.
[0278] In the gas-atmosphere applying unit 22, there is carried out
a gas-atmosphere applying step in which various gases are applied
to an organic film pattern to thereby fuse and deform the organic
film pattern (fusion/deformation step).
[0279] FIGS. 9 and 10 are cross-sectional views of an exemplary
structure of the gas-atmosphere applying unit 22.
[0280] As illustrated in FIGS. 9 and 10, the gas-atmosphere
applying unit 22 may be comprised of a container 401 in which a gas
is produced by bubbling, and a chamber 402 in which a substrate 500
is arranged.
[0281] The chamber 402 includes a gas inlet 403 through which a gas
is introduced into the chamber 402 from the container 401, an
exhaust outlet 404 through which gas is exhausted from the chamber
402, a stage 405 for substantially horizontally holding the
substrate 500, and a temperature controller (not illustrated) for
keeping the chamber 402 and the container 401 at a predetermined
temperature.
[0282] The chamber 402 may include a plurality of gas inlets 403
located at different positions from one another, and a gas
distribution plate 406 having a plurality of apertures formed
therethrough for dispersing and distributing gas onto the substrate
500 supported on the stage 405, as illustrated in FIG. 9.
[0283] As an alternative, the chamber 402 may include a single gas
inlet 403, and a distributor 407 distributing gas supplied through
the gas inlet 403, by rotation, and horizontally movable in the
chamber 402, as illustrated in FIG. 10.
[0284] In the gas-atmosphere applying unit 22, liquid (for
instance, organic solvent) accumulated in the container 401 is
bubbled by introducing nitrogen gas thereinto, gas produced by
bubbling the liquid is introduced into the chamber 402 through the
gas inlet 403, and the substrate 500 is exposed to the gas.
[0285] In the ashing unit 23, an organic film pattern formed on the
substrate 500 is etched by plasma (oxygen plasma or oxygen/fluorine
plasma), optical energy of light having a short wavelength, such as
ultra-violet ray, ozone-processing using optical energy or heat, or
other steps.
[0286] In the back light-exposure unit 24, an organic film pattern
formed on a substrate is exposed to light through a lower surface
of the substrate.
[0287] The back light-exposure unit 24 has the same structure as
that of the simple light-exposure unit 17. Accordingly, the simple
light-exposure unit 17 may be substituted for the back
light-exposure unit 24.
[0288] As illustrated in FIG. 5, the apparatus 100 is comprised of
a first cassette station 1 in which a cassette L1 in which a
substrate (for instance, a LCD substrate or a semiconductor wafer)
is accommodated is placed, a second cassette station 2 in which a
cassette L2 similar to the cassette L1 is placed, processing unit
arrangement areas 3 to 11 in each of which processing units U1 to
U9 is arranged, respectively, a robot 12 (a substrate carrier) for
transporting a substrate between the first and second cassette
stations 1 and 2 and the processing units U1 to U9, and a
controller 25 for controlling the robot 12 to transport a
substrate, and the processing units U1 to U9 to carry out various
processes.
[0289] For instance, substrates not yet processed by the apparatus
100 are accommodated in the cassette L1, and substrates having been
processed by the apparatus 100 are accommodated in the cassette
L2.
[0290] Any one of the eight processing units illustrated in FIG. 7
is selected as each of the processing units U1 to U9 to be arranged
in the processing unit arrangement areas 3 to 11.
[0291] The number of processing units is determined in accordance
with a kind of process and a capacity of a processing unit.
Accordingly, no processing unit may be arranged in any one or more
of the processing unit arrangement areas 3 to 11.
[0292] For instance, the controller 25 is comprised of a central
processing unit (CPU) and at least one memory. The memory stores a
control program used for controlling an operation of the processing
units U1 to U9 and the robot 12. The central processing unit
controls the processing units U1 to U9 and the robot 12 in
accordance with the control program.
[0293] The controller 25 selects a program in accordance with a
process to be carried out in each of the processing units U1 to U9
and the robot 12, and executes the selected program to thereby
control operation of the processing units U1 to U9 and the robot
12.
[0294] Specifically, the controller 25 controls an order of
transportation of a substrate carried out by the robot 12, in
accordance with data about an order of processes, to thereby take a
substrate out of the first and second cassette station 1 and 2 and
the processing units U1 to U9, and introduces a substrate into them
in accordance with a predetermined order.
[0295] Furthermore, the controller 25 controls an operation of the
processing units U1 to U9 in accordance with data about process
conditions.
[0296] In the apparatus 100 illustrated in FIG. 5, an order in
which the processing units U1 to U9 are operated is variable.
[0297] In the apparatus 200 illustrated in FIG. 6, an order in
which the processing units U1 to U7 are operated is fixed.
[0298] As illustrated in FIG. 6, the apparatus 200 is comprised of
a first cassette station 13 in which a cassette L1 is placed, a
second cassette station 16 in which a cassette L2 is placed,
processing unit arrangement areas 3 to 9 in each of which
processing units U1 to U7 is arranged, respectively, a first robot
14 for transporting a substrate between the cassette L1 and the
processing unit U1, a second robot 15 for transporting a substrate
between the processing unit U7 between the cassette L2, and a
controller 25 for controlling operation of the first and second
robots 14 and 15 to transport of a substrate and the processing
units U1 to U7 to carry out various processes.
[0299] In the apparatus 200, an order of processes carried out in
the processing units U1 to U7 is fixed. Specifically, processes are
continuously carried out from a processing unit located upstream,
that is, in a direction indicated with an arrow A in FIG. 6.
[0300] Any one of the seven processing units illustrated in FIG. 7
is selected as each of the processing units U1 to U7 to be arranged
in the processing unit arrangement areas 3 to 9.
[0301] The number of processing units is determined in accordance
with a kind of process and a capacity of a processing unit.
Accordingly, no processing unit may be arranged in any one or more
of the processing unit arrangement areas 3 to 9.
[0302] The controller 25 of the apparatus 200 controls the robot 12
such that an order of carrying a substrate is determined in
accordance with a fixed order of processing a substrate.
Specifically, the controller 25 of the apparatus 200 controls the
robot 12 such that a substrate is taken out of or carried into the
first and second cassette stations 1 and 2 and the processing units
U1 to U7 in a predetermined order.
[0303] Furthermore, the controller 25 of the apparatus 200 carries
out processes in the processing units U1 to U7 in a predetermined
order determined in accordance with fixedly determined process
conditions in a method of processing a substrate.
[0304] As mentioned above, the apparatuses 100 and 200 suitable for
carrying out the method of processing a substrate are designed to
include a robot acting as a substrate-carrier, a cassette holder (a
cassette station), and processing units selected among the eight
processing units 17-24 illustrated in FIG. 7.
[0305] Though the apparatuses 100 and 200 illustrated in FIGS. 5
and 6 are designed to include nine and seven processing units,
respectively, the number of processing units to be included in the
apparatuses 100 and 200 may be determined in accordance with a kind
of a process, a capacity of a processing unit, costs and so on.
[0306] Furthermore, though the apparatuses 100 and 200 are designed
to include two cassettes L1 and L2, the number of cassettes may be
determined in accordance with a required capacity, costs and so
on.
[0307] The apparatuses 100 and 200 may include a processing unit or
processing units other than the eight processing units illustrated
in FIG. 7. For instance, the apparatuses 100 and 200 may include a
processing unit for exposing a substrate to light for making a
minute pattern, a processing unit for wet- or dry-etching a
substrate, a processing unit for coating a resist film onto a
substrate, a processing unit for strengthening an adhesion force
between a substrate and an organic film pattern (for instance, a
processing unit using an agent for strengthening an adhesion force
between a substrate and an organic film pattern), or a processing
unit for washing a substrate (dry washing through ultra-violet ray
or plasma, and wet washing through a washing agent).
[0308] If the apparatuses 100 and 200 include a processing unit for
wet-etching or dry-etching a substrate, it would be possible to
pattern an underlying film (for instance, a surface of a substrate)
with an organic film pattern being used as a mask.
[0309] The chemical-solution applying unit 21 may be used as a
processing unit for wet- or dry-etching a substrate, if the
chemical-solution applying unit 21 includes chemical by which an
underlying film can be etched, specifically, etchant containing
acid or alkali.
[0310] In order to uniformize each of processes, the apparatuses
100 and 200 may include a plurality of common processing units for
applying common process to a substrate a plurality of times.
[0311] When the apparatuses 100 and 200 include a plurality of
common processing units for applying common process to a substrate
a plurality of times, it is preferable that a substrate is
processed in the common processing units such that the substrate is
directed in different directions from one another (for instance,
oppositely) in the common processing units.
[0312] In such a case, the apparatuses 100 and 200 are preferably
designed to have a function of directing a substrate differently in
the processing units, ensuring that a substrate is turned in
different directions not manually, but automatically.
[0313] For instance, a substrate can be turned in different
directions in a plane defined by the substrate by designing the
stage 405 illustrated in FIGS. 9 and 10 to be rotatable around a
central axis thereof.
[0314] When the apparatuses 100 and 200 include a single certain
processing unit, it is preferable that a substrate is processed in
the processing unit a plurality of times with the substrate being
directed in different directions from one another in each of the
times.
[0315] For instance, it is preferable that a substrate is processed
in a plurality of directions opposite to each other, in which case,
the apparatuses 100 and 200 are preferably designed to have a
function of processing a substrate in a certain processing unit
with the substrate being directed in different directions from one
another in each of the times.
[0316] It is also preferable that a substrate is processed in a
processing unit in a first direction and further in a second
direction different from the first direction, in which case, the
apparatuses 100 and 200 are preferably designed to have a function
of doing so.
[0317] Hereinbelow are explained examples of the method of
processing a substrate.
First Example
[0318] Hereinbelow is explained the method of a processing a
substrate, in accordance with First Example.
[0319] The method in accordance with First Example is carried out
for the following purposes (a) to (c):
[0320] (a) when an underlying film (for instance, a substrate) is
etched with an organic film pattern (for instance, a resist film)
being used as a mask, the underlying film is etched to be tapered
(for instance, see Japanese Patent Application Publication No.
2002-334830), or etched in a minute size (an organic film pattern
is enlarged with respect to an area, or a contact hole is reduced
with respect to a size to thereby reduce an etching size);
[0321] (b) when an underlying film (for instance, a substrate) is
etched with an organic film pattern (for instance, a resist film)
being used as a mask, the underlying film is etched into a
two-layered structure, two patterns different from each other, or a
combination of a separate pattern and combined patterns (for
instance, see FIGS. 2 and 3 of the above-mentioned Japanese Patent
Application Publication No. 2002-334830), by etching the underlying
film prior to and subsequently to a fusion/deformation step;
and
[0322] (c) when an organic film pattern is electrically insulating,
the organic film pattern is deformed to cause the organic film
pattern to act as an electrically insulating film covering a
circuit pattern formed on a substrate.
[0323] The method in accordance with First Example provides steps
of processing an organic film pattern for accomplishing the
above-mentioned purposes (a) to (c).
[0324] FIG. 1A is a flow chart showing steps to be carried out in
the method in accordance with First Example.
[0325] As illustrated in FIG. 1A, the method includes, in sequence
of, a first heating step S9 of heating a substrate and therefore an
organic film pattern, a substrate-temperature controlling step S2
of controlling a temperature of a substrate and therefore an
organic film pattern, a gas-atmosphere applying step S3 of applying
gas atmosphere to an organic film pattern, a second heating step S4
of heating a substrate and therefore an organic film pattern, a
second substrate-temperature controlling step S21 of controlling a
temperature of a substrate and therefore an organic film pattern, a
third removal step J3, and a third heating step S8 of heating a
substrate and therefore an organic film pattern.
[0326] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1B may be
omitted.
[0327] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second heating step
S4, the second substrate-temperature controlling step S21, and the
third heating step S8 may be carried out by changing a temperature
range in a processing unit prepared for carrying out those
steps.
[0328] The method in accordance with First Example can have
variants as follows.
(Variant 1)
[0329] The method in accordance with the variant 1 includes, in
sequence of, a gas-atmosphere applying step S3 of exposing an
organic film pattern to gas atmosphere to thereby fuse and deform
the organic film pattern, and a third removal step J3 of removing
at least a part of the fused/deformed organic film pattern.
(Variant 2)
[0330] The method in accordance with the variant 2 includes, in
sequence of, a gas-atmosphere applying step S3 of exposing an
organic film pattern to gas atmosphere to thereby fuse and deform
the organic film pattern, a second heating step S4 of heating the
fused/deformed organic film pattern, and a third removal step J3 of
removing at least a part of the fused/deformed organic film
pattern.
(Variant 3)
[0331] The method in accordance with the variant 3 includes, in
sequence of, a gas-atmosphere applying step S3 of exposing an
organic film pattern to gas atmosphere to thereby fuse and deform
the organic film pattern, a second heating step S4 of heating the
fused/deformed organic film pattern, a third removal step J3 of
removing at least a part of the fused/deformed organic film
pattern, a third heating step S8 of heating the fused/deformed
organic film pattern.
(Variant 4)
[0332] The method in accordance with the variant 4 includes, in
sequence of, a first heating step S9 of heating an organic film
pattern, a gas-atmosphere applying step S3 of exposing the organic
film pattern to gas atmosphere to thereby fuse and deform the
organic film pattern, a second heating step S4 of heating the
fused/deformed organic film pattern, a third removal step J3 of
removing at least a part of the fused/deformed organic film
pattern, a third heating step S8 of heating the fused/deformed
organic film pattern.
[0333] The variants 1 to 4 may include a substrate-temperature
controlling step S2 of keeping a temperature of a substrate
constant. The substrate-temperature controlling step S2 is carried
out immediately before the fusion/deformation step S3.
[0334] As explained above, the method in accordance with First
Example necessarily includes the gas-atmosphere applying step S3
and the third removal step J3, and other steps may be omitted, if
necessary.
[0335] In the gas-atmosphere applying step S3, a substrate is
exposed in the gas-atmosphere applying unit 22 to various gases
(for instance, gas originated from organic solvent) to thereby
carry out the fusion/deformation step in which an organic film
pattern formed on a substrate is fused and thereby deformed.
[0336] For instance, the gas-atmosphere applying step S3 is carried
out in gas atmosphere originated from organic solvent.
[0337] In the embodiments or examples mentioned hereinbelow, the
fusion/deformation step is carried out as a gas-atmosphere applying
step in which the following organic solvents are used. Hence, the
fusion/deformation step is treated as being identical to the
gas-atmosphere applying step or as having the same function as the
gas-atmosphere applying step.
[0338] List 1 shows organic solvent to be preferably used in the
gas-atmosphere applying step S3.
[List 1]
[0339] Alcohol (R--OH)
[0340] Alkoxy alcohol
[0341] Ether (R--O--R, Ar--O--R, Ar--O--Ar)
[0342] Ester
[0343] Keton
[0344] Glycol
[0345] Alkylene glycol
[0346] Glycol ether
[0347] In List 1, R indicates an alkyl group or a substitutional
alkyl group, and Ar indicates a phenyl group or an aromatic ring
other than a phenyl group.
[0348] List 2 shows specific organic solvent to be preferably used
in the gas-atmosphere applying step S3.
[List 2]
[0349] CH.sub.3OH, C.sub.2H.sub.5OH, CH.sub.3(CH.sub.2)XOH
[0350] Isopropyl alcohol (IPA)
[0351] Etoxy ethanol
[0352] Methoxy alcohol
[0353] Long-chain alkyl ester
[0354] Monoethanol amine (MEA)
[0355] Monoethyl amine
[0356] Diethyl amine
[0357] Triethyl amine
[0358] Monoisopropyl amine
[0359] Diisopropyl amine
[0360] Triisoproply amine
[0361] Monobutyl amine
[0362] Dibutyl amine
[0363] Tributyl amine
[0364] Hydroxylamine
[0365] Diethylhydroxylamine
[0366] Diethylhydroxylamine anhydride
[0367] pyridine
[0368] picoline
[0369] acetone
[0370] Acetyl acetone
[0371] Dioxane
[0372] Ethyl Acetate
[0373] Buthyl acetate
[0374] Toluene
[0375] Methylethyl ketone (MEK)
[0376] Diethyl ketone
[0377] Dimethyl sulfoxide (DMSO)
[0378] Methylisobutyl ketone (MIBK)
[0379] Butyl carbitol
[0380] n-butylacetate (nBA)
[0381] Gammerbutyrolactone
[0382] Ethylcellosolve acetate (ECA)
[0383] Ethyl lactate
[0384] Pyruvate ethyl
[0385] 2-heptanone
[0386] 3-methoxybutyl acetate
[0387] Ethylene glycol
[0388] Propylene glycol
[0389] Buthylene glycol
[0390] Ethylene Glycol Monoethyl Ether
[0391] Diethylene glycol monoethyl ether
[0392] Ethylene glycol monoethyl ether acetate
[0393] Ethylene glycol monomethyl ether
[0394] Ethylene glycol monomethyl ether acetate
[0395] Ethylene glycol mono-n-buthyl ether
[0396] Polyethylene glycol
[0397] Polypropylene glycol
[0398] Polybuthylene glycol
[0399] Polyethylene glycol monoethyl ether
[0400] Polydiethylene glycol monoethyl ether
[0401] Polyethylene glycol monoethyl ether acetate
[0402] Polyethylene glycol monomethyl ether
[0403] Polyethylene glycol monomethyl ether acetate
[0404] Polyethylene glycol mono-n-buthyl ether
[0405] Methyl-3-methoxypropionate (MMP)
[0406] Propylene glycol monomethyl ether (PGME)
[0407] Propylene glycol monomethyl ether acetate (PGMEA)
[0408] Propylene glycol monopropyl ether (PGP)
[0409] Propylene glycol monoethyl ether (PGEE)
[0410] Ethyl-3-ethoxypropionate (FEP)
[0411] Dipropylene glycol monoethyl ether
[0412] Tripropylene glycol monoethyl ether
[0413] Polypropylene glycol monoethyl ether
[0414] Propylene glycol monomethyl ether propionate
[0415] 3-methoxymethyl propionate
[0416] 3-ethoxymethyl propionate
[0417] N-methyl-2-pyrrolidone (NMP)
[0418] The step of applying gas atmosphere to a substrate through
the use of gas produced from organic solvent is carried out, if an
organic film pattern is fused when organic solvent percolates
thereinto.
[0419] For instance, an organic film pattern is soluble in water,
acid or alkali, the gas-atmosphere applying step may be carried out
through the use of gas produced from aqueous solution, acid
solution or alkaline solution.
[0420] In the gas-atmosphere applying step, organic solvent is
vaporized to gas, and then, a substrate is exposed to the gas. The
gas of the organic solvent are provided, for instance, by heating
the organic solvent, or by bubbling the organic solvent with inert
gas (for instance, nitrogen (N.sub.2) gas or argon (Ar) gas).
[0421] A unit for heating organic solvent to thereby vaporize the
same is comprised of an inner or outer bath containing organic
solvent therein. The unit has a function of directly heating the
organic solvent or heating the bath to thereby vaporize the organic
solvent, and arranging a substrate so as to expose to gas of the
organic solvent. For instance, a substrate is arranged at an upper
side of the bath with a lower surface thereof facing upward. As an
alternative, a substrate is placed on a stage with an upper surface
thereof facing upward (namely, an organic film pattern formed on a
substrate faces upwardly), and gas of organic solvent is sprayed
onto the substrate.
[0422] A unit for bubbling organic solvent with inert gas to
thereby vaporize the organic solvent, and supplying the vaporized
organic solvent together with inert gas includes a tank situated
inside or outside of the unit and containing organic solvent
therein. The unit has a function of bubbling the organic solvent
with inert gas to thereby vaporize the organic solvent, and
supplying the vaporized organic solvent together with inert gas,
and further, placing a substrate on a stage.
[0423] In First Example, gas to be applied to an organic film
pattern is supplied by heating organic solvent or bubbling organic
solvent with inert gas. Gas to be applied to an organic film
pattern may be supplied, for instance, through the use of a gas
bomb or a liquidized-gas bomb.
[0424] In the second heating step S4, a stage of the heating unit
18 is kept at a predetermined temperature (for instance, a
temperature in the range of 80 to 180 degrees centigrade), and a
substrate is kept placed on the stage for a predetermined period of
time (for instance, 3 to 5 minutes).
[0425] The second heating step S4 makes it possible for gas used in
the gas-atmosphere applying step to deeply penetrate an organic
film pattern, and further, to surely cause the fusion/deformation
step to proceed. This means that reflow is additionally caused by
heating.
[0426] The heating reflow readily occurs, if organic solvent much
penetrates the organic film pattern. In comparison with carrying
out only heating reflow by heating, it is effective to carry out
the gas-atmosphere applying step S3 before carrying out the second
heating step S4.
[0427] Furthermore, the second heating step S4 puts the organic
film pattern into a stable condition before the next step, that is,
the third removal step J3 is carried out.
[0428] In particular, when the third removal step J3 is comprised
of the second chemical-solution step in which a developing agent or
chemical solution having a function of developing an organic film
pattern is used, the second heating step S4 puts an organic film
pattern into such a condition as the organic film pattern is
pre-baked before the organic film pattern is developed, ensuring
that a developing rate can be controlled.
[0429] Namely, when the third removal step is comprised of the
second chemical-solution step in which a developing agent or
chemical solution having a function of developing an organic film
pattern is used, a developing rate lowers as a temperature at which
an organic film pattern is heated rises. Thus, it would be possible
to control a degree or an amount of an organic film pattern to be
partially removed, by controlling a period of time for carrying out
the second heating step.
[0430] It should be noted that it is necessary to carry out the
second heating step at a temperature below a temperature at which
resin of which an organic film pattern (in particular, a resist
film) is composed is cross-linked, and thus, a developing rate
significantly reduces or an organic film pattern cannot be
developed.
[0431] For an example of a temperature at which the second heating
step S4 is carried out, when an organic film pattern is comprised
of a positive type photosensitive organic film, and contains
novolak resin as a principal constituent, the second heating step
S4 is carried out preferably in the range of 50 to 150 degrees
centigrade both inclusive, and more preferably in the range of 100
to 130 degrees centigrade both inclusive. By carrying out the
second heating step S4 in such a range of a temperature, it would
be possible to accomplish a slow developing rate, and to control a
removal rate of an organic film pattern, an amount of an organic
film pattern to be removed, and a degree of removal of an organic
film pattern.
[0432] If a temperature at which an organic film pattern is heated
after the organic film pattern was formed and before the second
heating step S4 is carried out is higher than a temperature at
which the second heating step S4 is carried out, the temperature
control resulted from the second heating step S4 would be
meaningless. Accordingly a temperature at which an organic film
pattern is heated before the second heating step S4 is carried out
has to be equal or lower than a temperature at which the second
heating step S4 is carried out.
[0433] In the third removal step J3, a part of an organic film
pattern (for instance, a resist pattern) having an area having
increased more than necessary in the fusion/deformation reflow,
among the organic film pattern having been fused and deformed in
the gas-atmosphere applying step S3, is removed.
[0434] FIGS. 4A, 4B, 4C and 4D are flowcharts each showing a step
or steps to be carried out in examples of the third removal step
J3.
[0435] As illustrated in FIG. 4A, a first example of the third
removal step J3 is comprised of the second chemical-solution step
S5 for applying chemical solution to an organic film pattern. There
is used chemical solution having a function of developing an
organic film pattern or a function of separating an organic film
pattern from a substrate.
[0436] As illustrated in FIG. 4B, a second example of the third
removal step J3 is comprised of the ashing step S7 for ashing an
organic film pattern.
[0437] As illustrated in FIG. 4C, a third example of the third
removal step J3 is comprised of, in sequence of, the first
chemical-solution step S1 in which chemical solution having a
function of removing at least an alterated layer or a deposited
layer both formed at a surface of an organic film pattern), and the
second chemical-solution step S5.
[0438] As illustrated in FIG. 4D, a fourth example of the third
removal step J3 is comprised of, in sequence of, the ashing step
S7, and the second chemical-solution step S5.
[0439] In the ashing step, films formed on a substrate are etched
with at least one of plasma, ozone and ultraviolet rays.
[0440] The removal step J3 may be carried out for the purpose of
removing an alterated layer or a deposited layer both formed at a
surface of the organic film pattern.
[0441] The third removal step may include the first or second
chemical-solution step. The first or second chemical-solution step
may be comprised of any one of the following steps:
[0442] (A) a step of developing an organic film pattern through the
use of chemical solution having a function of developing the
organic film pattern;
[0443] (B) a step of developing an organic film pattern through the
use of chemical solution having at least a function of developing
the organic film pattern;
[0444] (C) a N-th step of developing an organic film pattern,
wherein N indicates an integer equal to or greater than two;
[0445] (D) a chemical-solution step of applying chemical solution
not having a function of developing an organic film pattern, but
having a fusing an organic film pattern for removal, to the organic
film pattern; and
[0446] (E) a chemical-solution step of applying chemical solution
for removal to an alterated or deposited layer formed on a surface
of an organic film pattern.
[0447] As chemical solution to be used in the first and second
chemical-solution steps, any one or more of the following chemical
solution may be used.
[0448] (1) chemical solution obtained by diluting separating
agent;
[0449] (2) organic or inorganic alkaline aqueous solution;
[0450] (3) alkaline aqueous solution containing TMAH (tetramethyl
ammonium hydroxide) as a principal constituent;
[0451] (4) alkaline aqueous solution containing at least one of
NaOH or CaOH;
[0452] (5) chemical solution containing at least acid;
[0453] (6) chemical solution containing at least organic
solvent;
[0454] (7) chemical solution containing at least alkaline;
[0455] (8) chemical solution containing at least amine as organic
solvent;
[0456] (9) chemical solution containing at least organic solvent
and amine;
[0457] (10) alkaline aqueous solution containing at least amine and
water;
[0458] (11) chemical solution containing at least alkaline and
amine;
[0459] (12) chemical solution containing, as amine, at least one of
monoethyl amine, diethyl amine, triethyl amine, monoisopyl amine,
diisopyl amine, triisoply amine, monobutyl amine, dibutyl amine,
tributyl amine, hydroxylamine, diethylhydroxylamine,
diethylhydroxylamine anhydride, pyridine, and picoline;
[0460] (13) chemical solution containing amine in the range of 0.01
to 10 weight % both inclusive;
[0461] (14) chemical solution containing amine in the range of 0.05
to 5 weight % both inclusive;
[0462] (15) chemical solution containing amine in the range of 0.05
to 2.0 weight % both inclusive; and
[0463] (16) chemical solution containing anti-corrosive.
[0464] The above-mentioned chemical solution may be used singly or
in combination.
[0465] A function required in the first chemical-solution step is
different from a function required in the second chemical-solution
step.
[0466] Specifically, the first chemical-solution step is
characterized by a step of applying chemical solution for removal
to an alterated or deposited layer formed on a surface of an
organic film pattern, and the second chemical-solution step is
characterized by (A) a step of developing an organic film pattern
through the use of chemical solution having a function of
developing the organic film pattern, (B) a step of developing an
organic film pattern through the use of chemical solution having a
function of developing at least the organic film pattern, (C) a
N-th step of developing an organic film pattern, wherein N
indicates an integer equal to or greater than two, or (D) a
chemical-solution step of applying chemical solution not having a
function of developing an organic film pattern, but having a fusing
an organic film pattern for removal, to an organic film
pattern.
[0467] One of the first and second chemical-solution steps may have
function and/or performance of the other.
[0468] For instance, the above-mentioned chemical solutions (5) to
(16) are principally used in the first chemical-solution step, and
the above-mentioned chemical solutions (1) to (4) are principally
used in the second chemical-solution step.
[0469] However, the above-mentioned chemical solutions (5) to (16)
may be used in the second chemical-solution step, and the
above-mentioned chemical solutions (1) to (4) may be used in the
first chemical-solution step.
[0470] In the third heating step S8, a stage of the heating unit 18
is kept at a predetermined temperature (for instance, a temperature
in the range of 80 to 180 degrees centigrade), and a substrate is
kept placed on the stage for a predetermined period of time (for
instance, 3 to 5 minutes). The third heating step S8 recovers an
organic film pattern from damages caused to the organic film
pattern by the third removal step J3 (chemical-solution step or
ashing step), or puts an organic film pattern into a stable
condition similarly to the organic film pattern being post-baked
after being developed.
[0471] In First Example, the apparatus 100 or 200 includes at least
the chemical-solution applying unit 21, the substrate-temperature
controlling unit 19, the gas-atmosphere applying unit 22, and the
heating unit 18 as the processing units U1 to U9 or U1 to U7.
[0472] In the apparatus 100, the chemical-solution applying unit
21, the substrate-temperature controlling unit 19, the
gas-atmosphere applying unit 22, and the heating unit 18 may be
arranged arbitrarily.
[0473] The apparatus 100 may be designed to further include the
simple light-exposure unit 17, the ashing unit 23, the
chemical-solution unit 21, the substrate-temperature controlling
unit 19, and the heating unit 18. The apparatus 100 may include a
plurality of certain units in accordance with a capacity of each
unit.
[0474] In contrast, in the apparatus 200, the substrate-temperature
controlling unit 19, the gas-atmosphere applying unit 22, the
heating unit 18, the substrate-temperature controlling unit 19
(second occurrence), the chemical-solution unit 21, and the heating
unit 18 (second occurrence) are necessary to be arranged in this
order in a direction indicated with an arrow A in FIG. 6.
[0475] The apparatus 200 may be designed to further include the
simple light-exposure unit 17, the ashing unit 23, the
chemical-solution unit 21, the substrate-temperature controlling
unit 19, and the heating unit 18.
[0476] In the methods explained hereinafter, it is also necessary
to arrange those processing units 19, 22, 18, 19, 21 and 18 in the
order in the apparatus 200.
[0477] Though FIG. 7 illustrates the back light-exposure unit 24,
it is not used in First Example.
[0478] In accordance with First Example, by carrying out the third
removal step J3, a part of an organic film pattern (for instance, a
resist pattern) having an area having increased more than necessary
in the fusion/deformation reflow, among the organic film pattern
having been fused and deformed in the gas-atmosphere applying step
S3, is removed. Thus, it is possible to pattern an organic film
pattern into a desired pattern with high accuracy.
[0479] The fusion/deformation step carried out as the
gas-atmosphere applying step S3 causes an organic film pattern to
deform in the range of 5 to 20 micrometers (it is possible to
deform an organic film pattern by 100 micrometers or more).
[0480] However, since an organic film pattern is much deformed, if
the organic film pattern is required to be accurately patterned, it
would be necessary to accurately control the deformation of the
organic film pattern.
[0481] In order to reduce a number of photolithography steps, there
may be used an organic film pattern (specifically, a resist
pattern) for forming a source and a drain in a channel. The
fusion/deformation step is used for deforming two separate portions
of the resist pattern located in the vicinity of a channel,
corresponding to the source and drain, thereby unifying the
separate two portions to each other.
[0482] It is necessary to cause much "chemical solution fusion
reflow" in order to stably unify the separate two portions to each
other. However, if "chemical solution fusion reflow" is carried out
so much, a resist pattern associated with portions other than a
channel, such as wirings, would be much fused and deformed.
[0483] Since an area of an organic film pattern is increased in the
fusion/deformation step, it was necessary to accurately control a
period of time for carrying out the gas-atmosphere applying step to
avoid an organic film pattern from having an area increased more
than necessary.
[0484] The third removal step J3 contracts or reduces an area of an
organic film pattern.
[0485] In the third removal step, after an organic film pattern
formed on a substrate has been fused and thereby deformed, at least
a part of an unnecessary portion of the organic film pattern and a
portion of the organic film pattern having an area having increased
more than necessary are removed by various processes.
[0486] Whereas the related method has only a control to an
increasing area of the organic film pattern, for instance, by
controlling a period of time for carrying out the
fusion/deformation reflow process, the method in accordance with
First Example has not only the above-mentioned control, but also a
second control for removing a part of the fused/deformed organic
film pattern or reducing an area of the fused/deformed organic film
pattern. Thus, the method in accordance with First Example makes it
possible to accurately control the deformation of the organic film
pattern.
[0487] In order to reduce a number of photolithography steps in the
above-mentioned related art, there was used an organic film pattern
(specifically, a resist pattern) for forming a source and a drain
in a channel. The fusion/deformation step was used for deforming
two separate portions of the resist pattern located in the vicinity
of a channel, corresponding to the source and drain, thereby
unifying the separate two portions to each other.
[0488] However, if the chemical-solution fusion reflow caused by
the fusion/deformation step is small, it was not possible to surely
unify the separate two portions of an organic film pattern to each
other, but there is less generated a portion of an organic film
pattern having an area increased more than necessary. If the
chemical solution fusion reflow caused by the fusion/deformation
step is large, there was much generated a portion of an organic
film pattern having an area increased more than necessary, but it
is possible to surely unify the separate two portions of an organic
film pattern to each other.
[0489] In contrast, when the method in accordance with First
Example is used for reducing a number of photolithography steps,
the chemical-solution reflow is caused sufficiently large due to
the third removal step, namely, the fusion/deformation step, and
then, a deformed portion of the organic film pattern is removed or
contracted, thereby the deformed portion of the organic film
pattern would have a desired area. Thus, the method in accordance
with First Example provides only the merits obtained in the
above-mentioned related art.
[0490] The third removal step may be comprised of the second
chemical-solution step as a wet process and an ashing step as a dry
process singly or in combination.
[0491] An ashing step as a dry step can be grouped into two
types.
[0492] A first type of ashing is a step other than a
plasma-discharging step. For instance, a first type of ashing is
comprised of a step of applying optical energy of a light having a
short wavelength such as ultra-violet ray, or a step of applying
ozone to an object such as an organic film.
[0493] The first type of ashing exerts less damage on an object,
but has a low processing speed. Accordingly, the first type of
ashing is used merely for changing a surface condition of an
organic film pattern or an underlying film, and is hardly used for
a process required to be carried out at a high rate, such as
removal of an alterated layer formed on an organic film.
[0494] In an ashing step other than a plasma-discharging step,
ozone gas may be applied to an organic film pattern while being
heated, in order to enhance a process rate. However, since an
organic film pattern is heat-cured, and hence, much alterated so as
not to be separated by wet-etching, the step of applying ozone gas
to an organic film pattern is scarcely used.
[0495] A second type of ashing is a plasma-discharging step. A
plasma-discharging step is grouped further into types one and two
in dependence on how discharge is generated.
[0496] A type one is an isotropic plasma-discharging step to be
carried out under a high pressure with low power, and a type two is
an anisotropic plasma-discharging step to be carried out under a
low pressure with high power.
[0497] Both of the type one and two have a process speed higher
than that of the first type of ashing, that is, a step other than
plasma-discharging steps.
[0498] The type two has a higher process speed than the same of the
type one.
[0499] Thus, since the type one and two have a high process speed,
an organic film pattern or an underlying film can be changed with
respect to its surface condition in a short period of time. For
instance, wettability of an organic film pattern or an underlying
film can be enhanced in a short period of time. In addition, the
type one and two can be carried out for removal of an alterated
layer formed on a surface of an organic film pattern, or a
high-speed process such as dry peeling-off.
[0500] However, the second type of ashing, that is, a
plasma-discharging step exerts more damage to an object than the
first type of ashing.
[0501] In particular, an alterated layer formed on an organic film
pattern cannot be sufficiently removed by the first type of
ashing.
[0502] An anisotropic plasma-discharging step (type two) can
sufficiently remove an initially formed alterated layer, but would
exert much damage to an organic film pattern, and resultingly, an
alterated layer is newly formed on the organic film pattern.
Accordingly, it is meaningless to select an anisotropic
plasma-discharging step (type two) for removing an alterated layer
formed on a surface of an organic film pattern.
[0503] Thus, an isotropic plasma-discharging step (type one) is
usually selected for removing an alterated layer formed on a
surface of an organic film pattern.
[0504] However, in the method suggested in the above-mentioned
Japanese Patent Application Publication No. 2002-334830, when an
alterated layer formed on a surface of an organic film pattern is
removed for uniformizing a step of causing chemical (for instance,
organic solvent) to percolate into an organic film pattern for
deforming the organic film pattern, it would be impossible to
completely remove the alterated layer even by the anisotropic
plasma-discharging step (type two) or the isotropic
plasma-discharging step (type one), and it would be also impossible
to prevent a small alterated layer from being formed on an organic
film pattern due to damage newly exerted by the anisotropic and
isotropic plasma-discharging step.
[0505] The inventor found out the problem that even such a small
alterated layer newly formed due to the plasma-discharging step
prevents uniformity of a step of causing chemical solution to
percolate into an organic film pattern for deforming the organic
film pattern.
[0506] That is, the method suggested in the above-mentioned
Publication is accompanied with a problem that since uniformity in
the fusion/deformation step is insufficient as a result that the
organic film pattern is damaged by a plasma-discharging step and
that a small alterated film is newly formed on the organic film
pattern, a step of etching an underlying film to be carried out
subsequently to the fusion/deformation step is insufficiently
carried out.
[0507] In accordance with First Example, removal of an alterated or
deposited layer formed at a surface of an organic film pattern,
which was carried out by ashing in the related method, is carried
out by a wet step, specifically, a step of applying chemical
solution to an organic film pattern. Hence, it is possible to
prevent an organic film pattern or a substrate from being
damaged.
[0508] One of the above-mentioned variants 1 to 4 is selected as
the third removal step J3 taking into consideration the
above-mentioned matter and the matter mentioned later with
reference to FIGS. 12 to 15.
[0509] The second heating step S4 of heating an organic film
pattern may be omitted, in which case, it is unnecessary for the
apparatus 100 or 200 to include the heating unit 18.
[0510] If a temperature at which an organic film pattern is heated
in the heating unit 18 can be accomplished also in the
substrate-temperature controlling unit 19, the second heating step
S4 may be carried out in the substrate-temperature controlling unit
19.
[0511] In FIGS. 2 to 4, a step sandwiched between parentheses may
be omitted, similarly to the heating step S4. Accordingly, a
processing unit associated with a step sandwiched between
parentheses may be also omitted.
[0512] It is preferable that a substrate is cooled down to a room
temperature in the second substrate-temperature controlling step
S21 after the second heating step S4 has been carried out.
[0513] Even if a common step is carried out N times (N is an
integer equal to or greater than two), the apparatus 100 is not
necessary to include common processing units for carrying out the
step, but the apparatus 200 is necessary to include N common
processing units for carrying out the step. For instance, if the
second heating step S4 has to be carried out twice in the apparatus
200, the apparatus 200 has to include two heating units 18. The
same is applied to the methods explained hereinbelow.
Second Example
[0514] The method in accordance with Second Example is explained
hereinbelow.
[0515] The method in accordance with Second Example is carried out
for the above-mentioned purposes (A) to (C), similarly to First
Example. In other words, the method in accordance with Second
Example relates to steps of processing an organic film pattern for
the purposes (A) to (C).
[0516] FIG. 1B is a flow chart showing steps to be carried out in
the method in accordance with Second Example.
[0517] As illustrated in FIG. 1B, the method includes, in sequence
of, a first removal step J1, a first heating step S9 of heating a
substrate and therefore an organic film pattern, a
substrate-temperature controlling step S2 of controlling a
temperature of the substrate and therefore the organic film
pattern, a gas-atmosphere applying step S3 of applying gas
atmosphere to the organic film pattern, a second heating step S4 of
heating the substrate and therefore the organic film pattern, a
second substrate-temperature controlling step S21 of controlling a
temperature of the substrate and therefore the organic film
pattern, a third removal step J3, and a third heating step S8 of
heating the substrate and therefore the organic film pattern.
[0518] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1B may be
omitted.
[0519] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second heating step
S4, the second substrate-temperature controlling step S21, and the
third heating step S8 may be carried out by changing a temperature
range in a processing unit prepared for carrying out those
steps.
[0520] The method in accordance with Second Example can have
variants as follows.
(Variant 1)
[0521] The method in accordance with the variant 1 includes, in
sequence of:
[0522] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0523] (B) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern; and
[0524] (C) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern.
(Variant 2)
[0525] The method in accordance with the variant 2 includes, in
sequence of
[0526] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0527] (B) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0528] (C) a second heating step S4 of heating the fused/deformed
organic film pattern; and
[0529] (D) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern.
(Variant 3)
[0530] The method in accordance with the variant 3 includes, in
sequence of
[0531] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0532] (B) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0533] (C) a second heating step S4 of heating the fused/deformed
organic film pattern;
[0534] (D) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern; and
[0535] (E) a third heating step S8 of heating the fused/deformed
organic film pattern.
(Variant 4)
[0536] The method in accordance with the variant 4 includes, in
sequence of
[0537] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0538] (B) a first heating step S9 of heating an organic film
pattern;
[0539] (C) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0540] (D) a second heating step S4 of heating the fused/deformed
organic film pattern;
[0541] (E) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern; and
[0542] (F) a third heating step S8 of heating the fused/deformed
organic film pattern.
[0543] The variants 1 to 4 may include a substrate-temperature
controlling step S2 of keeping a temperature of a substrate
constant. The substrate-temperature controlling step S2 is carried
out immediately before the fusion/deformation step S3.
[0544] As explained above, the method in accordance with Second
Example necessarily includes the first removal step J1, the
gas-atmosphere applying step S3, and the third removal step J3, and
other steps may be omitted, if necessary.
[0545] The first removal step J1 may be comprised of the first
chemical-solution step of removing an alterated layer or a
deposited layer formed at a surface of the organic film pattern
through the use of acid solution, alkaline solution, organic
solvent and so on, and an ashing step of ashing an organic film
pattern, singly or in combination. Specifically, the first removal
step J1 is carried out in both of the chemical-solution applying
unit 21 and the ashing unit 23.
[0546] By carrying out the first removal step J1, it is possible to
remove an alterated layer or a deposited layer formed at a surface
of the organic film pattern, and further, to enhance wettability of
a surface of a substrate not covered with the organic film
pattern.
[0547] In the first removal step J1, an alterated layer formed at a
surface of an organic film pattern and/or a deposited layer formed
at a surface of an organic film pattern are removed in various
ways.
[0548] FIGS. 2A, 2B and 2C are flow charts each showing a step or
steps to be carried out in examples of the first removal step
J1.
[0549] The first removal step J1 has three examples as follows.
[0550] As illustrated in FIG. 2A, a first example of the first
removal step J1 is comprised of a first chemical-solution step S1
for applying chemical solution to an organic film pattern to remove
an alterated layer or a deposited layer formed at a surface of an
organic film pattern.
[0551] As illustrated in FIG. 2B, a second example of the first
removal step J1 is comprised of an ashing step S7 for ashing an
organic film pattern.
[0552] As illustrated in FIG. 2C, a third example of the first
removal step J1 is comprised of, in sequence of, an ashing step S7,
and a first chemical-solution step S1.
[0553] In the ashing step, films formed on a substrate are etched
through the use of at least one of plasma, ozone and ultraviolet
rays.
[0554] It is preferable in the first chemical-solution step to
determine a period of time for carrying out the first
chemical-solution step or to select chemical solution in order to
selectively remove only an alterated layer or a deposited layer
formed at a surface of an organic film pattern.
[0555] As a result of removal of the alterated or deposited layer,
it is possible to cause a non-alterated portion of an organic film
pattern to appear, or to cause a portion of an organic film pattern
covered with a deposited layer to appear.
[0556] An alterated layer to be removed by the first removal step
is formed as a result that a surface of an organic film pattern is
alterated due to degradation caused by aging, thermal oxidation,
heat curing, adhesion of a deposited layer thereto, acid etchant
(etchant for wet etching), ashing (for instance, O.sub.2 ashing),
or dry etching gas.
[0557] That is, an organic film pattern is physically and
chemically damaged and thus alterated due to the above-mentioned
factors. A degree and character of alteration of an alterated layer
depends highly on chemical solution to be used in wet-etching,
whether plasma process as one of dry-etching is isotropic or
anisotropic, whether deposition exists on an organic film pattern,
and gas used in dry-etching. Hence, difficulty in removing an
alterated layer depends also on those factors.
[0558] A deposited layer to be removed by the first removal step is
formed as a result of dry etching.
[0559] A character of a deposited layer depends on whether plasma
process as one of dry-etching is isotropic or anisotropic, and gas
used in dry-etching. Hence, difficulty in removing a deposited
layer depends also on those factors.
[0560] Accordingly, it is necessary to determine a period of time
for carrying out the first chemical-solution step, and chemical
solution to be used in the first chemical solution step in
accordance with difficulty in removing an alterated layer or a
deposited layer.
[0561] As chemical solution to be used in the first
chemical-solution step, for instance, there is used one of chemical
solution containing alkaline chemical, chemical solution containing
acid chemical, chemical solution containing organic solvent,
chemical solution containing both organic solvent and amine, and
chemical solution containing alkaline and amine.
[0562] Alkaline chemical contains, for instance, amine and water,
and organic solvent contains, for instance, amine.
[0563] Chemical solution containing anticorrosive may be used in
the first chemical-solution step.
[0564] Amine is selected from monoethyl amine, diethyl amine,
triethyl amine, monoisopyl amine, diisopyl amine, triisoply amine,
monobutyl amine, dibutyl amine, tributyl amine, hydroxylamine,
diethylhydroxylamine, diethylhydroxyl amine anhydride, pyridine, or
picoline.
[0565] Among the above-listed amine, one or more of amine may be
contained in chemical solution.
[0566] For instance, it is preferable that chemical solution to
used in the first chemical-solution step is comprised of aqueous
solution containing amine in the range of 0.01 to 10 weight % both
inclusive.
[0567] The substrate-temperature control step S2 is carried out
before the gas-atmosphere applying step S3 in order to keep a
temperature of an organic film pattern constant.
[0568] For instance, an organic film pattern is kept at a
temperature in the range of 10 to 50 degrees centigrade both
inclusive by the substrate-temperature control step S2.
[0569] In the substrate-temperature control step S2, a substrate is
kept placed on a stage of the substrate-temperature controlling
unit 19 which is kept at a temperature at which the gas-atmosphere
applying step S3 is carried out, until a temperature of the
substrate reaches the above-mentioned temperature. For instance, a
substrate is kept placed on the stage for 3 to 5 minutes.
[0570] The first chemical-solution step S1 and the
substrate-temperature control step S2 facilitate gas to penetrate
an organic film pattern in the gas-atmosphere applying step S3 to
be later carried out, ensuring enhancement of a yield and quality
of the gas-atmosphere applying step.
[0571] The gas-atmosphere applying step S3, the second heating step
S4, the second substrate-temperature control step S21, the third
removal step J3 and the third heating step S8 are carried out
similarly to First Example.
[0572] An apparatus for processing a substrate, to be used in
Second Example, is designed to include suitable one or ones among
the units 17 to 23 illustrated in FIG. 7 in accordance with an
order in which steps in Second Example are carried out and times at
which steps in Second Example are carried out.
[0573] In comparison with an apparatus processing a substrate, to
be used in First Example, the apparatus for processing a substrate,
to be used in Second Example, is necessary to additionally include
a unit for carrying out the first removal step J1. Accordingly, the
apparatus to be used in Second Example additionally includes a
processing unit or processing units for carrying out the first
removal step J1 relative to the apparatus to be used in First
Example. For instance, the apparatus to be used in Second Example
additionally includes the chemical-solution applying unit 21 and/or
the ashing unit 23. Except a processing unit or processing units
for carrying out the first removal step J1, the apparatus to be
used in Second Example includes the same processing units as the
processing units included in the apparatus to be used in First
Example.
Third Example
[0574] The method in accordance with Third Example is explained
hereinbelow.
[0575] The method in accordance with Third Example is carried out
for the above-mentioned purposes (A) to (C), similarly to First
Example. In other words, the method in accordance with Third
Example relates to steps of processing an organic film pattern for
the purposes (A) to (C).
[0576] FIG. 1C is a flow chart showing steps to be carried out in
the method in accordance with Third Example.
[0577] As illustrated in FIG. 1C, the method includes, in sequence
of, a first removal step J1, a second removal step J2, a first
heating step S9 of heating a substrate and therefore an organic
film pattern, a substrate-temperature controlling step S2 of
controlling a temperature of the substrate and therefore the
organic film pattern, a gas-atmosphere applying step S3 of applying
gas atmosphere to the organic film pattern, a second heating step
S4 of heating the substrate and therefore the organic film pattern,
a second substrate-temperature controlling step S21 of controlling
a temperature of the substrate and therefore the organic film
pattern, a third removal step J3, and a third heating step S8 of
heating the substrate and therefore the organic film pattern.
[0578] The first heating step S9, the substrate-temperature
controlling step S2, the second heating step S4, the second
substrate-temperature controlling step S21, and the third heating
step S8 embraced with broken-line brackets in FIG. 1C may be
omitted.
[0579] Furthermore, the first heating step S9, the
substrate-temperature controlling step S2, the second heating step
S4, the second substrate-temperature controlling step S21, and the
third heating step S8 may be carried out by changing a temperature
range in a processing unit prepared for carrying out those
steps.
[0580] The method in accordance with Third Example can have
variants as follows.
(Variant 1)
[0581] The method in accordance with the variant 1 includes, in
sequence of:
[0582] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0583] (B) a second removal step J2 of removing a part of the
organic film pattern;
[0584] (C) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern; and
[0585] (D) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern.
(Variant 2)
[0586] The method in accordance with the variant 2 includes, in
sequence of:
[0587] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0588] (B) a second removal step J2 of removing a part of the
organic film pattern;
[0589] (C) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0590] (D) a second heating step S4 of heating the fused/deformed
organic film pattern; and
[0591] (E) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern.
(Variant 3)
[0592] The method in accordance with the variant 3 includes, in
sequence of:
[0593] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0594] (B) a second removal step J2 of removing a part of the
organic film pattern;
[0595] (C) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0596] (D) a second heating step S4 of heating the fused/deformed
organic film pattern;
[0597] (E) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern; and
[0598] (F) a third heating step S8 of heating the fused/deformed
organic film pattern.
(Variant 4)
[0599] The method in accordance with the variant 4 includes, in
sequence of
[0600] (A) a first removal step J1 of removing at least an
alterated layer or a deposited layer formed at a surface of an
organic film pattern;
[0601] (B) a second removal step J2 of removing a part of the
organic film pattern;
[0602] (C) a first heating step S9 of heating an organic film
pattern;
[0603] (D) a gas-atmosphere applying step S3 of exposing the
organic film pattern to gas atmosphere to thereby fuse and deform
an organic film pattern;
[0604] (E) a second heating step S4 of heating the fused/deformed
organic film pattern;
[0605] (F) a third removal step J3 of removing at least a part of
the fused/deformed organic film pattern; and
[0606] (G) a third heating step S8 of heating the fused/deformed
organic film pattern.
[0607] The variants 1 to 4 may include a substrate-temperature
controlling step S2 of keeping a temperature of a substrate
constant. The substrate-temperature controlling step S2 is carried
out immediately before the fusion/deformation step S3.
[0608] As explained above, the method in accordance with Third
Example necessarily includes the first removal step J1, the second
removal step J2, the gas-atmosphere applying step S3 and the third
removal step J3. Other steps may be omitted, if necessary.
[0609] The first removal step J1 to be carried out in Third Example
is identical to the first removal step J1 to be carried out in the
above-mentioned Second Example.
[0610] The second removal step J2 is carried out after the first
removal step J1 in which an alterated or deposited layer formed at
a surface of an organic film pattern is removed has been carried
out. In the second removal step J2, a part of the residual organic
film pattern is removed. Herein, the residual organic film pattern
is a non-alterated portion of the organic film pattern.
[0611] FIGS. 3A, 3B and 3C are flowcharts each showing a step or
steps to be carried out in examples of the second removal step
J2.
[0612] As illustrated in FIG. 3A, a first example of the second
removal step J2 is comprised of a second chemical-solution step S5
for applying chemical solution to an organic film pattern. The
chemical solution used in the first example has a function of
developing an organic film pattern or a function of separating an
organic film pattern.
[0613] As illustrated in FIG. 3B, a second example of the second
removal step J2 is comprised only of an ashing step S7 for ashing
an organic film pattern.
[0614] As illustrated in FIG. 3C, a third example of the second
removal step J2 is comprised of, in sequence of, an ashing step S7,
and a second chemical-solution step S5.
[0615] In the above-mentioned ashing step, films formed on a
substrate are etched through the use of at least one of plasma,
ozone and ultraviolet rays.
[0616] In the second removal step J2, an alterated or deposited
layer formed at a surface of an organic film pattern may be
removed.
[0617] The second chemical-solution step in the first and third
examples is carried out similarly to the second chemical-solution
step in the above-mentioned First Example.
[0618] The substrate-temperature control step S2 is carried out
before the gas-atmosphere applying step S3 in order to keep an
organic film pattern at a constant temperature.
[0619] For instance, an organic film pattern is kept at a
temperature in the range of 10 to 50 degrees centigrade both
inclusive by the substrate-temperature control step S2.
[0620] In the heating step S2, a stage of the substrate-temperature
control unit 19 is kept at a predetermined temperature at which the
gas-atmosphere applying step is carried out, and a substrate is
placed on the stage for a predetermined period of time (for
instance, 3 to 5 minutes).
[0621] The gas-atmosphere applying step S3, the second heating step
S4, the second substrate-temperature control step S21, the third
removal step J3 and the third heating step S8 are carried out
similarly to the First Example.
[0622] An apparatus for processing a substrate, to be used in the
Third Example, is designed to include suitable processing unit or
units among the processing units 17 to 23 illustrated in FIG. 7 in
accordance with an order in which steps in Third Example are
carried out and times at which steps in Third Example are carried
out. The apparatus may include a plurality of the same processing
units in dependence on a particular step or steps.
[0623] In comparison with an apparatus processing a substrate, to
be used in First Example, the apparatus for processing a substrate,
to be used in Third Example, is necessary to additionally include
both a processing unit for carrying out the first removal step J1
and a processing unit for carrying out the second removal step J2.
For instance, the apparatus to be used in Third Example includes
the chemical-solution applying unit 21 and/or the ashing unit 23.
Except a unit for carrying out the first removal step J1 and a unit
for carrying out the second removal step J2, the apparatus to be
used in Third Example includes the same processing units as the
processing units included in the apparatus to be used in First
Example.
[0624] Hereinbelow is explained a step of exposing an organic film
pattern to light, to be carried out in First, Second and Third
Examples.
[0625] The step of exposing an organic film pattern to light is
grouped into a step of exposing an organic film pattern to light
through the use of a mask having a minute pattern, and a step of
exposing an organic film pattern to light in an area covering
therewith a predetermined area (which may be an entire area of a
substrate) of a substrate. The latter step is hereinafter referred
to as a "simple light-exposure step".
[0626] The simple light-exposure step is carried out in the simple
light-exposure unit 17. In the simple light-exposure unit 17, an
organic film pattern is exposed to ultra-violet ray, fluorescent
light, natural light, and other similar lights.
[0627] In the simple light-exposure step, an organic film pattern
covering a part or all of a substrate therewith is exposed to
light. For instance, an organic film pattern covering 1/10 or more
of a total area of a substrate therewith is exposed to light.
[0628] In the simple light-exposure step, an organic film pattern
may be exposed to light at a time in an area corresponding to a
predetermined area of a substrate, or an organic film pattern may
be scanned with spot light in an area corresponding to a
predetermined area of a substrate.
[0629] In First, Second and Third Examples, it is preferable that a
substrate is kept not exposed to light after initial exposure of a
substrate to light for forming an organic film pattern, until
development of the organic film pattern is carried out.
[0630] By doing so, it would be possible to uniformize effect of
development of an organic film pattern, and further uniformize
exposure of a substrate to light in the simple light-exposure
step.
[0631] In order to keep a substrate not exposed to light, all steps
may be administrated for this end, or the apparatus 100 or 200 may
be designed to have a function of doing so. For instance, the
apparatus 100 or 200 is placed entirely in a dark room.
[0632] The simple light-exposure step may be carried out in such a
manner as mentioned below.
[0633] In a first case, an organic film pattern formed on a
substrate kept not exposed to light before the simple
light-exposure step is carried out is exposed to light in the
simple light-exposure step.
[0634] In a second case, when a substrate is exposed to light to
some degree before the simple light-exposure step is carried out
(for instance, when a substrate has been already exposed to
ultra-violet rays, fluorescence or natural light, or when a
substrate was kept exposed to ultra-violet rays, fluorescence or
natural light for a long time), or how degree a substrate is
exposed to light is unknown (for instance, a substrate is
irregularly exposed to light, or a substrate is exposed to light in
no control condition), the simple light-exposure step is carried
out for entirely exposing a substrate to light for uniformizing
exposure of a substrate to light, or for additionally exposing a
substrate to light for precaution.
[0635] The ashing step may be comprised of a dry step such as a
step of applying plasma to an organic film pattern in oxygen
atmosphere or in oxygen/fluorine atmosphere, a step of applying
optical energy of light having a short wavelength such as
ultra-violet ray, to an organic film pattern, or a step of applying
ozone to an organic film pattern through the use of such optical
energy and heat.
[0636] The above-mentioned alterated layer formed on an organic
film pattern, to be removed in the ashing step, is caused due to
degradation caused by aging, thermal oxidation, heat curing,
adhesion of a deposition layer thereto, acid etchant (wet-etching),
O.sub.2 ashing, and other dry etching gases (dry-etching).
[0637] An organic film pattern is physically or chemically damaged
and thus deformed due to the above-mentioned factors. A degree and
character of alteration of an alterated layer depends highly on
chemical solution to be used in wet-etching, whether plasma process
as one of dry-etching is isotropic or anisotropic, whether
deposition exists on an organic film pattern, and gas used in
dry-etching. Hence, difficulty in removing an alterated layer
depends also on those factors.
[0638] A deposited layer formed at a surface of an organic film
pattern, to be removed by the ashing step, is caused by dry
etching.
[0639] A character of a deposited layer depends on whether plasma
process as one of dry-etching is isotropic or anisotropic, and gas
used in dry-etching. Hence, difficulty in removing a deposited
layer depends also on those factors.
[0640] An ashing step as a dry step can be grouped into two
types.
[0641] A first type of ashing is a step other than a
plasma-discharging step. For instance, a first type of ashing is
comprised of a step of applying optical energy of a light having a
short wavelength such as ultra-violet ray, or a step of applying
ozone to an object such as an organic film.
[0642] The first type of ashing exerts less damage on an object,
but has a low processing speed. Accordingly, the first type of
ashing is used merely for changing a surface condition of an
organic film pattern or an underlying film, and is hardly used for
a process required to be carried out at a high rate, such as
removal of an alterated layer formed on an organic film.
[0643] In an ashing step other than a plasma-discharging step,
ozone gas may be applied to an organic film pattern while being
heated, in order to enhance a process rate. However, since an
organic film pattern is heat-cured, and hence, much alterated so as
not to be separated by wet-etching, the step of applying ozone gas
to an organic film pattern is scarcely used.
[0644] A second type of ashing is a plasma-discharging step. A
plasma-discharging step is grouped further into types one and two
in dependence on how discharge is generated.
[0645] A type one is an isotropic plasma-discharging step to be
carried out under a high pressure with low power, and a type two is
an anisotropic plasma-discharging step to be carried out under a
low pressure with high power.
[0646] Both of the type one and two have a process speed higher
than that of the first type of ashing, that is, a step other than
plasma-discharging steps.
[0647] The type two has a higher process speed than the same of the
type one.
[0648] Thus, since the type one and two have a high process speed,
an organic film pattern or an underlying film can be changed with
respect to its surface condition in a short period of time. For
instance, wettability of an organic film pattern or an underlying
film can be enhanced in a short period of time. In addition, the
type one and two can be carried out for removal of an alterated
layer formed on a surface of an organic film pattern, or a
high-speed process such as dry peeling-off.
[0649] However, the second type of ashing, that is, a
plasma-discharging step exerts more damage to an object than the
first type of ashing.
[0650] In particular, an alterated layer formed on an organic film
pattern cannot be sufficiently removed by the first type of
ashing.
[0651] An anisotropic plasma-discharging step (type two) can
sufficiently remove an initially formed alterated layer, but would
exert much damage to an organic film pattern, and resultingly, an
alterated layer is newly formed on the organic film pattern.
Accordingly, it is meaningless to select an anisotropic
plasma-discharging step (type two) for removing an alterated layer
formed on a surface of an organic film pattern.
[0652] Thus, an isotropic plasma-discharging step (type one) is
usually selected for removing an alterated layer formed on a
surface of an organic film pattern.
[0653] However, in the method suggested in the above-mentioned
Japanese Patent Application Publication No. 2002-334830, when an
alterated layer formed on a surface of an organic film pattern is
removed for uniformizing a step of causing chemical (for instance,
organic solvent) to percolate into an organic film pattern for
deforming the organic film pattern, it would be impossible to
completely remove the alterated layer even by the anisotropic
plasma-discharging step (type two) or the isotropic
plasma-discharging step (type one), and it would be also impossible
to prevent a small alterated layer from being formed on an organic
film pattern due to damage newly exerted by the anisotropic and
isotropic plasma-discharging step.
[0654] The inventor found out the problem that even such a small
alterated layer newly formed due to the plasma-discharging step
prevents uniformity of a step of causing chemical solution to
percolate into an organic film pattern for deforming the organic
film pattern.
[0655] That is, the method suggested in the above-mentioned
Publication is accompanied with a problem that since uniformity in
the fusion/deformation step is insufficient as a result that the
organic film pattern is damaged by a plasma-discharging step and
that a small alterated film is newly formed on the organic film
pattern, a step of etching an underlying film to be carried out
subsequently to the fusion/deformation step is insufficiently
carried out.
[0656] The methods in accordance with First to Third Examples
provide a solution to the above-mentioned problems, ensuring that a
substrate and therefore an organic film pattern is prevented from
being damaged.
[0657] Hereinbelow is explained a related method of reducing a
number of steps in fabrication of a thin film transistor (TFT) in a
liquid crystal display device by means of the fusion/deformation
reflow step.
[0658] FIGS. 18A to 18G are plan and cross-sectional views of a
thin film transistor (TFT) device in each of steps of a related
method of fabricating a TFT substrate (not illustrated).
[0659] First, as illustrated in FIG. 18A, a gate wire 1001 is
formed on a glass substrate.
[0660] Then, an interlayer insulating film 1002 is formed so as to
cover the gate wire 1001 therewith. For instance, the interlayer
insulating film 1002 is comprised of a silicon oxide film
(SiO.sub.2) and/or a silicon nitride film (SiNx).
[0661] Then, a semiconductor film 1003 comprised of an amorphous
silicon (a-Si) layer and an ohmic contact (n+a-Si) layer, and a
metal film 1004 for a drain are formed on the interlayer insulating
film 1002.
[0662] The ohmic contact layer is comprised of a n-type amorphous
silicon (n+a-Si) layer into which impurity of phosphorus is
doped.
[0663] Then, an organic film (for instance, a resist film) is
formed on the metal film 1004.
[0664] Then, the organic film is patterned by exposing the organic
film to light through the use of a mask (specifically, a half-tone
mask), and developing the organic film. Hereinbelow, the thus
patterned organic film is referred to as a resist pattern 1005. The
resist pattern 1005 has portions having two different
thicknesses.
[0665] Then, as illustrated in FIG. 18B, an underlying film
situated below the resist pattern 1005, that is, the metal film
1004 is etched with the resist pattern 1005 being used as a
mask.
[0666] By being etched, the metal film 1004 is turned into
source/drain electrodes and source/drain wirings.
[0667] Then, as illustrated in FIG. 18C, at least a part of the
resist pattern 1005 is removed by the second removal step or a
combination of the first and second removal steps.
[0668] A thinner portion of the resist pattern 1005 is removed
among the two portions of the resist pattern 1005 having two
different thicknesses.
[0669] The first and second removal steps are carried out similarly
to the first and second removal steps carried out in Third Example
except that the second removal step is comprised principally of a
step developing an organic film pattern through the use of chemical
solution having a function of developing the organic film
pattern.
[0670] Then, as illustrated in FIG. 18D, a fusion/deformation step
(fusion/deformation reflow) is carried out to the resist pattern
1005.
[0671] The fusion/deformation step is comprised of the
gas-atmosphere applying step S3 having been referred to in the
First Example.
[0672] By carrying out the fusion/deformation step, as illustrated
in FIG. 18D, a resist mask for a source electrode and a resist mask
for a drain electrode are latitudinally reflowed to join with each
other. Thus, there is formed a joint resist mask 1006.
[0673] Then, as illustrated in FIG. 18E, the semiconductor film
1003 comprised of the amorphous silicon (a-Si) layer and the ohmic
contact (n+a-Si) layer is etched into a semiconductor island 1007
through the use of the joint resist mask 1006, and further through
the use of electrodes for source and drain and wirings for source
and drain as a mask.
[0674] Then, as illustrated in FIG. 18F, the joint resist mask 1006
is separated from the semiconductor island 1007 for removal.
[0675] Then, as illustrated in FIG. 18G, a channel etching is
carried out such that at least the ohmic contact (n+a-Si) layer is
removed between a source and a drain among the amorphous silicon
(a-Si) layer and the ohmic contact (n+a-Si) layer, with the
electrodes for source and drain and the wirings for source and
drain both being as a mask, and the at least a part of the
amorphous silicon (a-Si) layer remains as it is.
[0676] Hereinafter, a passivation film comprised of an electrically
insulating film (generally, a plasma-nitrided silicon film) is
formed. Contact holes are formed above the source and drain
electrodes. Then, there are formed a pixel electrode which
electrically connects to a source electrode at a bottom of the
contact hole, and a terminal electrode which electrically connects
to a drain electrode at a bottom of the contact hole.
[0677] A TFT substrate is fabricated in accordance with the
above-mentioned steps. Then, an opposing substrate is arranged in
facing relation with the semiconductor island of the TFT substrate.
A space formed between the TFT substrate and the opposing substrate
is filled with liquid crystal. Thus, there is fabricated a liquid
crystal display device.
Fourth Example
[0678] Hereinbelow is explained, as Fourth Example, a method of
fabricating a TFT substrate used for a liquid crystal display
device, including the fusion/deformation reflow step and the step
of removing a part of the fused/deformed organic film pattern.
[0679] FIGS. 19A to 19G are plan and cross-sectional views of a
thin film transistor (TFT) device in a method of fabricating a TFT
substrate, in accordance with Fourth Example. In the method, an
organic film is exposed to light through a half-tone mask.
[0680] First, as illustrated in FIG. 19A, a gate wire 2001 is
formed on a glass substrate (not illustrated).
[0681] Then, an interlayer insulating film 2002 is formed so as to
cover the gate wire 2001 therewith. For instance, the interlayer
insulating film 2002 is comprised of a silicon oxide film
(SiO.sub.2) and/or a silicon nitride film (SiNx).
[0682] Then, a semiconductor film 2003 comprised of an amorphous
silicon (a-Si) layer and an ohmic contact (n+a-Si) layer, and a
metal film 2004 for a drain are formed on the interlayer insulating
film 2002.
[0683] The ohmic contact layer is comprised of a n-type amorphous
silicon (n+a-Si) layer into which impurity of phosphorus is
doped.
[0684] Then, an organic film (for instance, a resist film) is
formed on the metal film 2004.
[0685] Then, the organic film is patterned by exposing the organic
film to light through the use of a mask (specifically, a half-tone
mask), and developing the organic film. Hereinbelow, the thus
patterned organic film is referred to as a resist pattern. The
resist pattern 2005 has portions having two different
thicknesses.
[0686] Then, as illustrated in FIG. 19B, an underlying film
situated below the resist pattern 2005, that is, the metal film
2004 is etched with the resist pattern 2005 being used as a
mask.
[0687] By being etched, the metal film 2004 is turned into
source/drain electrodes and source/drain wirings.
[0688] Then, as illustrated in FIG. 19C, the fusion/deformation
(fusion/deformation reflow) step is carried out to the resist
pattern 2005.
[0689] The fusion/deformation step is comprised of the
gas-atmosphere applying step S3 having been referred to in First
Example.
[0690] By carrying out the fusion/deformation step, as illustrated
in FIG. 19C, a resist mask for a source electrode and a resist mask
for a drain electrode are latitudinally reflowed to join with each
other. Namely, there is formed a joint resist mask 2006.
[0691] If necessary, the first removal step may be carried out
prior to the fusion/deformation step, in which case, the first
removal step is carried out similarly to the first removal step
carried out in Second Example.
[0692] The first removal step is carried out for the purpose of
removing an alterated or deposited layer formed on or around the
resist pattern 2005.
[0693] Then, as illustrated in FIG. 19D, at least a part of the
resist pattern 2005 is removed by the second removal step or a
combination of the first and second removal steps.
[0694] A thinner portion of the resist pattern 2005 is removed
among the two portions of the resist pattern 2005 having two
different thicknesses.
[0695] The first and second removal steps are carried out similarly
to the first and second removal steps carried out in Third Example.
The second removal step is comprised principally of a step of
developing an organic film through the use of a developing
agent.
[0696] By carrying out the first and second removal steps, a
portion of the resist pattern 2005 having an area having increased
due to the fusion/deformation reflow, that is, an unnecessary
portion of the resist pattern 2005 is removed, ensuring that the
resist pattern 2005 is accurately patterned into a target
pattern.
[0697] Then, as illustrated in FIG. 19E, the semiconductor film
2003 comprised of the amorphous silicon (a-Si) layer and the ohmic
contact (n+a-Si) layer is etched into a semiconductor island 2007
through the use of the joint resist mask 2006 and further through
the use of electrodes for source and drain and wirings for source
and drain as a mask.
[0698] Then, as illustrated in FIG. 19F, the joint resist mask 2006
is separated from the semiconductor island 2007 for removal.
[0699] Then, as illustrated in FIG. 19G, a channel etching is
carried out such that at least the ohmic contact (n+a-Si) layer is
removed between a source and a drain among the amorphous silicon
(a-Si) layer and the ohmic contact (n+a-Si) layer, with the
electrodes for source and drain and the wirings for source and
drain both being as a mask, and the at least a part of the
amorphous silicon (a-Si) layer remains as it is.
[0700] Hereinafter, a passivation film comprised of an electrically
insulating film (generally, a plasma-nitrided silicon film) is
formed. Contact holes are formed above the source and drain
electrodes. Then, there are formed a pixel electrode which
electrically connects to a source electrode at a bottom of the
contact hole, and a terminal electrode which electrically connects
to a drain electrode at a bottom of the contact hole.
[0701] A TFT substrate is fabricated in accordance with the
above-mentioned steps. Then, an opposing substrate is arranged in
facing relation with the semiconductor island of the TFT substrate.
A space formed between the TFT substrate and the opposing substrate
is filled with liquid crystal. Thus, there is fabricated a liquid
crystal display device.
[0702] The channel etching may be carried out after the step of
etching the metal film 2004 through the use of the resist pattern
2005 as a mask, illustrated in FIG. 19B, in which case, it is
preferable that at least a part of the amorphous silicon (a-Si)
layer in a channel area having been contaminated or alterated is
etched or surface-treated after the joint resist mask 2006 was
separated from the semiconductor island 2007 for removal (FIG.
19F). However, it is necessary to remain most of the amorphous
silicon (a-Si) layer non-etched or as it is.
Fifth Example
[0703] Hereinbelow is explained, as Fifth Example, an example of a
method of reducing a number of steps in fabrication of a TFT
substrate used for a liquid crystal display device, including the
fusion/deformation reflow step and the step of removing a part of
the fused/deformed organic film pattern.
[0704] FIGS. 20A to 20G are plan and cross-sectional views of a
thin film transistor (TFT) device in a method of reducing a number
of steps in fabrication of a TFT substrate used for a liquid
crystal display device, in accordance with the Fifth
Embodiment.
[0705] Whereas a half-tone mask was used in Fourth Example, a
half-tone mask is not used, but an ordinary mask is used in Fifth
Example.
[0706] First, as illustrated in FIG. 20A, a gate wire 3001 is
formed on a glass substrate (not illustrated).
[0707] Then, an interlayer insulating film 3002 is formed so as to
cover the gate wire 3001 therewith. For instance, the interlayer
insulating film 3002 is comprised of a silicon oxide film
(SiO.sub.2) and/or a silicon nitride film (SiNx).
[0708] Then, a semiconductor film 3003 comprised of an amorphous
silicon (a-Si) layer and an ohmic contact (n+a-Si) layer, and a
metal film 3004 for a drain are formed on the interlayer insulating
film 3002.
[0709] The ohmic contact layer is comprised of a n-type amorphous
silicon (n+a-Si) layer into which impurity of phosphorus is
doped.
[0710] Then, an organic film (for instance, a resist film) is
formed on the metal film 3004.
[0711] Then, the organic film is patterned by exposing the organic
film to light through the use of a mask (specifically, not a
half-tone mask, but a standard mask), and developing the organic
film. Hereinbelow, the thus patterned organic film is referred to
as a resist pattern. The resist pattern 3005 has portions having
two different thicknesses.
[0712] Then, as illustrated in FIG. 20B, an underlying film
situated below the resist pattern 3005, that is, the metal film
3004 is etched with the resist pattern 3005 being used as a
mask.
[0713] By being etched, the metal film 3004 is turned into
source/drain electrodes and source/drain wirings.
[0714] Then, as illustrated in FIG. 20C, the fusion/deformation
(fusion/deformation reflow) step is carried out to the resist
pattern 3005.
[0715] The fusion/deformation step is comprised of the
gas-atmosphere applying step S3 having been referred to in First
Example.
[0716] By carrying out the fusion/deformation step, as illustrated
in FIG. 20C, a resist mask for a source electrode and a resist mask
for a drain electrode are latitudinally reflowed to join with each
other. Namely, there is formed a joint resist mask 3006.
[0717] If necessary, the first removal step may be carried out
prior to the fusion/deformation step, in which case, the first
removal step is carried out similarly to the first removal step
carried out in Second Example.
[0718] The first removal step is carried out for the purpose of
removing an alterated or deposited layer formed on or around the
resist pattern 3005.
[0719] Then, as illustrated in FIG. 20D, at least a part of the
resist pattern 3005 is removed by the second removal step or a
combination of the first and second removal steps.
[0720] A thinner portion of the resist pattern 3005 is removed
among the two portions of the resist pattern 3005 having two
different thicknesses.
[0721] The first and second removal steps are carried out similarly
to the first and second removal steps carried out in Third Example.
The second removal step herein is comprised principally of a step
of developing the resist pattern 3005 through the use of a
developing agent.
[0722] By carrying out the first and second removal steps, a
portion of the joint resist mask 3006 having an area having
increased due to the fusion/deformation reflow, that is, an
unnecessary portion of the joint resist mask 3006 is removed,
ensuring that the resist pattern 3005 is accurately patterned into
a target pattern.
[0723] Then, as illustrated in FIG. 20E, the semiconductor film
3003 comprised of the amorphous silicon (a-Si) layer and the ohmic
contact (n+a-Si) layer is etched into a semiconductor island 3007
through the use of the joint resist mask 3006 and further through
the use of electrodes for source and drain and wirings for source
and drain as a mask.
[0724] Then, as illustrated in FIG. 20F, the joint resist mask 3006
is separated from the joint resist mask 3006 for removal.
[0725] Then, as illustrated in FIG. 20G, a channel etching is
carried out such that at least the ohmic contact (n+a-Si) layer is
removed between a source and a drain among the amorphous silicon
(a-Si) layer and the ohmic contact (n+a-Si) layer, with the
electrodes for source and drain and the wirings for source and
drain both being as a mask, and the at least a part of the
amorphous silicon (a-Si) layer remains as it is.
[0726] Hereinafter, a passivation film comprised of an electrically
insulating film (generally, a plasma-nitrided silicon film) is
formed. Contact holes are formed above the source and drain
electrodes. Then, there are formed a pixel electrode which
electrically connects to a source electrode at a bottom of the
contact hole, and a terminal electrode which electrically connects
to a drain electrode at a bottom of the contact hole.
[0727] A TFT substrate is fabricated in accordance with the
above-mentioned steps. Then, an opposing substrate is arranged in
facing relation with the semiconductor island of the TFT substrate.
A space formed between the TFT substrate and the opposing substrate
is filled with liquid crystal. Thus, there is fabricated a liquid
crystal display device.
[0728] The channel etching may be carried out after the step of
etching the metal film 3004 through the use of the resist pattern
3005, illustrated in FIG. 20B, in which case, at least a part of
the amorphous silicon (a-Si) layer in a channel area having been
contaminated or alterated is etched or surface-treated even after
the joint resist mask 3006 was separated from the semiconductor
island 3007 for removal. However, it is necessary to remain most of
the amorphous silicon (a-Si) layer non-etched or as it is.
[0729] In Fourth and Fifth Examples, the gate electrode, the source
electrode, the drain electrode and the metal film of the thin film
transistor (TFT) may be comprised of any one of the following
layers or structures:
[0730] (a) a single layer composed of aluminum or aluminum
alloy;
[0731] (b) a single layer composed of chromium or chromium
alloy;
[0732] (c) a two-layered structure including a layer composed of
aluminum or aluminum alloy and a layer composed of chromium or
chromium alloy;
[0733] (d) a two-layered structure including a layer composed of
aluminum or aluminum alloy and a layer composed of titanium or
titanium alloy;
[0734] (e) a two-layered structure including a layer composed of
aluminum or aluminum alloy and a layer composed of titanium nitride
or titanium nitride alloy;
[0735] (f) a two-layered structure including a layer composed of
aluminum or aluminum alloy and a layer composed of molybdenum or
molybdenum alloy;
[0736] (g) a two-layered structure including a layer composed of
chromium or chromium alloy and a layer composed of molybdenum or
molybdenum alloy;
[0737] (h) a three-layered structure including a layer composed of
chromium or chromium alloy, a layer composed of molybdenum or
molybdenum alloy, and a layer composed of chromium or chromium
alloy;
[0738] (i) a three-layered structure including a layer composed of
molybdenum or molybdenum alloy, a layer composed of aluminum or
aluminum alloy, and a layer composed of molybdenum or molybdenum
alloy;
[0739] (j) a three-layered structure including a layer composed of
aluminum or aluminum alloy, a layer composed of molybdenum or
molybdenum alloy, and a layer composed of chromium or chromium
alloy;
[0740] (k) a three-layered structure including a layer composed of
aluminum or aluminum alloy, a layer composed of molybdenum or
molybdenum alloy, and a layer composed of titanium or titanium
alloy; and
[0741] (l) a three-layered structure including a layer composed of
aluminum or aluminum alloy, a layer composed of titanium nitride or
titanium nitride alloy, and a layer composed of titanium or
titanium alloy.
[0742] In the above-mentioned Examples, a TFT substrate is designed
to include a glass substrate, but may be designed to include an
electrically insulating substrate other than a glass substrate.
[0743] The above-mentioned Examples relate to a method of
fabricating a pattern of a stagger type TFT. The method may be
applied, as well as a method of fabricating a pattern of a stagger
type TFT, to a method of fabricating a TFT pattern including a step
of forming either a color filter layer or a planarized layer and a
color filter layer below a pixel electrode.
[0744] The above-mentioned Examples are applied to a vertical
electric field drive type liquid crystal display device. It should
be noted that the above-mentioned Examples may be applied to a
horizontal electric field drive type liquid crystal display device
such as an in-plane switching (IPS) type liquid crystal display
device.
[0745] The methods in accordance with Fourth and Fifth Examples may
be included in a method of fabricating a TFT. As an example of a
TFT substrate, there is a TFT substrate used for a liquid crystal
display device.
[0746] A color filter including an electrically insulating film, a
color (RGB: red, green and blue) filter layer, a black matrix
layer, and a transparent electrode, or a monochromatic filter is
fabricated, and then, a pixel electrode composed of ITO, and an
alignment film and other parts are formed on the TFT substrate.
Then, liquid crystal is sandwiched between the TFT substrate and
the opposing substrate in a hermetically sealed condition. Then, a
polarizing filter is attached to each of the substrates. Thus,
there is completed a liquid crystal display device.
[0747] It is possible to control a thickness of a part of a resist
mask as follows.
[0748] First, there is fabricated a reticle to be used in a step of
exposing a resist film to light. The reticle has a mask pattern
including a light-impermeable part, and light-permeable parts
allowing light to pass therethrough in different degrees. The
light-impermeable part and the light-permeable parts are
transferred to a resist film to thereby form the above-mentioned
resist mask.
[0749] As an alternative, two or more reticle masks are used in a
step of exposing a resist film to light. An amount of light to
which a resist film is exposed is changed in two steps, thereby the
above-mentioned resist mask being fabricated.
[0750] In the above-mentioned method, a half-tone mask was used to
form a resist pattern for controlling a thickness of portions of
the resist mask. The half-tone mask is comprised of a reticle
having a light-impermeable portion not allowing light to pass
therethrough, and a portion allowing half of light to pass
therethrough.
[0751] Hereinbelow are explained examples of a method of forming a
reticle.
Example 1
[0752] In Example 1, a light-impermeable portion not allowing light
to pass therethrough, and a half-transmission portion allowing half
of light to pass therethrough are formed on a reticle
substrate.
[0753] The portions are composed of chromium, for instance.
[0754] The half-transmission portion has a pattern composed of
chromium and having a resolution equal to or smaller than maximum
exposure resolution. For instance, the half-transmission portion
has rectangular patterns arranged at a predetermined pitch, each
pattern having a width equal to or smaller than exposure
wavelength. As an alternative, the half-transmission portion has
such rectangular patterns arranged in a grid.
[0755] In Example 1, light transmission of irradiated light for
exposure is set in the range of 20 to 80% in the half-transmission
portion, that is, in an area in which the above-mentioned chromium
pattern having a resolution equal to or smaller than maximum
exposure resolution is formed.
Example 2
[0756] In Example 2, a light-impermeable portion not allowing light
to pass therethrough is formed on a reticle substrate in a
predetermined pattern. The light-impermeable portion is composed of
chromium. Chromium is etched into a thin film portion.
[0757] In an area in which the thin film portion composed of
chromium is formed, that is, in a half-transmission portion, light
transmission of irradiated light for exposure is set about 50%.
Example 3
[0758] In Example 3, a light-impermeable portion not allowing light
to pass therethrough is formed on a reticle substrate in a
predetermined pattern. The light-impermeable portion is composed of
chromium. A half-transmission portion in Example 3 is comprised of
a half-tone portion.
[0759] The half-tone portion is composed of tungsten silicide or
molybdenum silicide, for instance.
[0760] Hereinbelow is explained a policy as to selection of the
removal step to be carried out for removing an alterated or
deposited layer formed at a surface of an organic film pattern in
each of the above-mentioned First, Second and Third Examples.
[0761] FIG. 12 illustrates a degree of alteration of an alterated
layer in dependence on causes by which the alterated layer is
formed. In FIG. 12, a degree of alteration is determined in
accordance with difficulty in peeling off an alterated layer with a
wet step.
[0762] As illustrated in FIG. 12, a degree of alteration of an
alterated layer depends highly on a chemical to be used in
wet-etching, whether dry-etching is isotropic or anisotropic,
whether deposition exists on an organic film pattern, and gas used
in dry-etching. Hence, difficulty in removing an alterated layer
depends also on those.
[0763] As chemical solution used in the chemical-solution applying
step of applying chemical solution to an organic film pattern,
there is selected acid solution, alkaline solution or organic
solvent alone or in combination.
[0764] Specifically, as the chemical solution is selected alkaline
aqueous solution or aqueous solution containing at least one amine
as organic solvent in the range of 0.01 to 10 weight % both
inclusive.
[0765] Herein, amine is selected from monoethyl amine, diethyl
amine, triethyl amine, monoisopyl amine, diisopyl amine, triisoply
amine, monobutyl amine, dibutyl amine, tributyl amine,
hydroxylamine, diethylhydroxylamine, diethylhydroxylamine
anhydride, pyridine, or picoline.
[0766] If a degree of alteration of an alterated layer is
relatively low, that is, if an alterated layer is formed due to
oxidation caused by being aged, acid etchant or isotropic oxygen
(O.sub.2) ashing, the selected chemical solution may contain amine
in the range of 0.05 to 5 weight % both inclusive, for
instance.
[0767] FIG. 17 is a graph showing relation between a concentration
of amine in chemical solution and a removal rate, in association
with whether an organic film pattern is alterated or not.
[0768] As illustrated in FIG. 17, it is preferable that the
chemical solution contains amine as organic solvent in the range of
0.05 to 2.0 weight % both inclusive in order to remove only an
alterated layer and remain a non-alterated portion of an organic
film pattern.
[0769] To this end, it is preferable to select hydroxylamine,
diethylhydroxyl amine, diethylhydroxylamine anhydride, pyridine, or
picoline to be contained in the chemical solution.
[0770] It is preferable that the chemical solution contains
anticorrosive. As anticorrosive, there may be selected D-glucose
(C.sub.6H.sub.12O.sub.6), chelate or antioxidant.
[0771] By setting a suitable period of time for carrying out the
step of applying chemical solution to an organic film pattern, as
well as selecting suitable chemical solution, it would be possible
to remove only an alterated or deposited layer, remain a
non-alterated portion of an organic film pattern, or allow an
organic film pattern having been covered with a deposited layer, to
appear.
[0772] The chemical-solution applying step of applying chemical
solution to an organic film pattern provides an advantage that
organic solvent is likely to penetrate an organic film pattern in a
fusion/deformation step to be carried out subsequently thereto.
[0773] Actually, by applying the above-mentioned chemical to an
organic film pattern at a surface thereof, an alterated layer is
cracked, or a part or all of an alterated layer is removed. Thus,
it would be possible to avoid organic solvent from being prevented
by an altered layer from penetrating an organic film pattern in a
fusion/deformation step such as the step of applying gas atmosphere
to an organic film pattern.
[0774] What is important is that a non-alterated portion of an
organic film pattern should not be removed, but remain, and that
organic solvent can readily penetrate a non-alterated portion of an
organic film pattern by removing only an alterated layer or by
cracking an alterated layer. It is necessary to select chemical
solution allowing to do so.
[0775] As illustrated in FIGS. 2B, 2C, 3B, 3C, 4B and 4D, it is
preferable that the ashing step is carried out prior to the step of
applying chemical solution to an organic film pattern, when an
alterated or deposited layer is firm or thick, or is quite
difficult to remove, because the organic film pattern is combined
with fluorine.
[0776] A combination of the ashing step and the step of applying
chemical solution to an organic film pattern solves a problem that
it is quite difficult to remove an alterated layer only by carrying
out the step of applying chemical solution to an organic film
pattern, or it takes much time to do the same.
[0777] FIG. 13 illustrates variation of an alterated layer to which
only an oxygen (O.sub.2) ashing step or an isotropic plasma step is
applied, FIG. 14 illustrates variation of an alterated layer to
which only a step of applying chemical solution (aqueous solution
containing hydroxylamine at 2%) is applied, and FIG. 15 illustrates
variation of an alterated layer to which both the above-mentioned
ashing step and the above-mentioned step of applying chemical
solution are applied in this order.
[0778] In FIGS. 13 to 15, similarly to FIG. 12, a degree of
alteration is determined in accordance with difficulty in peeling
off an alterated layer with a wet step.
[0779] As illustrated in FIGS. 13 to 15, an alterated layer can be
removed by carrying out any step(s). However, comparing the oxygen
ashing step (isotropic plasma step) illustrated in FIG. 13 with the
step of applying chemical solution (aqueous solution containing
hydroxylamine at 2%) to an alterated layer, illustrated in FIG. 14,
a degree of removal of an alterated layer is different from each
other in accordance with a thickness and characteristic of an
alterated layer.
[0780] The oxygen ashing step (isotropic plasma step) is effective
to removal of an alterated layer having deposition thereon, as
illustrated in FIG. 13, but is likely to damage an object. Hence,
if the oxygen ashing step (isotropic plasma step) is carried out to
an alterated layer having no deposition thereon, an alterated layer
remains without being removed, to a higher degree than a degree at
which an alterated layer is removed only by the step of applying
chemical solution to an alterated layer (FIG. 14).
[0781] In contrast, the step of applying chemical (aqueous solution
containing hydroxylamine at 2%) to an alterated layer is less
effective than the oxygen ashing step to removal of an alterated
layer having deposition thereon, as illustrated in FIG. 14, but
does not damage an object. Hence, if the step of applying chemical
to an alterated layer is carried out to an alterated layer having
no deposition thereon, an alterated layer remains without being
removed to a higher degree than a degree at which an alterated
layer is removed only by the oxygen ashing (isotropic plasma) step
(FIG. 13).
[0782] Thus, in order to have the merits shown in FIGS. 13 and 14,
the oxygen ashing step (isotropic plasma step) and the step of
applying chemical (aqueous solution containing hydroxylamine at 2%)
to an alterated layer are carried out in this order, as illustrated
in FIG. 15.
[0783] It is understood that the method shown in FIG. 15 is
effective to both an alterated layer having deposition thereon and
an alterated layer having no deposition thereon, and can remove an
alterated layer without damage remaining.
[0784] It is preferable that a layer lying below an organic film
pattern is treated at a surface thereof for enhancing wettability
thereof, in order to uniformize a fusion/deformation step such as a
step of applying gas atmosphere to an organic film pattern.
[0785] For instance, wettability of an underlying film can be
enhanced by carrying out the above-mentioned ashing step, that is,
the oxygen (O.sub.2) plasma step or UV ozone treatment.
[0786] For instance, the oxygen plasma step is carried out under
the following conditions.
[0787] Flow rate of O.sub.2: 300 sccm
[0788] Pressure: 100 Pa
[0789] RF power: 1000 W
[0790] Time: 120 seconds
[0791] The UV ozone treatment is carried out by radiating
ultra-violet rays to an underlying film in ozone gas atmosphere
with a temperature of a substrate being kept in the range of 100 to
200 degrees centigrade, for instance.
[0792] Wettability of an underlying film can be enhanced also by
various plasma-discharge steps such as fluorine gas plasma
(SF.sub.6 gas plasma, CF.sub.4 gas plasma, CHF.sub.3 gas plasma,
etc.) or fluorine/oxygen gas plasma (SF.sub.6/O.sub.2 gas plasma,
CF.sub.4/O.sub.2 gas plasma, CHF.sub.3/O.sub.2 gas plasma,
etc.).
[0793] These plasma steps improve wettability of a surface of an
underlying film not covered with an organic film pattern.
[0794] Accordingly, by carrying out these plasma steps, an organic
film pattern deformed by a fusion/deformation step (for instance,
the step of applying gas atmosphere to an organic film pattern) can
readily reflow at a surface of an underlying film.
[0795] Pre-steps such as various plasma steps, oxygen plasma step
or UV ozone step tend to damage an object in comparison with the
above-mentioned step of applying chemical solution to an alterated
layer. Hence, by removing an alterated layer by applying chemical
solution to the alterated layer subsequently to such pre-steps as
mentioned above, it would be possible to enhance wettability of an
underlying film and remove an alterated layer formed at a surface
of an organic film pattern, without damaging an organic film
pattern. This ensures uniformly carrying out a fusion/deformation
step.
[0796] FIG. 16 illustrates comparison between the removal steps in
the above-mentioned Examples and the related method, both to be
carried out prior to a fusion/deformation step (for instance, a
gas-atmosphere applying step of applying gas atmosphere to an
organic film pattern).
[0797] FIG. 16(A) illustrates that an organic film pattern 32 is
formed on a substrate 31.
[0798] FIG. 16(B) illustrates that an underlying film (for
instance, an upper portion 31a of the substrate 31) is patterned by
etching with the organic film pattern 32 being used as a mask.
[0799] FIG. 16(C) is an enlarged view of the organic film pattern
32 illustrated in FIG. 16(B).
[0800] As illustrated in FIG. 16(C), an alterated layer 32a is
formed at a surface of the organic film pattern 32, due to the
etching. Hence, a non-alterated portion 32b of the organic film
pattern 32 is covered with the alterated layer 32a.
[0801] FIG. 16(D) illustrates the organic film pattern 32 to which
the removal step (for instance, the chemical-solution applying step
of applying chemical solution to an organic film pattern) is
applied.
[0802] As illustrated in FIG. 16(D), as a result of carrying out
the removal step, the alterated layer 32a is removed. The organic
film pattern 32 is not damaged.
[0803] FIG. 16(E) illustrates the organic film pattern 32 to which
a fusion/deformation step was applied subsequently to the removal
step illustrated in FIG. 16(D).
[0804] As illustrated in FIG. 16(E), the organic film pattern 32 is
uniformly deformed by the fusion/deformation step.
[0805] FIG. 16(F) illustrates the organic film pattern 32 to which
the related removal step (only ashing step) is applied.
[0806] As illustrated in FIG. 16(F), though the alterated layer 32a
is removed even by the related removal step, the organic film
pattern 32 remains damaged.
[0807] FIG. 16(G) illustrates the organic film pattern 32 to which
a fusion/deformation step is applied subsequently to the related
removal step illustrated in FIG. 16(F).
[0808] As illustrated in FIG. 16(G), the organic film pattern 32
may be uniformly deformed by the fusion/deformation step in
accordance with a degree of damage exerted on the organic film
pattern 32. However, if the organic film pattern 32 was much
damaged, the organic film pattern would be non-uniformly deformed,
or the organic film pattern 32 would be fused. Thus, it is
difficult to suitably carry out the fusion/deformation step.
[0809] The apparatus for processing a substrate is comprised of a
substrate carrier for carrying a substrate, a processing unit or
processing units selected among the following processing units (a)
to (h), and a controller for operating the processing units in
accordance with an order in which the steps of the method of
processing a substrate are carried out:
[0810] (a) a substrate-temperature controlling unit 19 for
controlling a temperature of a substrate and hence an organic film
pattern;
[0811] (b) a gas-atmosphere applying unit 22 for applying gas
atmosphere to an organic film pattern;
[0812] (c) a heating unit 18 for heating a substrate and hence an
organic film pattern;
[0813] (d) a chemical-solution applying unit 21 for carrying out
the first, second or third chemical-solution applying step;
[0814] (e) a developing unit 20 used when the first, second or
third chemical-solution applying step is comprised of a developing
step;
[0815] (f) an ashing unit 23 for ashing an organic film
pattern;
[0816] (g) a light-exposure unit 17 for exposing an organic film
pattern to light; and
[0817] (h) a back light-exposure unit 19 for exposing an organic
film pattern to light through a lower surface of a substrate.
[0818] The heating unit 18 and the substrate-temperature
controlling unit 19 can control a broad range of a temperature.
Hence, if both a range of a temperature controlled by the heating
unit 18 and a range of a temperature controlled by the
substrate-temperature controlling unit 19 are within a range of a
temperature controlled by a certain processing unit, the processing
unit can carry out both a substrate-temperature controlling step to
be carried out by the substrate-temperature controlling unit 19 and
a heating step to be carried out by the heating step 18, by
changing a temperature range in accordance with either step to be
carried out.
[0819] If a method of processing a substrate includes a plurality
of common steps, the common steps may be carried out in a single
processing unit. As an alternative, in order to enhance a
processing yield, the common steps may be carried out in parallel
in a plurality of processing units, in which case, a controller
memorizing steps of the method controls an order in which steps of
the method are carried out.
[0820] The methods in accordance with Fourth and Fifth Examples may
be applied to, for instance, a liquid crystal display (LCD) device
having a flat display panel, an electroluminescence (EL) display
device, a field emission display (FED), a fluorescence display
device, an active device in a plasma display panel (PDP), or a
substrate including an integrated circuit.
[0821] In the fourth and fifth embodiments, the present invention
is applied to a substrate. It should be noted that the present
invention may be applied to a method of fabricating a liquid
crystal display device (a vertical electric field type liquid
crystal display device, a horizontal electric field type liquid
crystal display device, a light-transmission type liquid crystal
display device, a light-reflection type liquid crystal display
device, and a half-transmission type liquid crystal display
device), and a display device such as an EL display device, or a
method of fabricating other semiconductor devices.
INDUSTRIAL APPLICABILITY
[0822] A method of processing a substrate and chemical solution to
be used in the method, in accordance with the above-mentioned
Examples, are applied to a substrate. However, it should be noted
that the above-mentioned Examples may be applied to a method of
fabricating a liquid crystal display device (a vertical electric
field type liquid crystal display device, a horizontal electric
field type liquid crystal display device, a light-transmission type
liquid crystal display device, a light-reflection type liquid
crystal display device, and a half-transmission type liquid crystal
display device), and a display device such as an
electroluminescence (EL) display device, or a method of fabricating
other semiconductor devices.
[0823] Though the above-mentioned Examples have been explained as a
method of processing a substrate such as a semiconductor substrate
or a liquid crystal substrate. It should be noted that Examples may
be applied to:
[0824] (a) a method of and an apparatus for fabricating a device
including a substrate processed in accordance with the
above-mentioned method or apparatus for processing a substrate;
[0825] (b) a method of and an apparatus for fabricating a display
device;
[0826] (c) a method of and an apparatus for fabricating a
semiconductor device;
[0827] (d) a method of and an apparatus for fabricating a liquid
crystal display device;
[0828] (e) a method of and an apparatus for fabricating an
electroluminescence (EL) display device;
[0829] (f) a method of and an apparatus for fabricating a field
emission display device; or
[0830] (g) a method of and an apparatus for fabricating a plasma
display device.
[0831] The exemplary advantages obtained by the above-mentioned
Examples are described hereinbelow.
[0832] A method of processing an organic film pattern formed on a
substrate, in accordance with the above-mentioned Examples,
includes, in sequence of, a fusion/deformation step of fusing and
thereby deforming the organic film pattern, and a third removal
step of removing at least a part of the fused and deformed organic
film pattern.
[0833] The method in accordance with the above-mentioned Examples
may include additionally various heating steps and various removal
steps (a removal step of removing an alterated or deposited layer
formed on a surface of an organic film pattern, or a removal step
of removing at least a part of an organic film pattern).
[0834] An organic film pattern is enlarged in an area due the
fusion/deformation step. The third removal step of removing at
least a part of the fused and deformed organic film pattern reduces
an area of the thus enlarged organic film pattern. Thus, it is
possible to enhance controllability for patterning an organic film
pattern into a desired pattern or a desired size.
[0835] The fusion/deformation step (specifically, a gas-atmosphere
applying step) was carried out also in the relate methods. The
fusion/deformation step causes an organic film pattern to deform in
the range of 5 to 20 micrometers (it is possible to deform an
organic film pattern by 100 micrometers or more).
[0836] However, since an organic film pattern is much deformed, if
the organic film pattern is required to be accurately patterned, it
would be necessary to accurately control the deformation of the
organic film pattern.
[0837] In order to reduce a number of photolithography steps, there
may be used an organic film pattern (specifically, a resist
pattern) for forming a source and a drain in a channel. The
fusion/deformation step is used for deforming two separate portions
of the resist pattern located in the vicinity of a channel,
corresponding to the source and drain, thereby unifying the
separate two portions to each other.
[0838] It is necessary to cause much "chemical solution fusion
reflow" in order to stably unify the separate two portions to each
other. However, if "chemical solution fusion reflow" is carried out
so much, a resist pattern associated with portions other than a
channel, such as wirings, would be much fused and deformed.
[0839] Accordingly, it was necessary in the related methods to
design a resist pattern to have two portions having different
thicknesses from each other, and to remove a thinner portion of the
resist pattern before carrying out the fusion/deformation step.
[0840] However, since an organic film pattern had an increased area
due to the fusion/deformation step, it was necessary to accurately
control a period of time for carrying out the fusion/deformation
step to thereby control accurately the deformation of an organic
film pattern, in order to prevent an area of the organic film
pattern from increasing.
[0841] In contrast, though the method in accordance with the
above-mentioned Examples includes the fusion/deformation step
(specifically, a gas-atmosphere applying step), the method in
accordance with the above-mentioned Examples further includes a
step of removing an unnecessary portion of the organic film pattern
(for instance, a resist pattern) having an area having been
increased more than necessary due to the fusion/deformation
reflow.
[0842] The step of removing the above-mentioned unnecessary portion
of the organic film pattern may be comprised of an ashing step and
a chemical-solution step (using chemical solution having a function
of developing an organic film pattern or a function of separating
an organic film pattern) singly or in combination.
[0843] Specifically, in the method in accordance with the
above-mentioned Examples, after the fusion/deformation step has
been carried out for fusing and thereby deforming an organic film
pattern formed on a substrate, an unnecessary portion of the
organic film pattern or a portion of the organic film pattern
having an area having increased more than necessary is at least
partially removed by various removal steps (defined as the "third
removal step" in claims).
[0844] In the related methods, an area of an organic film pattern
is only increased due to the fusion/deformation reflow, and an
increasing rate is controlled by controlling a period of time
during which the fusion/deformation reflow is carried out, for
instance. In contrast, the above-mentioned Examples make it
possible to control an area of an organic film pattern in opposite
ways. That is, the above-mentioned Examples provide the second
control to an area of an organic film pattern by removing or
contracting the organic film pattern after the fusion/deformation
reflow was carried out, ensuring that the deformation of an organic
film pattern can be accurately controlled.
[0845] In order to reduce a number of photolithography steps in the
related methods, there was used an organic film pattern
(specifically, a resist pattern) for forming a source and a drain
in a channel. The fusion/deformation step was used for deforming
two separate portions of the resist pattern located in the vicinity
of a channel, corresponding to the source and drain, thereby
unifying the separate two portions to each other.
[0846] However, if the chemical solution fusion reflow caused by
the fusion/deformation step is small, it was not possible to unify
the separate two portions of an organic film pattern to each other,
but there is less generated a portion of an organic film pattern
having an area increased more than necessary. If the chemical
solution fusion reflow caused by the fusion/deformation step is
large, there was much generated a portion of an organic film
pattern having an area increased more than necessary, but it is
possible to unify the separate two portions of an organic film
pattern to each other.
[0847] In contrast, when the method in accordance with the
above-mentioned Examples is used for reducing a number of
photolithography steps, the chemical-solution reflow is caused
sufficiently large due to the fusion/deformation step, and then, a
deformed portion of the organic film pattern is removed or
contracted in area, thereby the deformed portion of the organic
film pattern would have a desired area. Thus, the method in
accordance with the above-mentioned Examples provides only the
merits obtained in the related methods.
[0848] In the explanation made above, the above-mentioned Examples
are applied to a substrate. It should be noted that the
above-mentioned Examples may be applied to a method of fabricating
a liquid crystal display device (a vertical electric field type
liquid crystal display device, a horizontal electric field type
liquid crystal display device, a light-transmission type liquid
crystal display device, a light-reflection type liquid crystal
display device, and a half-transmission type liquid crystal display
device), and a display device such as an electroluminescence (EL)
display device, or a method of fabricating other semiconductor
devices.
[0849] While the present invention has been described in connection
with certain preferred embodiments, it is to be understood that the
subject matter encompassed by way of the present invention is not
to be limited to those specific embodiments. On the contrary, it is
intended for the subject matter of the invention to include all
alternatives, modifications and equivalents as can be included
within the spirit and scope of the following claims.
[0850] The entire disclosure of Japanese Patent Application No.
2006-147810 filed on May 29, 2006, including specification, claims,
drawings and summary is incorporated herein by reference in its
entirety.
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