U.S. patent application number 11/192042 was filed with the patent office on 2005-12-22 for plasma processing method and apparatus.
Invention is credited to Kimura, Tadashi, Okumura, Tomohiro, Saitoh, Mitsuo, Sato, Kenichi, Yashiro, Yoichiro.
Application Number | 20050279458 11/192042 |
Document ID | / |
Family ID | 27738911 |
Filed Date | 2005-12-22 |
United States Patent
Application |
20050279458 |
Kind Code |
A1 |
Okumura, Tomohiro ; et
al. |
December 22, 2005 |
Plasma processing method and apparatus
Abstract
Provided is a plasma processing method for generating
microplasma in a space of a microplasma source arranged in the
vicinity of an object to be processed by supplying gas to the space
and supplying electric power to a member located in the vicinity of
the space, making activated particles emitted from an opening of
the microplasma source joined to the space act on the object, and
forming a fine linear portion on the object. The fine linear
portion is formed on the object while flowing the gas to the
neighborhood of the opening along the lengthwise direction of the
fine linear portion parallel to the object.
Inventors: |
Okumura, Tomohiro;
(Kadoma-shi, JP) ; Kimura, Tadashi; (Kobe-shi,
JP) ; Yashiro, Yoichiro; (Kadoma-shi, JP) ;
Sato, Kenichi; (Ikoma-shi, JP) ; Saitoh, Mitsuo;
(Neyagawa-shi, JP) |
Correspondence
Address: |
WENDEROTH, LIND & PONACK, L.L.P.
2033 K STREET N. W.
SUITE 800
WASHINGTON
DC
20006-1021
US
|
Family ID: |
27738911 |
Appl. No.: |
11/192042 |
Filed: |
July 29, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
11192042 |
Jul 29, 2005 |
|
|
|
10365449 |
Feb 13, 2003 |
|
|
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Current U.S.
Class: |
156/345.47 |
Current CPC
Class: |
H01L 21/67069 20130101;
H01J 37/32376 20130101; H05H 1/2406 20130101; H01J 37/32082
20130101; H01J 37/32935 20130101 |
Class at
Publication: |
156/345.47 |
International
Class: |
C23F 001/00 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2002 |
JP |
2002-38103 |
Mar 19, 2002 |
JP |
2002-76816 |
Oct 24, 2002 |
JP |
2002-309349 |
Claims
1-15. (canceled)
16. A plasma processing apparatus comprising: a microplasma source
arranged in a vicinity of an object to be processed; a gas supply
unit for supplying plasma generating-use gas to a space of the
microplasma source; and a power supply for supplying electric power
to a member located in the vicinity of the space of the microplasma
source, the space of the microplasma source communicating with a
gas supply inlet to which the gas is supplied and a gas exhaust
outlet which is provided separately from an opening of the
microplasma source opposite to the object and from which the gas
supplied to the space is exhausted, and the fine linear portion
being formed on the object by generating microplasma in the space
of the microplasma source while flowing the gas parallel to the
object along a lengthwise direction of the fine linear portion to
be formed on the object in the vicinity of the opening from the gas
supply inlet toward the gas exhaust outlet in the space of the
microplasma source and by making activated particles discharged
from the opening of the microplasma source communicating with the
space act on the object.
17. The plasma processing apparatus as claimed in claim 16, wherein
the member located in the vicinity of the space of the microplasma
source for supplying the electric power is at least one of an
electrode provided on a side opposite from a surface to be
processed of the object, the object, and the microplasma
source.
18. The plasma processing apparatus as claimed in claim 16, wherein
a cross-sectional area obtained by cutting the space for generating
the microplasma by a plane perpendicular to the lengthwise
direction of the fine linear portion is larger than a
cross-sectional area obtained by cutting a rectangular
parallelepiped that has the opening of the microplasma source and
the fine linear portion of the object as opposite surfaces by a
plane perpendicular to the lengthwise direction of the fine linear
portion.
19. The plasma processing apparatus as claimed in claim 16, wherein
a cross-sectional area obtained by cutting the space for generating
the microplasma by a plane perpendicular to the lengthwise
direction of the fine linear portion is ten or more times larger
than a cross-sectional area obtained by cutting a rectangular
parallelepiped that has the opening of the microplasma source and
the fine linear portion of the object as opposite surfaces by a
plane perpendicular to the lengthwise direction of the fine linear
portion.
20. A plasma processing apparatus comprising: a microplasma source
arranged in a vicinity of an object to be processed; a gas supply
unit for supplying plasma generating-use gas to a microplasma
generating-use space of the microplasma source; and a power supply
for supplying electric power to a member located in a vicinity of
the space of the microplasma source, the microplasma generating-use
space of the microplasma source comprising a gas flow passage space
separately from an opening of the microplasma source, the gas flow
passage space communicating with a gas supply inlet to which the
gas is supplied and a gas exhaust outlet which is provided
separately from the opening of the microplasma source opposite to
the object and from which the gas supplied to the gas flow passage
space is exhausted, and the fine linear portion being formed on the
object by generating microplasma in the microplasma generating-use
space of the microplasma source while flowing the gas parallel to
the object along a lengthwise direction of the fine linear portion
to be formed on the object in the vicinity of the opening from the
gas supply inlet toward the gas exhaust outlet in the microplasma
generating-use space of the microplasma source and by making
activated particles discharged from the opening of the microplasma
source communicating with the space act on the object.
21. The plasma processing apparatus as claimed in claim 20, wherein
the member located in the vicinity of the space of the microplasma
source for supplying the electric power is at least one of an
electrode provided on a side opposite from a surface to be
processed of the object, the object, and the microplasma
source.
22. The plasma processing apparatus as claimed in claim 20, wherein
the gas flow passage space communicating with the gas supply inlet
for carrying out the gas supply and the gas exhaust outlet for
carrying out the gas exhaustion is arranged separately from the
microplasma generating-use space located adjacent to the
object.
23. The plasma processing apparatus as claimed in claim 20, wherein
a cross-sectional area obtained by cutting the gas flow passage
space by a plane perpendicular to the lengthwise direction of the
fine linear portion is larger than a cross-sectional area obtained
by cutting a rectangular parallelepiped that has the opening of the
microplasma source and the fine linear portion of the object as
opposite surfaces by a plane perpendicular to the lengthwise
direction of the fine linear portion.
24. The plasma processing apparatus as claimed in claim 20, wherein
a cross-sectional area obtained by cutting the gas flow passage
space by a plane perpendicular to the lengthwise direction of the
fine linear portion is ten or more times larger than a
cross-sectional area obtained by cutting a rectangular
parallelepiped that has the opening of the microplasma source and
the fine linear portion of the object as opposite surfaces by a
plane perpendicular to the lengthwise direction of the fine linear
portion.
25. The plasma processing apparatus as claimed in claim 16, wherein
the gas supply to the space for generating the microplasma by the
gas supply unit is carried out via a through hole provided at a
wall surface that surrounds the space for generating the
microplasma, and the gas exhaustion from the space for generating
the microplasma is carried out via the space for generating the
microplasma in a direction opposite from the opening of the
microplasma source.
26. The plasma processing apparatus as claimed in claim 16, wherein
the opening of the microplasma source has a width of not smaller
than 0.01 mm and not greater than mm.
27. The plasma processing apparatus as claimed in claim 16, wherein
the opening of the microplasma source has a width of not smaller
than 0.01 mm and not greater than 1 mm.
28. The plasma processing apparatus as claimed in claim 16, wherein
a distance between the opening of the microplasma source and the
object is not smaller than 0.01 mm and not greater than 1 mm.
29. The plasma processing apparatus as claimed in claim 16, wherein
a distance between the opening of the microplasma source and the
object is not smaller than 0.01 mm and not greater than 0.5 mm.
30. A plasma processing apparatus comprising: a high-frequency
power supply for applying high-frequency power; a plasma generating
section provided with a first electrode connected to the
high-frequency power supply, a second electrode arranged opposite
from the first electrode, and a discharge space for generating
plasma discharge between the first electrode and the second
electrode; a gas supply unit for supplying gas to the discharge
space; a control unit for executing control so that a pressure of
the discharge space is 100 Pa to 200 kPa and a product PD of the
pressure P of the discharge space and a thickness D of the
discharge space becomes 0.1 to 120 (Pa.multidot.m); and a moving
unit for moving the plasma generating section and the object
relatively to each other.
31. The plasma processing apparatus as claimed in claim 30, wherein
the moving unit is a plasma generating section moving unit for
moving the plasma generating section with respect to the
object.
32. The plasma processing apparatus as claimed in claim 30, wherein
the moving unit is an object moving unit for moving the object with
respect to the plasma generating section.
33. A plasma processing method comprising: supplying gas to a
discharge space formed between both first and second electrodes
arranged oppositely to each other; generating plasma in the
discharge space by executing control so that a pressure of the
discharge space is maintained at 100 Pa to 200 kPa and a product PD
of the pressure P of the discharge space and a thickness D of the
discharge space becomes 0.1 to 120 (Pa.multidot.m) and applying
high-frequency power to the first electrode; and moving the
generated plasma and the object relatively to each other to process
the object by the generated plasma.
34. The plasma processing apparatus as claimed in claim 16, further
comprising: a control unit for executing control so that a pressure
of the space of the microplasma source is 100 Pa to 200 kPa and a
product PD of the pressure P of the space of the microplasma source
and a thickness D of the space of the microplasma source becomes
0.1 to 120 (Pa.multidot.m); and a moving unit for moving the space
of the microplasma source and the object relatively to each
other.
35. The plasma processing method as claimed in claim 16, wherein,
in forming the fine linear portion on the object, plasma is
generated in the space of the microplasma source by executing
control so that a pressure of the space of the microplasma source
is maintained at 100 Pa to 200 kPa and a product PD of the pressure
P of the space of the microplasma source and a thickness D of the
space of the microplasma source becomes 0.1 to 120 (Pa.multidot.m)
and supplying electric power to the member located in the vicinity
of the space of the microplasma source, and the generated plasma
and the object are moved relatively to each other to form the fine
linear portion on the object by the generated plasma.
Description
BACKGROUND OF THE INVENTION
[0001] The present invention relates to a plasma processing method
and apparatus, particularly to a plasma processing method and
apparatus using a microplasma source, and more particularly to a
plasma processing apparatus and method to be applied to the
manufacturing processes of electronic devices such as
semiconductors and MEMS (Micro Electromechanical Systems).
[0002] In general, a resist process is used when an object to be
processed represented by a substrate on the surface of which a thin
film is formed is subjected to a patterning process. FIG. 23 shows
one example thereof. Referring to FIGS. 23A through 23D, first of
all, a photoresist 27 is coated on the surface of an object 26 to
be processed (see FIG. 23A). Next, if the photoresist 27 is exposed
to light by means of an exposure apparatus and thereafter
developed, then either of the exposed portion or the non-exposed
portion of the photoresist 27 is removed, allowing the photoresist
27 to be patterned into the desired shape (see FIG. 23B).
Subsequently, if the object 26 is placed in a vacuum vessel and
plasma is generated inside the vacuum vessel to subject the object
26 to an etching process with the resist 27 used as a mask, then
the surface of the object 26 is patterned into the desired shape
(see FIG. 23C). Finally, by removing the resist 27 with oxygen
plasma, an organic solvent, or the like, the processing is
completed (see FIG. 23D).
[0003] The above-mentioned resist process, which has been
appropriate for accurately forming a fine pattern, has therefore
come to play an important role in manufacturing electronic devices
such as semiconductors. However, there is a defect that the process
is complicated.
[0004] Accordingly, there is currently being examined a new
processing method that uses no resist process. As one example
thereof, FIGS. 24-25 show perspective views of a processing
apparatus provided with a microplasma source employed in a prior
art example. FIG. 25 shows a sectional view cut in the plane A of
FIG. 24. Referring to FIGS. 24 and 25, a space 73 (dot-hatching
portion of FIG. 25, hereinafter referred to as a plasma space 73)
for generating microplasma is formed between two ceramic plates 71
and 72. Side portions of the ceramic plates 71 and 72 are bonded to
ceramic bars 74, 75, and 76. Gas is supplied from a gas supply unit
77 to the plasma space 73 via a pipe 78 and the ceramic bar 76. A
through hole that serves as a gas supply inlet is provided at the
ceramic bar 76 and joined to the pipe 78. By arranging an opening
80 of the microplasma source in the vicinity of a substrate 81 that
serves as an object to be processed, supplying high-frequency power
of 13.56 MHz from a high-frequency power supply 82 to a
high-frequency electrode 83 while supplying gas to the plasma space
73 and grounding a grounding electrode 84, plasma is generated in
the plasma space 73 to make activated particles emitted from the
opening 80 of the microplasma source act on the substrate 81,
allowing a fine linear portion 85 to be processed on the surface of
the substrate 81. It is to be noted that the high-frequency
electrode 83 and the grounding electrode 84 are parallel plate
electrodes provided with interposition of the plasma space 73. The
width B of the opening 80 of the microplasma source is 1 mm, and
the distance C between the opening 80 of the microplasma source and
the substrate 81 is 0.1 mm.
[0005] For example, on the condition that He is supplied by 2000
sccm and CF.sub.4 is supplied by 4 sccm as gas and high-frequency
power of 30 W is supplied, a molybdenum thin film formed on the
substrate 81 can be subjected to an etching process.
[0006] However, in the processing described in connection with the
prior art example, the active species dissociated by the plasma
effuse along the surface of the substrate 81 as indicated by arrows
in FIG. 25, and this has therefore led to an issue that the
processing has been disadvantageously effected beyond the desired
fine linear portion. FIG. 26 shows the obtained etching profile. In
this case, on the assumption that the depth of the portion most
deeply etched was D and the width of the portion shallower by
D.times.0.8 than the bottom of the pattern was a processing width
E, then E was 3.1 mm. Since the width B of the opening 10 of the
microplasma source was 1 mm, then the processing width E
disadvantageously became three or more times the width.
[0007] The present invention is accomplished in view of the
aforementioned conventional issues and has the object of providing
a plasma processing method and apparatus for accurately forming the
desired fine linear portion by plasma processing.
SUMMARY OF THE INVENTION
[0008] In order to achieve the aforementioned object, the present
invention is constructed as follows.
[0009] According to the first aspect of the present invention,
there is provided a plasma processing method for forming a fine
linear portion on an object to be processed by generating
microplasma in a space of a microplasma source arranged in a
vicinity of the object to be processed while supplying gas to the
space of the microplasma source and supplying electric power to a
member located in the vicinity of the space of the microplasma and
by making activated particles discharged from an opening of the
microplasma source connected to the space act on the object to be
processed, the method comprising:
[0010] forming the fine linear portion on the object to be
processed while flowing the gas to a neighborhood of the opening,
parallel to the object to be processed, along a lengthwise
direction of the fine linear portion.
[0011] According to the second aspect of the present invention,
there is provided the plasma processing method of the first aspect,
wherein the member located in the vicinity of the space of the
microplasma source for supplying electric power is at least one of
an electrode provided on a side opposite from a surface to be
processed of the object to be processed, the object to be
processed, and the microplasma source.
[0012] According to the third aspect of the present invention,
there is provided the plasma processing method of the first or
second aspect, wherein the space of the microplasma source has a
gas supply inlet to which the gas is supplied and a gas exhaust
outlet which is provided separately from the opening of the
microplasma source and from which the gas supplied to the space is
exhausted.
[0013] According to the fourth aspect of the present invention,
there is provided the plasma processing method of any one of the
first through third aspects, wherein the fine linear portion is
formed on the object to be processed while flowing the gas to the
neighborhood of the opening parallel to the object to be processed
along the lengthwise direction of the fine linear portion in a
state in which a cross-sectional area obtained by cutting the space
for generating the microplasma by a plane perpendicular to the
lengthwise direction of the fine linear portion is larger than a
cross-sectional area obtained by cutting a rectangular
parallelepiped that has the opening of the microplasma source and
the fine linear portion of the object to be processed as opposite
surfaces by a plane perpendicular to the lengthwise direction of
the fine linear portion.
[0014] Furthermore, according to the fifth aspect of the present
invention, there is provided the plasma processing method of any
one of the first through third aspects, wherein the fine linear
portion is formed on the object to be processed while flowing the
gas to the neighborhood of the opening parallel to the object to be
processed along the lengthwise direction of the fine linear portion
in a state in which a cross-sectional area obtained by cutting the
space for generating the microplasma by a plane perpendicular to
the lengthwise direction of the fine linear portion is ten or more
times larger than a cross-sectional area obtained by cutting a
rectangular parallelepiped that has the opening of the microplasma
source and the fine linear portion of the object to be processed as
opposite surfaces by a plane perpendicular to the lengthwise
direction of the fine linear portion.
[0015] According to the sixth aspect of the present invention,
there is provided the plasma processing method of any one of the
third through fifth aspects, wherein the fine linear portion is
formed on the object to be processed while the gas supplied from
the gas supply inlet is exhausted by 70% or more in terms of a
supply flow rate from the gas exhaust outlet.
[0016] According to the seventh aspect of the present invention,
there is provided the plasma processing method of any one of the
first through sixth aspects, wherein the fine linear portion is
formed on the object to be processed while flowing the gas through
a gas flow passage provided parallel to the object to be processed
along the lengthwise direction of the fine linear portion and
discharging the activated particles from the opening narrower than
the gas flow passage.
[0017] According to the eighth aspect of the present invention,
there is provided the plasma processing method of the seventh
aspect, wherein the fine linear portion is formed on the object to
be processed while flowing the gas through a gas flow passage
provided parallel to the object to be processed along the
lengthwise direction of the fine linear portion and carrying out
gas supply to the gas flow passage and gas exhaustion from the gas
flow passage in a space separated from a space brought in contact
with the object to be processed.
[0018] According to the ninth aspect of the present invention,
there is provided the plasma processing method of any one of the
seventh through eighth aspects, wherein the fine linear portion is
formed on the object to be processed while flowing the gas to the
neighborhood of the opening parallel to the object to be processed
along the lengthwise direction of the fine linear portion in a
space where a cross-sectional area obtained by cutting the gas flow
passage by a plane perpendicular to the lengthwise direction of the
fine linear portion is larger than a cross-sectional area obtained
by cutting a rectangular parallelepiped that has the opening of the
microplasma source and the fine linear portion of the object to be
processed as opposite surfaces by a plane perpendicular to the
lengthwise direction of the fine linear portion.
[0019] Furthermore, according to the tenth aspect of the present
invention, there is provided the plasma processing method of any
one of the seventh through eighth aspects, wherein the fine linear
portion is formed on the object to be processed while flowing the
gas to the neighborhood of the opening parallel to the object to be
processed along the lengthwise direction of the fine linear portion
in a space where a cross-sectional area obtained by cutting the gas
flow passage by a plane perpendicular to the lengthwise direction
of the fine linear portion is ten or more times larger than a
cross-sectional area obtained by cutting a rectangular
parallelepiped that has the opening of the microplasma source and
the fine linear portion of the object to be processed as opposite
surfaces by a plane perpendicular to the lengthwise direction of
the fine linear portion.
[0020] According to the eleventh aspect of the present invention,
there is provided a plasma processing method for forming a fine
linear portion on an object to be processed by generating
microplasma in a space of a microplasma source arranged in a
vicinity of the object to be processed while supplying gas to the
microplasma source and supplying electric power to at least one of
an electrode provided on a side opposite from a surface to be
processed of the object to be processed, the object to be
processed, and the microplasma source and by making activated
particles discharged from an opening of the microplasma source
connected to the space act on the object to be processed, the
method comprising:
[0021] forming the fine linear portion on the object to be
processed while flowing the gas to a neighborhood of the opening
parallel to the object to be processed along a lengthwise direction
of the fine linear portion by carrying out gas supply to the space
for generating the microplasma via a through hole provided at a
wall surface that surrounds the space for generating the
microplasma and carrying out gas exhaustion from the space for
generating the microplasma via the space for generating the
microplasma toward a side opposite from a side on which the fine
linear portion of the object to be processed is disposed.
[0022] Preferably, the above-mentioned plasma processing methods
are effective particularly when the processing is the processing of
etching the fine linear portion of the object to be processed.
[0023] Preferably, in the plasma processing methods, it is
acceptable to supply high-frequency power across parallel plate
electrodes provided so as to place the space for generating the
microplasma between them or supply pulse power across the parallel
plate electrodes provided so as to place the space for generating
microplasma between them.
[0024] Otherwise, it is acceptable to supply high-frequency power
across an electrode located opposite from the object to be
processed via the space for generating the microplasma and an
electrode provided on the side opposite from the object to be
processed or the surface to be processed of the object to be
processed or to supply pulse power between the electrode located
opposite from the object to be processed via the space for
generating the microplasma and the electrode provided on the side
opposite from the object to be processed or the surface to be
processed of the object to be processed.
[0025] According to the twelfth aspect of the present invention,
the opening of the microplasma source preferably has a width of not
smaller than 0.01 mm and not greater than 5 mm.
[0026] Furthermore, according to the thirteenth aspect of the
present invention, the opening of the microplasma source more
preferably has a width of not smaller than 0.01 mm and not greater
than 1 mm.
[0027] Moreover, according to the fourteenth aspect of the present
invention, a distance between the opening of the microplasma source
and the object to be processed preferably is not smaller than 0.01
mm and not greater than 1 mm.
[0028] Furthermore, according to the fifteenth aspect of the
present invention, the distance between the opening of the
microplasma source and the object to be processed more preferably
is not smaller than 0.01 mm and not greater than 0.5 mm.
[0029] Furthermore, according to the above-mentioned plasma
processing methods, it is preferable to carry out gas supply
through a gas flow passage provided inside the parallel plate
electrodes.
[0030] According to the sixteenth aspect of the present invention,
there is provided a plasma processing apparatus comprising:
[0031] a microplasma source arranged in a vicinity of an object to
be processed;
[0032] a gas supply unit for supplying plasma generating-use gas to
a space of the microplasma source; and
[0033] a power supply for supplying electric power to a member
located in a vicinity of the space of the microplasma source,
[0034] the space of the microplasma source communicating with a gas
supply inlet to which the gas is supplied and a gas exhaust outlet
which is provided separately from an opening of the microplasma
source opposite to the object to be processed and from which the
gas supplied to the space is exhausted, and
[0035] the fine linear portion being formed on the object to be
processed by generating microplasma in the space of the microplasma
source while flowing the gas parallel to the object to be
processed, along a lengthwise direction of the fine linear portion
to be formed on the object to be processed, in the vicinity of the
opening, from the gas supply inlet toward the gas exhaust outlet in
the space of the microplasma source and by making activated
particles discharged from the opening of the microplasma source
communicating with the space act on the object to be processed.
[0036] According to the seventeenth aspect of the present
invention, there is provided the plasma processing method of the
sixteenth aspect, wherein the member located in the vicinity of the
space of the microplasma source for supplying the electric power is
at least one of an electrode provided on a side opposite from a
surface to be processed of the object to be processed, the object
to be processed, and the microplasma source.
[0037] According to the eighteenth aspect of the present invention,
there is provided the plasma processing apparatus of the sixteenth
or seventeenth aspect, wherein a cross-sectional area obtained by
cutting the space for generating the microplasma by a plane
perpendicular to the lengthwise direction of the fine linear
portion is larger than a cross-sectional area obtained by cutting a
rectangular parallelepiped that has the opening of the microplasma
source and the fine linear portion of the object to be processed as
opposite surfaces by a plane perpendicular to the lengthwise
direction of the fine linear portion.
[0038] Furthermore, according to the nineteenth aspect of the
present invention, there is provided a plasma processing apparatus
of the sixteenth or seventeenth aspect, wherein a cross-sectional
area obtained by cutting the space for generating the microplasma
by a plane perpendicular to the lengthwise direction of the fine
linear portion is ten or more times larger than a cross-sectional
area obtained by cutting a rectangular parallelepiped that has the
opening of the microplasma source and the fine linear portion of
the object to be processed as opposite surfaces by a plane
perpendicular to the lengthwise direction of the fine linear
portion.
[0039] According to the twentieth aspect of the present invention,
there is provided a plasma processing apparatus comprising:
[0040] a microplasma source arranged in a vicinity of an object to
be processed;
[0041] a gas supply unit for supplying plasma generating-use gas to
a microplasma generating-use space of the microplasma source;
and
[0042] a power supply for supplying electric power to a member
located in a vicinity of the space of the microplasma source,
[0043] the microplasma generating-use space of the microplasma
source comprising a gas flow passage space separately from an
opening of the microplasma source, the gas flow passage space
communicating with a gas supply inlet to which the gas is supplied
and a gas exhaust outlet which is provided separately from the
opening of the microplasma source opposite to the object to be
processed and from which the gas supplied to the gas flow passage
space is exhausted, and
[0044] the fine linear portion being formed on the object to be
processed by generating microplasma in the microplasma
generating-use space of the microplasma source while flowing the
gas parallel to the object to be processed, along a lengthwise
direction of the fine linear portion to be formed on the object to
be processed, in the vicinity of the opening, from the gas supply
inlet toward the gas exhaust outlet in the gas flow passage space
of the microplasma source and by making activated particles
discharged from the opening of the microplasma source communicating
with the space act on the object to be processed.
[0045] According to the twenty-first aspect of the present
invention, there is provided the plasma processing apparatus of the
twentieth aspect, wherein the member located in the vicinity of the
space of the microplasma source for supplying the electric power is
at least one of an electrode provided on a side opposite from a
surface to be processed of the object to be processed, the object
to be processed, and the microplasma source.
[0046] According to the twenty-second aspect of the present
invention, there is provided the plasma processing apparatus of the
twentieth or twenty-first aspect, wherein the gas flow passage
space communicating with the gas supply inlet for carrying out the
gas supply and the gas exhaust outlet for carrying out the gas
exhaustion is arranged separately from the microplasma
generating-use space located adjacent to the object to be
processed.
[0047] According to the twenty-third aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the twentieth through twenty-second aspects, wherein a
cross-sectional area obtained by cutting the gas flow passage space
by a plane perpendicular to the lengthwise direction of the fine
linear portion is larger than a cross-sectional area obtained by
cutting a rectangular parallelepiped that has the opening of the
microplasma source and the fine linear portion of the object to be
processed as opposite surfaces by a plane perpendicular to the
lengthwise direction of the fine linear portion.
[0048] According to the twenty-fourth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the twentieth through twenty-second aspects, wherein a
cross-sectional area obtained by cutting the gas flow passage space
by a plane perpendicular to the lengthwise direction of the fine
linear portion is ten or more times larger than a cross-sectional
area obtained by cutting a rectangular parallelepiped that has the
opening of the microplasma source and the fine linear portion of
the object to be processed as opposite surfaces by a plane
perpendicular to the lengthwise direction of the fine linear
portion.
[0049] According to the twenty-fifth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-fourth aspects, wherein the gas
supply to the space for generating the microplasma by the gas
supply unit is carried out via a through hole provided at a wall
surface that surrounds the space for generating the microplasma,
and the gas exhaustion from the space for generating the
microplasma is carried out via the space for generating the
microplasma in a direction opposite from the opening of the
microplasma source.
[0050] The above-mentioned plasma processing apparatuses are
particularly preferable when the processing is the processing of
etching the fine linear portion of the object to be processed.
[0051] In the above-mentioned plasma processing apparatuses, it is
acceptable to supply high-frequency power across the parallel plate
electrodes provided so as to place the space for generating the
microplasma between them or supply pulse power across the parallel
plate electrodes provided so as to place the space for generating
microplasma between them.
[0052] Otherwise, it is acceptable to supply high-frequency power
across an electrode located opposite from the object to be
processed via a space for generating the microplasma and an
electrode provided on the side opposite from the object to be
processed or the surface to be processed of the object to be
processed or to supply pulse power between the electrode located
opposite from the object to be processed via the space for
generating the microplasma and the electrode provided on the side
opposite from the object to be processed or the surface to be
processed of the object to be processed.
[0053] According to the twenty-sixth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-fifth aspects, wherein the
opening of the microplasma source has a width of not smaller than
0.01 mm and not greater than 5 mm.
[0054] According to the twenty-seventh aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-fifth aspects, wherein the
opening of the microplasma source has a width of not smaller than
0.01 mm and not greater than 1 mm.
[0055] According to the twenty-eighth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-seventh aspects, wherein the
distance between the opening of the microplasma source and the
object to be processed is not smaller than 0.01 mm and not greater
than 1 mm.
[0056] According to the twenty-ninth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-seventh aspects, wherein the
distance between the opening of the microplasma source and the
object to be processed is not smaller than 0.01 mm and not greater
than 0.5 mm.
[0057] According to the thirtieth aspect of the present invention,
there is provided a plasma processing apparatus comprising:
[0058] a high-frequency power supply for applying high-frequency
power;
[0059] a plasma generating section provided with a first electrode
connected to the high-frequency power supply, a second electrode
arranged opposite from the first electrode and a discharge space
for generating plasma discharge between the first electrode and the
second electrode;
[0060] a gas supply unit for supplying gas to the discharge
space;
[0061] a control unit for executing control so that a pressure of
the discharge space is 100 Pa to 200 kPa and a product PD of the
pressure P of the discharge space and a thickness D of the
discharge space becomes 0.1 to 120 (Pa.multidot.m); and
[0062] a moving unit for moving the plasma generating section and
the object to be processed relatively to each other.
[0063] According to the thirty-first aspect of the present
invention, there is provided the plasma processing apparatus of the
thirtieth aspect, wherein the moving unit is a plasma generating
section moving unit for moving the plasma generating section with
respect to the object to be processed.
[0064] According to the thirty-second aspect of the present
invention, there is provided the plasma processing apparatus of the
thirtieth aspect, wherein the moving unit is an object moving unit
for moving the object to be processed with respect to the plasma
generating section.
[0065] According to the thirty-third aspect of the present
invention, there is provided a plasma processing method
comprising:
[0066] supplying gas to a discharge space formed between both first
and second electrodes arranged oppositely to each other;
[0067] generating plasma in the discharge space by executing
control so that a pressure of the discharge space is maintained at
100 Pa to 200 kPa and a product PD of the pressure P of the
discharge space and a thickness D of the discharge space becomes
0.1 to 120 (Pa.multidot.m) and applying high-frequency power to the
first electrode; and
[0068] moving the generated plasma and the object to be processed
relatively to each other to process the object to be processed by
the generated plasma.
[0069] According to the thirty-fourth aspect of the present
invention, there is provided the plasma processing apparatus of any
one of the sixteenth through twenty-ninth aspects, further
comprising:
[0070] a control unit for executing control so that a pressure of
the space of the microplasma source is 100 Pa to 200 kPa and a
product PD of the pressure P of the space of the microplasma source
and a thickness D of the space of the microplasma source becomes
0.1 to 120 (Pa.multidot.m); and
[0071] a moving unit for moving the space of the microplasma source
and the object to be processed relatively to each other.
[0072] According to the thirty-fifth aspect of the present
invention, there is provided the plasma processing method of any
one of the first through fifteenth aspects, wherein,
[0073] in forming the fine linear portion on the object, plasma is
generated in the space of the microplasma source by executing
control so that a pressure of the space of the microplasma source
is maintained at 100 Pa to 200 kPa and a product PD of the pressure
P of the space of the microplasma source and a thickness D of the
space of the microplasma source becomes 0.1 to 120 (Pa.multidot.m)
and supplying electric power to the member located in the vicinity
of the space of the microplasma source, and
[0074] the generated plasma and the object to be processed are
moved relatively to each other to form the fine linear portion on
the object to be processed by the generated plasma.
BRIEF DESCRIPTION OF THE DRAWINGS
[0075] These and other aspects and features of the present
invention will become clear from the following description taken in
conjunction with the preferred embodiments thereof with reference
to the accompanying drawings, in which:
[0076] FIG. 1 is a perspective view showing the construction of a
plasma processing apparatus employed in a first embodiment of the
present invention;
[0077] FIG. 2 is a sectional view showing the construction of the
plasma processing apparatus employed in the first embodiment of the
present invention;
[0078] FIG. 3 is a graph showing an etching profile in the first
embodiment of the present invention;
[0079] FIG. 4 is a sectional view showing the construction of the
plasma processing apparatus employed in the first embodiment of the
present invention;
[0080] FIG. 5 is a perspective view showing the construction of a
plasma processing apparatus employed in a second embodiment of the
present invention;
[0081] FIG. 6 is a sectional view showing the construction of the
plasma processing apparatus employed in the second embodiment of
the present invention;
[0082] FIG. 7 is a graph showing an etching profile in the second
embodiment of the present invention;
[0083] FIG. 8 is a sectional view showing the construction of the
plasma processing apparatus employed in the second embodiment of
the present invention;
[0084] FIG. 9 is a perspective view showing the construction of a
plasma processing apparatus employed in a third embodiment of the
present invention;
[0085] FIG. 10 is a sectional view showing the construction of the
plasma processing apparatus employed in the third embodiment of the
present invention;
[0086] FIG. 11A and FIG. 11B are sectional views showing the
construction of the plasma processing apparatus employed in the
third embodiment of the present invention and the construction of a
plasma processing apparatus employed in its modification example,
respectively;
[0087] FIG. 12 is a graph showing an etching profile in the third
embodiment of the present invention;
[0088] FIG. 13 is a sectional view showing the construction of the
plasma processing apparatus employed in the third embodiment of the
present invention;
[0089] FIG. 14 is a perspective view showing the construction of a
plasma processing apparatus employed in a fourth embodiment of the
present invention;
[0090] FIG. 15 is a sectional view showing the construction of the
plasma processing apparatus employed in the fourth embodiment of
the present invention;
[0091] FIG. 16 is a sectional view showing the construction of the
plasma processing apparatus employed in the fourth embodiment of
the present invention;
[0092] FIG. 17 is a graph showing an etching profile in the fourth
embodiment of the present invention;
[0093] FIG. 18 is a perspective view showing the construction of a
plasma processing apparatus employed in a fifth embodiment of the
present invention;
[0094] FIG. 19 is a sectional view showing the construction of the
plasma processing apparatus employed in the fifth embodiment of the
present invention;
[0095] FIG. 20 is a perspective view showing the construction of a
plasma processing apparatus employed in a sixth embodiment of the
present invention;
[0096] FIG. 21 is a sectional view showing the construction of the
plasma processing apparatus employed in the sixth embodiment of the
present invention;
[0097] FIG. 22 is a perspective view showing the construction of a
plasma processing apparatus employed in a seventh embodiment of the
present invention;
[0098] FIGS. 23A, 23B, 23C, and 23D are views showing patterning
processes used in a prior art example;
[0099] FIG. 24 is a perspective view showing the construction of a
plasma processing apparatus employed in a prior art example;
[0100] FIG. 25 is a sectional view showing the construction of the
plasma processing apparatus employed in the prior art example;
[0101] FIG. 26 is a graph showing an etching profile in the prior
art example;
[0102] FIG. 27 is a schematic constituent view of a plasma
processing apparatus of an eighth embodiment of the present
invention;
[0103] FIG. 28 is a schematic constituent view of a movement means
in the eighth embodiment;
[0104] FIGS. 29A, 29B, 29C, and 29D are explanatory views of
processing steps in the eighth embodiment;
[0105] FIG. 30 is a schematic constituent view of a plasma
processing apparatus of a ninth embodiment of the present
invention;
[0106] FIG. 31 is a schematic constituent view of a plasma
processing apparatus of a tenth embodiment of the present
invention;
[0107] FIG. 32 is a perspective view showing the construction of a
plasma processing apparatus of a first prior art example;
[0108] FIG. 33 is a sectional view showing the construction of a
plasma processing apparatus of a second prior art example;
[0109] FIG. 34 is a partially see-through schematic constituent
view of a plasma processing apparatus of an eleventh embodiment of
the present invention; and
[0110] FIG. 35 is a schematic constituent view of a plasma
processing apparatus of a twelfth embodiment of the present
invention.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0111] Before the description of the present invention proceeds, it
is to be noted that like parts are designated by like reference
numerals throughout the accompanying drawings.
[0112] Embodiments of the present invention will be described in
detail below with reference to the drawings.
[0113] A first embodiment of the present invention will be
described below with reference to FIGS. 1 through 4.
[0114] FIG. 1 shows a perspective view of a plasma processing
apparatus provided with a microplasma source employed in the first
embodiment of the present invention. FIG. 2 shows a sectional view
cut in the plane A of FIG. 1. Referring to FIGS. 1 and 2, a
microplasma generating-use space 3 (dot-hatching portion in FIG. 2,
hereinafter referred to as a plasma space 3) of a roughly
rectangular parallelepiped configuration for generating microplasma
is formed as a microplasma source between two ceramic dielectric
plates (ceramic plates as one example) 1 and 2. Three side portions
of the ceramic dielectric plates 1 and 2 are bonded to ceramic
bar-shaped dielectric members (ceramic bars as one example) 4, 5
and 6, and a substrate 11, which serves as one example of the
object to be processed, is oppositely disposed with interposition
of a minute gap on the remaining one side portion, constituting a
microplasma source. Gas is supplied from a gas supply unit 7 to the
plasma space 3 via a pipe 8 and a gas-introducing section 9 (one
example of the gas supply inlet) The gas-introducing section 9 is
made of ceramic, provided with through holes that serve as gas
supply inlets and joined to the pipe 8. On the other hand, a gas
exhaust outlet 90 is formed at a side portion, which is located
between the ceramic dielectric plates 1 and 2 and opposite from the
gas-introducing section 9 that functions as one example of the gas
supply inlet, without contact with the ceramic bar-shaped
dielectric member 4. By arranging an elongate rectangular opening
10 of the microplasma source in the vicinity of the substrate 11
that serves as the object to be processed, supplying the gas into
the plasma space 3 from the gas-introducing section 9 and
exhausting the gas inside the plasma space 3 from the gas exhaust
outlet 90, the gas flowed along the lengthwise direction of the
opening 10 parallel to the substrate 11 in the vicinity of the
opening 10. By supplying high-frequency power of 13.56 MHz from a
high-frequency power supply 12 to a high-frequency electrode 13
that serves as one example of the member located in the vicinity of
the space 3 of the microplasma source and grounding a grounding
electrode 14, plasma is generated in the plasma space 3, and the
activated particles discharged from the opening 10 of the
microplasma source act on the substrate 11, allowing a fine linear
portion 15 to be formed on the surface of the substrate 11. It is
to be noted that the high-frequency electrode 13 and the grounding
electrode 14 are parallel plate electrodes provided so as to place
the plasma space 3 between them. Moreover, as one example, the
width B of the opening 10 of the microplasma source is 1 mm, and
the distance C between the opening 10 of the microplasma source and
the substrate 11 is 0.1 mm.
[0115] A plasma processing control unit 441 is connected to a
high-frequency power supply 12, a gas supply unit 7, and a memory
442, which stores various sorts of plasma processing information
for the substrate 11, and executes application control of
high-frequency power from the high-frequency power supply 12 to the
electrode 13 and gas supply control with the gas supply unit 7 on
the basis of the various sorts of plasma processing information
stored in the memory 442. By this operation, appropriate plasma
processing can be automatically carried out.
[0116] The microplasma source, which is operable at several pascals
to several times the atmospheric pressure, typically operates
within a range of a pressure of 10000 Pa to about triple the
atmospheric pressure. In particular, the operation at or around the
atmospheric pressure, which requires neither strict sealing
structure nor special exhaust unit and appropriately restrains the
diffusion of the plasma and the activated particles, is especially
preferable.
[0117] As one concrete example, a molybdenum thin film, which
served as one example of the fine linear portion 15 formed on the
substrate 11 on the condition that He was supplied by 2000 sccm and
CF.sub.4 was supplied by 4 sccm, as a gas, and high-frequency power
of 30 W was supplied, was subjected to an etching process.
Consequently, an etching profile as shown in FIG. 3 was obtained.
In this case, on the assumption that the depth of the portion most
deeply etched was D and the width of the portion shallower by
D.times.0.8 than the bottom of the pattern was a processing width
E, then E was 1.1 mm. Since the width B of the opening 10 of the
microplasma source was 1 mm, the processing width E was only 10%
larger than this, and the formation accuracy was remarkably
improved in comparison with the prior art example.
[0118] The reason why the formation accuracy is improved as
described above is presumably because the gas flows from the
gas-introducing section 9 toward the gas exhaust outlet 90 parallel
to the substrate 11 along the lengthwise direction of the fine
linear portion 15 and in the vicinity of the opening 10, making it
difficult for the activated particles generated by the plasma to
come in contact with the substrate surface portion located outside
the fine linear portion 15.
[0119] In the first embodiment of the present invention, as shown
in FIG. 4 as one example, a cross-sectional area 16 (dot-hatching
portion in FIG. 4) of a cross section obtained by cutting the
plasma space 3 by a plane perpendicular to the lengthwise direction
of the fine linear portion 15 is twenty times as large as a
cross-sectional area 17 (rectangular gray portion in FIG. 4) of a
cross section obtained by cutting a rectangular parallelepiped,
which has the opening 10 of the microplasma source and the fine
linear portion 15 of the object as opposite surfaces, by a plane
perpendicular to the lengthwise direction of the fine linear
portion 15. In order to improve the formation accuracy, the
cross-sectional area of the cross section obtained by cutting the
plasma space by the plane perpendicular to the lengthwise direction
of the fine linear portion is required to be larger than the
cross-sectional area of the cross section obtained by cutting the
rectangular parallelepiped, which has the opening of the
microplasma source and the fine linear portion of the object as
opposite surfaces, by the plane perpendicular to the lengthwise
direction of the fine linear portion. However, in order to obtain
higher formation accuracy, this ratio preferably is roughly ten or
more times greater. If this ratio is smaller than 10 times, then
the activated particles generated by plasma are discharged
outwardly of the fine linear portion of the surface of the
substrate, and the formation accuracy is degraded.
[0120] According to the plasma processing method of the first
embodiment of the present invention, microplasma is generated
inside the space 3 of the microplasma source by supplying electric
power to the microplasma source that serves as one example of the
member located in the vicinity of the space 3 of the microplasma
source while supplying the gas into the space of the microplasma
source arranged in the vicinity of the substrate 11, and the
activated particles discharged from the opening 10 of the
microplasma source joined to the space 3 are made to act on the
substrate 11 to form the fine linear portion 15 on the surface of
the substrate 11. Therefore, the fine linear portion can be formed
on the object while flowing the gas parallel to the substrate 11
along the lengthwise direction of the fine linear portion 15 and in
the vicinity of the opening 10, and the desired fine linear portion
15 can be accurately processed by plasma.
[0121] Furthermore, according to the plasma processing apparatus of
the first embodiment of the present invention, there are provided
the microplasma source arranged in the vicinity of the substrate
11, the gas supply unit 7 for supplying the plasma generating-use
gas to the space 3 of the microplasma source, and the power supply
12 for supplying power to the member located in the vicinity of the
space 3 of the microplasma source, e.g., the microplasma source.
The space 3 of the microplasma source communicates with the gas
supply inlet 9 to which the gas is supplied and the gas exhaust
outlet 90, which is provided separately from the opening 10 of the
microplasma source opposite to the substrate 11 and from which the
gas supplied into the space 3 is exhausted. The microplasma is
generated inside the space 3 of the microplasma source while
flowing the gas parallel to the substrate 11 along the lengthwise
direction of the fine linear portion 15 to be formed on the
substrate 11 and in the vicinity of the opening 10 from the gas
supply inlet 9 toward the gas exhaust outlet 90 in the space 3 of
the microplasma source to make the activated particles discharged
from the opening 10 of the microplasma source act on the substrate
11, thereby forming the fine linear portion 15 on the substrate 11.
Therefore, the structure of flowing the gas parallel to the
substrate 11 along the lengthwise direction of the fine linear
portion 15 and in the vicinity of the opening 10 can be formed, and
the desired fine linear portion 15 can be accurately processed by
plasma.
[0122] A second embodiment of the present invention will be
described next with reference to FIGS. 5 through 8.
[0123] FIG. 5 shows a perspective view of a plasma processing
apparatus provided with a microplasma source employed in the second
embodiment of the present invention. FIG. 6 shows a sectional view
cut in the plane A of FIG. 5. Referring to FIGS. 5 and 6, a
microplasma generating-use space 3 (dot-hatching portion in FIG. 6,
hereinafter referred to as a plasma space 3) of a roughly
rectangular parallelepiped shape for generating microplasma is
formed between two ceramic dielectric plates 1 and 2. Three side
portions of the ceramic dielectric plates 1 and 2 are bonded to
ceramic bar-shaped dielectric members 4, 5, and 6, and a substrate
11, which serves as one example of the object to be processed
(object), is oppositely disposed with interposition of a minute gap
on the remaining one side portion. Gas is supplied from a gas
supply unit 7 to a gas flow passage 18 constructed of a gas flow
passage space provided parallel to the substrate 11 along the
lengthwise direction of a fine linear portion 15 via a pipe 8 and a
gas-introducing section 9 (one example of the gas supply inlet).
The gas flow passage 18 is continuous to the plasma space 3 and is
formed so that its spatial dimension in the direction of thickness
of the ceramic dielectric plates 1 and 2 becomes larger than that
of the plasma space 3 due to recess portions 1a and 2a similarly
formed on the opposed surfaces of the ceramic dielectric plates 1
and 2 on the ceramic bar-shaped dielectric member 6 side. This is
the point greatly different from the plasma processing apparatus of
the first embodiment. The gas-introducing section 9 is made of
ceramic, provided with a through hole that serves as a gas supply
inlet and joined to the pipe 8. On the other hand, a gas exhaust
outlet 90 is formed at a side portion, which is located between the
ceramic dielectric plates 1 and 2 and opposite from the
gas-introducing section 9 without contact with the ceramic
bar-shaped dielectric member 4. By arranging an elongate
rectangular opening 10 of the microplasma source in the vicinity of
the substrate 11 that serves as the object, supplying the gas into
the plasma space 3, and exhausting the gas inside the plasma space
3 from the gas exhaust outlet 90, the gas is flowed along the
lengthwise direction of the opening 10 parallel to the substrate 11
and in the vicinity of the opening 10. By supplying high-frequency
power of 13.56 MHz from a high-frequency power supply 12 to a
high-frequency electrode 13 and grounding a grounding electrode 14,
plasma is generated in the plasma space 3, and the activated
particles discharged from the opening 10 of the microplasma source
act on the substrate 11, allowing a fine linear portion 15 to be
formed on the surface of the substrate 11. It is to be noted that
the high-frequency electrode 13 and the grounding electrode 14 are
parallel plate electrodes provided so as to place the plasma space
3 between them. Moreover, as one example, the width B of the
opening 10 of the microplasma source is 1 mm, and the distance C
between the opening 10 of the microplasma source and the substrate
11 is 0.1 mm.
[0124] The microplasma source, which is operable at several pascals
to several times the atmospheric pressure, typically operates
within a range of a pressure of 10000 Pa to about triple the
atmospheric pressure. In particular, the operation at or around the
atmospheric pressure, which requires neither strict sealing
structure nor special exhaust unit and appropriately restrains the
diffusion of the plasma and the activated particles, is especially
preferable.
[0125] According to one concrete example, a molybdenum thin film,
which served as one example of the fine linear portion 15 formed on
the substrate 11 on the condition that He was supplied by 2000 sccm
and CF.sub.4 was supplied by 4 sccm, as a gas, and a high-frequency
power of 30 W was supplied, was subjected to an etching process.
Consequently, an etching profile as shown in FIG. 7 was obtained.
In this case, on the assumption that the depth of the portion most
deeply etched was D and the width of the portion shallower by
D.times.0.8 than the bottom of the pattern was a processing width
E, then E was 0.91 mm. Since the width B of the opening 10 of the
microplasma source was 1 mm, the processing width E was smaller
than this, and the formation accuracy was remarkably improved in
comparison with the prior art example.
[0126] The reason why the formation accuracy is improved as
described above is presumably because the gas flows through the gas
flow passage 18 provided from the gas-introducing section 9 toward
the gas exhaust outlet 90 parallel to the substrate 11 along the
lengthwise direction of the fine linear portion 15 and the
activated particles are discharged from the opening 10 narrower
than the gas flow passage 18, making it difficult for the activated
particles generated by the plasma to come in contact with the
substrate surface portion located outside the fine linear portion
15.
[0127] In the second embodiment of the present invention, shown as
one example in FIG. 8, a cross-sectional area 19 (dot-hatching
portion in FIG. 8) of a cross section obtained by cutting the gas
flow passage 18 by a plane perpendicular to the lengthwise
direction of the fine linear portion 15 is twenty-four times as
large as a cross-sectional area 17 (rectangular gray portion in
FIG. 8) of a cross section obtained by cutting a rectangular
parallelepiped, which has the opening 10 of the microplasma source
and the fine linear portion 15 of the object as opposite surfaces,
by a plane perpendicular to the lengthwise direction of the fine
linear portion 15. In order to improve the formation accuracy, the
cross-sectional area of the cross section obtained by cutting the
gas flow passage by the plane perpendicular to the lengthwise
direction of the fine linear portion is required to be larger than
the cross-sectional area of the cross section obtained by cutting
the rectangular parallelepiped, which has the opening of the
microplasma source and the fine linear portion of the object as
opposite surfaces, by the plane perpendicular to the lengthwise
direction of the fine linear portion. However, in order to obtain
higher formation accuracy, this ratio preferably is roughly ten or
more times greater. If this ratio is smaller than 10 times, then
the activated particles generated by plasma are discharged
outwardly of the fine linear portion of the surface of the
substrate, and the formation accuracy is degraded.
[0128] According to the plasma processing method of the second
embodiment of the present invention, microplasma is generated
inside the space 3 of the microplasma source by supplying electric
power to the member located in the vicinity of the space 3 of the
microplasma source, e.g., the microplasma source while supplying
the gas into the space of the microplasma source arranged in the
vicinity of the substrate 11, and the activated particles
discharged from the opening 10 of the microplasma source joined to
the space 3 act on the substrate 11 to form the fine linear portion
15 on the substrate 11. The gas is flowed through the gas flow
passage provided parallel to the substrate 11 along the lengthwise
direction of the fine linear portion 15, and the fine linear
portion 15 is formed on the object with the activated particles
discharged from the opening 10 narrower than the gas flow passage.
Therefore, the desired fine linear portion 15 can be accurately
processed by plasma.
[0129] Furthermore, according to the plasma processing apparatus of
the second embodiment of the present invention, there are provided
the microplasma source arranged in the vicinity of the substrate
11, the gas supply unit 7 for supplying the plasma generating-use
gas to the microplasma generating-use space 3 of the microplasma
source, and the power supply 12 for supplying electric power to the
member located in the vicinity of the space 3 of the microplasma
source, e.g., the microplasma source. The microplasma
generating-use space 3 of the microplasma source is provided with
the gas flow passage 18 separately from the opening 10 of the
microplasma source, and this gas flow passage 18 communicates with
the gas supply inlet 20 to which the gas is supplied and the gas
exhaust outlet 21, which is provided separately from the opening 10
of the microplasma source located opposite to the substrate 11 and
from which the gas supplied into the gas flow passage 18 is
exhausted. While flowing the gas in the vicinity of the opening 10
parallel to the substrate 11 along the lengthwise direction of the
fine linear portion 15 to be formed on the substrate 11 from the
gas supply inlet 20 toward the gas exhaust outlet 21 inside the gas
flow passage use space 3 of the microplasma source, microplasma is
generated inside the microplasma generating-use space 3 of the
microplasma source, making the activated particles discharged from
the opening 10 of the microplasma source communicating with the
plasma space 3 act on the substrate 11 and forming the fine linear
portion 15 on the substrate 11. The gas flow passage is provided
parallel to the substrate 11 along the lengthwise direction of the
fine linear portion 15. Since the opening 10 is narrower than the
gas flow passage, the desired fine linear portion 15 can be
accurately processed by plasma.
[0130] A third embodiment of the present invention will be
described next with reference to FIGS. 9 through 13.
[0131] FIG. 9 shows a perspective view of a plasma processing
apparatus provided with a microplasma source employed in the third
embodiment of the present invention. FIG. 10 shows a sectional view
cut in the plane A of FIG. 9. FIG. 11A shows a sectional view cut
in the plane F of FIG. 9. Referring to FIGS. 9, 10, and 11A, a
microplasma generating-use space 3 (dot-hatching portion in FIGS.
10 and 11A, hereinafter referred to as a plasma space 3) of a
roughly rectangular parallelepiped configuration for generating
microplasma is formed between two ceramic dielectric plates 1 and
2. Three side portions of the ceramic dielectric plates 1 and 2 are
bonded to ceramic bar-shaped dielectric members 4, 5, and 6, and a
substrate 11, which serves as one example of the object, is
oppositely disposed with interposition of a minute gap on the
remaining one side portion. Gas is supplied from a gas supply unit
7 to a gas flow passage provided parallel to the substrate 11 along
the lengthwise direction of the fine linear portion 15 via a pipe 8
and a slant through hole 20 (one example of the gas supply inlet)
which is formed in the ceramic bar-shaped dielectric member 5 and
inclined toward the substrate 11. The gas is exhausted from the gas
flow passage via a pipe 22 through a slant through hole 21 (one
example of the gas exhaust outlet) which is formed in the ceramic
bar-shaped dielectric member 4 and inclined toward the substrate
11. It is to be noted that the gas flow passage is roughly the same
space as the plasma space 3. By disposing the elongated rectangular
opening 10 of the microplasma source in the vicinity of the
substrate 11 that serves as the object, supplying the gas into the
plasma space 3 and exhausting the gas inside the plasma space 3
from the through hole 21 that functions as a gas exhaust outlet,
the gas is flowed parallel to the substrate 11 along the lengthwise
direction of the opening 10 and in the vicinity of the opening 10.
By supplying high-frequency power of 13.56 MHz from a
high-frequency power supply 12 to a high-frequency electrode 13 and
grounding a grounding electrode 14, plasma is generated in the
plasma space 3, and the activated particles discharged from the
opening 10 of the microplasma source act on the substrate 11,
allowing a fine linear portion 15 to be formed on the surface of
the substrate 11. It is to be noted that the high-frequency
electrode 13 and the grounding electrode 14 are parallel plate
electrodes provided so as to place the plasma space 3 between them.
Moreover, as one example, the width B of the opening 10 of the
microplasma source is 1 mm, and the distance C between the opening
10 of the microplasma source and the substrate 11 is 0.1 mm.
[0132] The microplasma source, which is operable at several pascals
to several times the atmospheric pressure, typically operates
within a range of a pressure of 10000 Pa to about triple the
atmospheric pressure. In particular, the operation at or around the
atmospheric pressure, which requires neither strict sealing
structure nor special exhaust system and appropriately restrains
the diffusion of the plasma and the activated particles, is
especially preferable.
[0133] As one concrete example, a molybdenum thin film, which
served as one example of the fine linear portion 15 formed on the
substrate 11 on the condition that He was supplied by 2000 sccm and
CF.sub.4 was supplied by 4 sccm, as a gas, and high-frequency power
of 30 W was supplied, was subjected to an etching process.
Consequently, an etching profile as shown in FIG. 12 was obtained.
In this case, on the assumption that the depth of the portion most
deeply etched was D and the width of the portion shallower by
D.times.0.8 than the bottom of the pattern was a processing width
E, then E was 0.95 mm. Since the width B of the opening 10 of the
microplasma source was 1 mm, the processing width E was smaller
than this, and the formation accuracy was remarkably improved in
comparison with the prior art example.
[0134] The reason why the formation accuracy is improved as
described above is presumably because the gas is flowed through the
gas flow passage provided parallel to the substrate 11 along the
lengthwise direction of the fine linear portion 15 from the through
hole 20 that functions as a gas supply inlet toward the through
hole 21 that functions as a gas exhaust outlet, and the gas supply
to the gas flow passage and the gas exhaustion from the gas flow
passage are carried out in a space separated from the space brought
in contact with the substrate 11, e.g., in the vicinity of the
midpoint of a distance between the opening 10 of the plasma space 3
on the substrate 11-side in FIG. 11A and the ceramic bar-shaped
dielectric member 6, and therefore, it is made more difficult for
the activated particles generated by the plasma to come in contact
with the substrate surface portion located outside the fine linear
portion 15.
[0135] The pipe 8 is not limited in number to one, and it is
acceptable to provide two pipes 8A and 8B, form two through holes
20 (one example of the gas supply inlet) corresponding to the two
pipes, supply He gas from one pipe 8A and supply a reactant gas
from the other pipe 8B, according to a modification example as
shown in FIG. 11B.
[0136] In the third embodiment of the present invention, as one
example shown in FIG. 13, a cross-sectional area 19 (dot-hatching
portion of FIG. 13) of a cross section obtained by cutting a gas
flow passage (roughly the same space as the plasma space 3) by a
plane perpendicular to the lengthwise direction of the fine linear
portion 15 is twenty-one times as large as a cross-sectional area
17 (rectangular gray portion of FIG. 13) of a cross section
obtained by cutting the rectangular parallelepiped, which has the
opening 10 of the microplasma source and the fine linear portion 15
of the object as opposite, by a plane perpendicular to the
lengthwise direction of the fine linear portion 15. In order to
improve the formation accuracy, the cross-sectional area of the
cross section obtained by cutting the gas flow passage by the plane
perpendicular to the lengthwise direction of the fine linear
portion is required to be larger than the cross-sectional area of
the cross section obtained by cutting the rectangular
parallelepiped, which has the opening of the microplasma source and
the fine linear portion of the object as opposite surfaces, by the
plane perpendicular to the lengthwise direction of the fine linear
portion. However, in order to obtain higher formation accuracy,
this ratio preferably is roughly ten or more times greater. If this
ratio is smaller than 10 times, then the activated particles
generated by plasma are discharged outwardly of the fine linear
portion of the surface of the substrate, and the formation accuracy
is degraded.
[0137] According to the plasma processing method of the
above-mentioned third embodiment of the present invention,
microplasma is generated inside the space 3 of the microplasma
source by supplying electric power to the member located in the
vicinity of the space 3 of the microplasma source, e.g., the
microplasma source while supplying the gas into the space 3 of the
microplasma source arranged in the vicinity of the substrate 11,
and the activated particles discharged from the opening 10 of the
microplasma source joined to the space 3 act on the substrate 11 to
form the fine linear portion 15 on the surface of the substrate 11.
The gas is flowed through the gas flow passage provided parallel to
the substrate 11 along the lengthwise direction of the fine linear
portion 15, the gas supply to the gas flow passage and the gas
exhaustion from the gas flow passage are carried out in the space
separated from the space 3 brought in contact with the substrate
11. Therefore, the desired fine linear portion 15 can be accurately
processed by plasma.
[0138] Furthermore, according to the plasma processing apparatus of
the plasma processing apparatus of the seventh inventive aspect of
the present application, there are provided the microplasma source
disposed in the vicinity of the substrate 11, the gas supply unit 7
for supplying the plasma generating-use gas to the microplasma
generating-use space 3 of the microplasma source, and the power
supply 12 for supplying electric power to the member located in the
vicinity of the plasma space 3 of the microplasma source, e.g., the
microplasma source. The microplasma generating-use space 3 of the
microplasma source communicates with the gas supply inlet 20, which
is arranged separately from the opening 10 of the microplasma
source and supplied with the gas to its portion separated from the
opening 10 of the microplasma generating-use space 3 and the gas
exhaust outlet 21, which is arranged separately from the opening 10
of the microplasma source and from which the gas supplied into the
plasma generating-use space 3 is exhausted. The microplasma is
generated inside the microplasma generating-use space 3 of the
microplasma source while flowing the gas parallel to the substrate
11 along the lengthwise direction of the fine linear portion 15 to
be formed on the substrate 11 and in the vicinity of the opening 10
from the gas supply inlet 20 toward the gas exhaust outlet 21 in
the portion located apart from the opening 10 of the microplasma
generating-use space 3 of the microplasma source, and the activated
particles discharged from the opening 10 of the microplasma source
communicating with the microplasma generating-use space 3 act on
the substrate 11, thereby forming the fine linear portion 15 on the
substrate 11. Since the gas flow passage communicating with the gas
supply inlet 20 for carrying out the gas supply and the gas exhaust
outlet 21 for carrying out the gas exhaustion is formed separately
from the microplasma generating-use space 3 located in the vicinity
of the substrate 11. Therefore, the desired fine linear portion 15
can be accurately processed by plasma.
[0139] A fourth embodiment of the present invention will be
described next with reference to FIGS. 14 through 17.
[0140] FIG. 14 shows a perspective view of a plasma processing
apparatus provided with a microplasma source employed in the fourth
embodiment of the present invention. FIG. 15 shows a sectional view
cut in the plane A of FIG. 14. FIG. 16 shows a sectional view cut
in the plane F of FIG. 14. Referring to FIGS. 14, 15, and 16, a
microplasma generating-use space 3 (dot-hatching portion of FIGS.
15 and 16, hereinafter referred to as a plasma space 3) of a
roughly rectangular parallelepiped shape for generating microplasma
is formed between two ceramic dielectric plates 1 and 2. Three side
portions of the ceramic dielectric plates 1 and 2 are bonded to
ceramic bar-shaped dielectric members 4, 5, and 6, and a substrate
11, which serves as one example of the object, is oppositely
disposed with interposition of a minute gap on the remaining one
side portion. Gas is supplied from a gas supply unit 7 to the
plasma space 3 via a pipe 8 and a slant through hole 20 (one
example of the gas supply inlet) which is formed in the ceramic
bar-shaped dielectric member 5 and inclined toward the substrate
11. The gas is exhausted from a pipe 22 via a through hole 23 (one
example of the gas exhaust outlet) which is formed from the plasma
space 3 in an approximate center portion of the ceramic bar-shaped
dielectric member 6 so as to extend in a direction perpendicular to
the surface of the substrate 11 toward the side opposite from the
substrate 11. By arranging an elongated rectangular opening 10 of
the microplasma source in the vicinity of the substrate 11 that
serves as the object, so that the gas inside the plasma space 3 is
exhausted toward the side opposite from the substrate 11 from the
through hole 23 of the ceramic bar-shaped dielectric member 6 while
gas is supplied into the plasma space 3 from the through hole 20 of
the ceramic bar-shaped dielectric member 5 to flow the gas parallel
to the substrate 11 along the lengthwise direction of the opening
10 in the vicinity of the opening 10. By supplying high-frequency
power of 13.56 MHz from a high-frequency power supply 12 to a
high-frequency electrode 13 and grounding a grounding electrode 14,
plasma is generated in the plasma space 3, and the activated
particles discharged from the opening 10 of the microplasma source
act on the substrate 11, allowing a fine linear portion 15 to be
formed on the surface of the substrate 11. It is to be noted that
the high-frequency electrode 13 and the grounding electrode 14 are
parallel plate electrodes provided so as to place the plasma space
3 between them. Moreover, as one example, the width B of the
opening 10 of the microplasma source is 1 mm, and the distance C
between the opening 10 of the microplasma source and the substrate
11 is 0.1 mm. The place of the through hole 23 is not limited to
the approximate center portion of the ceramic bar-shaped dielectric
member 6, and it is acceptable to form the through hole 23 in an
arbitrary portion so long as the portion is apart from the through
hole 20.
[0141] The microplasma source, which is operable at several pascals
to several times the atmospheric pressure, typically operates
within a range of a pressure of 10000 Pa to about triple the
atmospheric pressure. In particular, the operation at or around the
atmospheric pressure, which requires neither strict sealing
structure nor special exhaust unit and appropriately restrains the
diffusion of the plasma and the activated particles, is especially
preferable.
[0142] As one concrete example, a molybdenum thin film, which
served as one example of the fine linear portion 15 formed on the
substrate 11 on the condition that He was supplied by 2000 sccm and
CF.sub.4 was supplied by 4 sccm, as a gas, and high-frequency power
of 30 W was supplied, was subjected to an etching process.
Consequently, an etching profile as shown in FIG. 17 was obtained.
In this case, on the assumption that the depth of the portion most
deeply etched was D and the width of the portion shallower by
D.times.0.8 than the bottom of the pattern was a processing width
E, then E was 0.79 mm. Since the width B of the opening 10 of the
microplasma source was 1 mm, the processing width E was smaller
than this, and the formation accuracy was remarkably improved in
comparison with the prior art example.
[0143] The reason why the formation accuracy is improved as
described above is presumably because the gas supply to the plasma
space 3 is carried out from the through hole 20 that serves as a
minute hole provided for the ceramic bar-shaped dielectric member 5
that serves as one example of wall surfaces that surround the
plasma space 3, and the gas exhaustion from the plasma space 3 is
carried out through the plasma space 3 from the through hole 23
formed in the ceramic bar-shaped dielectric member 6 in the
direction opposite from the substrate 11, and therefore, it is made
more difficult for the activated particles generated by the plasma
to come in contact with the substrate surface portion located
outside the fine linear portion 15. One example of the through hole
20 that serves as the minute hole has a diameter of not greater
than 1 mm or more preferably has a diameter of 0.2 mm to 0.5
mm.
[0144] According to the plasma processing method of the fourth
embodiment of the present invention, microplasma is generated in
the microplasma generating-use space 3 of the microplasma source by
supplying electric power to the member located in the vicinity of
the microplasma generating-use space 3 of the microplasma source
(e.g., at least one of the electrode provided on the side opposite
from the surface to be processed of the substrate 11, the substrate
11, and the microplasma source) while supplying the gas into the
microplasma generating-use space 3 of the microplasma source
arranged in the vicinity of the substrate 11, and the activated
particles discharged from the opening 10 of the microplasma source
joined to the microplasma generating-use space 3 act on the
substrate 11 to form the fine linear portion 15 on the substrate
11. By carrying out the gas supply to the microplasma
generating-use space 3 for generating the microplasma from the
through hole 20 provided at the wall surface 5 that surrounds the
microplasma generating-use space 3 for generating the microplasma
and carrying out the gas exhaustion from the microplasma
generating-use space 3 for generating the microplasma through the
microplasma generating-use space 3 for generating the microplasma
oppositely from the side on which the fine linear portion 15 of the
substrate 11 is arranged. By this operation, the fine linear
portion 15 is formed on the substrate 11 while flowing the gas
parallel to the substrate 11 along the lengthwise direction of the
fine linear portion 15 and in the vicinity of the opening 10.
Therefore, the desired fine linear portion 15 can be accurately
processed by plasma.
[0145] According to the plasma processing apparatus of the fourth
embodiment of the present invention, there are provided the
microplasma source disposed in the vicinity of the substrate 11,
the gas supply unit 7 for supplying the plasma generating-use gas
to the microplasma generating-use space 3 of the microplasma
source, and the power supply 12 for supplying electric power to the
member located in the vicinity of the plasma space 3 of the
microplasma source (e.g., at least one of the electrode provided on
the side opposite from the surface to be processed of the substrate
11, the substrate 11, and the microplasma source). The microplasma
generating-use space 3 of the microplasma source communicates with
the gas supply inlet 20 to which the gas is supplied and the gas
exhaust outlet 23, which is provided separately from the opening 10
of the microplasma source opposite to the substrate 11 and from
which the gas supplied into the microplasma generating-use space 3
is exhausted. The microplasma is generated inside the microplasma
generating-use space 3 of the microplasma source while flowing the
gas parallel to the substrate 11 along the lengthwise direction of
the fine linear portion 15 to be formed on the substrate 11 and in
the vicinity of the opening 10 from the gas supply inlet 20 toward
the gas exhaust outlet 23 inside the microplasma generating-use
space 3 of the microplasma source to make the activated particles
discharged from the opening 10 of the microplasma source
communicating with the microplasma generating-use space 3 act on
the substrate 11, thereby forming the fine linear portion 15 on the
substrate 11. The gas supply to the microplasma generating-use
space 3 for generating the microplasma by means of the gas supply
unit 7 is carried out from the through hole 20 provided at the
ceramic bar-shaped dielectric member 5 that surrounds the
microplasma generating-use space 3 for generating microplasma, and
the gas exhaustion from the microplasma generating-use space 3 for
generating the microplasma is carried out through the microplasma
generating-use space 3 for generating the microplasma oppositely
from the opening 10 of the microplasma source. Therefore, the
desired fine linear portion 15 can be accurately processed by
plasma.
[0146] Although there has been exemplarily described the case where
the high-frequency power is supplied across the parallel plate
electrodes 1 and 2 provided so as to place the space 3 for
generating the microplasma between them in the first through fourth
embodiments of the present invention, the present invention is not
limited to the above-mentioned system. For example, as in the fifth
embodiment of the present invention shown in FIGS. 18 and 19, it is
also possible to supply high-frequency power across the grounded
object 11 to be processed and an electrode 24 opposite to the
object 11 to be processed that is a conductor as one example of the
member located in the vicinity of the space 3 of the microplasma
source, via the space 3 for generating the microplasma. In this
case, each of the parallel plate electrodes 14, which are provided
in the upper and lower portions in FIG. 19 so as to place the space
3 for generating microplasma between them, is a grounding
electrode. The other construction is similar to that of the first
embodiment of the present invention, and therefore, no description
is herein provided therefor. It is to be noted that FIG. 19 is a
sectional view cut in the plane A of FIG. 18.
[0147] Otherwise, as in the sixth embodiment of the present
invention shown in FIGS. 20 through 21, it is possible to supply
high-frequency power across an electrode 24 opposite to the object
11 to be processed, which is a dielectric substance, via the space
3 for generating microplasma, and the electrodes 25, which is
provided as one example of the member located in the vicinity of
the space 3 of the microplasma source on the side opposite from the
surface to be processed of the substrate 11 with interposition of a
gap or in contact. In this case, each of the parallel plate
electrodes 14, which are provided so as to place the microplasma
generating-use space 3 between them, is a grounding electrode. The
other construction is similar to that of the first embodiment of
the present invention, and therefore, no description is herein
provided therefor. It is to be noted that FIG. 21 is a sectional
view cut in the plane A of FIG. 20.
[0148] There have been exemplarily described the case where the
parallel plate electrodes 14 provided with interposition of the
space 3 for generating microplasma are grounded in the fifth or
sixth embodiment of the present invention. By adopting the
above-mentioned arrangement, there is the effect of suppressing the
diffusion of plasma to the portion other than the space 3 for
generating microplasma. However, depending on the dimensions of
components and the type of gas, in some cases, the microplasma can
be generated without trouble even if the parallel plate electrodes
14 are removed.
[0149] Moreover, although there has been exemplarily described the
case where the gas is supplied from the gas supply unit 7 to the
plasma space 3 via the pipe 8 and the slant through hole 20 formed
in the ceramic bar-shaped dielectric member 5 in the fourth
embodiment of the present invention. However, as described in
connection with the seventh embodiment of the present invention
shown in FIG. 22, it is acceptable to carry out gas supply through
a gas flow passage (one example of the gas supply inlet)
constructed of a through hole provided at the one flat plate
electrode 13 of the parallel plate electrodes 13 and 14
penetratively to the plasma space 3 and a through hole provided at
the ceramic dielectric plate 1. In this case, a through hole that
serves as a gas flow passage is provided inside the high-frequency
electrode 13, and the gas is supplied to the plasma space 3 from
the gas supply unit 7 via the above through hole and the through
hole provided at the ceramic dielectric plate 1 communicating with
the through hole. The other construction is similar to that of the
fourth embodiment of the present invention, and therefore, no
description is herein provided therefor. Of course, conversely to
this, it is acceptable to provide a construction in which a through
hole as a gas flow passage is provided at the grounding electrode
14 and the gas is supplied to the plasma space 3 from the gas
supply unit 7 via the above through hole and a through hole
provided at the ceramic dielectric plate 2 communicating with the
through hole.
[0150] Although there has been exemplarily described the case where
the parallel plate capillary type is employed as a microplasma
source in the aforementioned first through seventh embodiments of
the present invention, it is possible to employ a variety of
microplasma sources of another system capillary type such as an
inductive coupling capillary type, a micro gap system, an inductive
coupling tube types and so on.
[0151] Moreover, by supplying a DC voltage or high-frequency power
to the object to be processed, or the electrode provided on the
side opposite from the surface to be processed of the object to be
processed, the action of guiding ions in microplasma or, in other
words, activated particles so that the activated particles come in
contact with the fine linear portion 15 of the substrate 11 can be
enhanced.
[0152] Moreover, there has been exemplarily described the case
where the molybdenum thin film on the substrate 11 is subjected to
the plasma processing by an etching process. However, the object to
be subjected to the plasma processing is not limited to them, and
the present invention can be applied to the plasma processing of a
variety of substrates (for example, substrate whose surface to be
processed is a flat surface) or to the plasma processing of an
object to be processed coated with a variety of films (for example,
plasma processing of a flat surface coated with a variety of films
of the object to be processed). The object to be processed is not
limited to a substrate of a dielectric substance and is allowed to
be an arbitrary member constructed of a material other than the
dielectric substance. Moreover, it is possible to carry out plasma
processing by etching with a photoresist, a resin represented by
polyimide, or the like using a mixed gas of He and O.sub.2.
Moreover, it is possible to subject a sheet-shaped object to be
processed to plasma processing by continuous etching processing of
the object into a fine linear shape while the object is being
conveyed by a roll-to-roll system. Otherwise, the plasma processing
can be carried out on the surface of a variety of objects to be
processed by thin film deposition according to the plasma CVD
method.
[0153] Moreover, the fine linear portion 15 of the substrate 11 is
not limited to the thin film formed in the recess of the substrate
11 as illustrated in connection with the aforementioned embodiments
and is allowed to be a thin film as a protruding portion
protrudingly formed on the surface of the substrate 11.
[0154] Moreover, although there has been exemplarily described the
case where the microplasma is generated by the high-frequency power
of 13.56 MHz, the microplasma can be generated by using
high-frequency power within a range of several hundred kilohertz to
several gigahertz. It is otherwise possible to generate
high-efficiency plasma by supplying pulse power while restraining
shift to arc discharge.
[0155] Moreover, although there has been exemplarily described the
case where the width of the opening 10 of the microplasma source is
1 mm, the width of the opening 10 of the microplasma source is not
limited to this and preferably is roughly not smaller than 0.01 mm
and not greater than 5 mm. The reason why the width of the opening
10 is not greater than 5 mm is that the activated particles
generated by plasma highly possibly come in contact with the
outside of the fine linear portion of the substrate surface when
the width exceeds 5 mm, failing in processing by plasma only the
region limited to the fine linear portion 15. Furthermore, the
width of the opening of the microplasma source more preferably is
not smaller than 0.01 mm and not greater than 1 mm. The reason why
the width of the opening 10 is not greater than 1 mm is that the
activated particles generated by plasma become hard to come in
contact with the outside of the fine linear portion 15 on the
surface of the substrate 11 as the width of the opening 10 of the
microplasma source is smaller, providing an advantage that only the
region limited to the fine linear portion 15 can be more reliably
subjected to the plasma processing. On the other hand, considering
the accuracy of the plasma processing of the components that
constitute the microplasma source and a change in shape with the
lapse of time and so on due to repetitive processing, the width is
prevented from being extremely reduced. Therefore, the width of the
opening 10 preferably is not smaller than 0.01 mm.
[0156] Moreover, although there has been exemplarily described the
case where the distance between the opening 10 of the microplasma
source and the object to be processed, e.g., the substrate 11 is
0.1 mm, the distance between the opening 10 of the microplasma
source and the object to be processed is not limited to this and
preferably is roughly not smaller than 0.01 mm and not greater than
1 mm. The reason why the above-mentioned distance is not greater
than 1 mm is that the activated particles generated by plasma
highly possibly come in contact with the outside of the fine linear
portion of the substrate surface when the distance exceeds 1 mm,
failing in processing by plasma only the region limited to the fine
linear portion. Furthermore, the distance between the opening of
the microplasma source and the object to be processed more
preferably is not smaller than 0.01 mm and not greater than 0.5 mm.
The reason why the above-mentioned distance is not greater than 0.5
mm is that the activated particles generated by plasma become hard
to come in contact with the outside of the fine linear portion on
the surface of the substrate as the distance between the opening of
the microplasma source and the object to be processed is smaller,
providing an advantage that only the region limited to the fine
linear portion can be more reliably subjected to the plasma
processing. On the other hand, considering the accuracy of the
plasma processing of the components that constitute the microplasma
source, a change in shape with the lapse of time due to repetitive
processing, and further the reproducibility and stability of the
distance between the opening of the microplasma source and the
object to be processed, the distance is prevented from being
extremely reduced. Therefore, the distance is considered to be
preferably not smaller than 0.01 mm.
[0157] In the aforementioned respective embodiments, it is
acceptable to reverse the direction of gas supply and exhaustion by
making the gas supply inlet function as a gas exhaust outlet and
making the gas exhaust outlet as a gas supply inlet.
[0158] Moreover, in the aforementioned respective embodiments, if
the gas supplied from the gas supply inlets 9 and 20 to the space 3
or the gas flow passage is exhausted by 70% or more in terms of the
supply flow rate from the gas exhaust outlet 90, then the gas can
be more reliably prevented from being exhausted from the opening 10
to allow the activated particles to be prevented from effusing from
the opening 10, making it possible to prevent the plasma processing
from being carried out in a wide range beyond the desired fine
linear portion 15.
[0159] As is apparent from the above description, according to the
plasma processing method of the first inventive aspect of the
present application, microplasma is generated in the space of the
microplasma source by supplying electric power to the member (e.g.,
at least one of the electrode provided on the side opposite from
the surface to be processed of the object to be processed, the
object to be processed, and the microplasma source) located in the
vicinity of the space of the microplasma source while supplying the
gas into the space of the microplasma source arranged in the
vicinity of the object to be processed, and the activated particles
discharged from the opening of the microplasma source joined to the
space act on the object to be processed, forming the fine linear
portion on the object to be processed. Accordingly, the fine linear
portion is formed on the object to be processed while flowing the
gas parallel to the object to be processed along the lengthwise
direction of the fine linear portion and in the vicinity of the
opening. Therefore, the desired fine linear portion can be
accurately processed by plasma.
[0160] Moreover, according to the plasma processing method of the
second inventive aspect of the present application, microplasma is
generated in the space of the microplasma source by supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source while supplying the gas into the space of the
microplasma source arranged in the vicinity of the object to be
processed, and the activated particles discharged from the opening
of the microplasma source joined to the space act on the object to
be processed, forming the fine linear portion on the object to be
processed. Accordingly, the fine linear portion is formed on the
object to be processed while flowing the gas through the gas flow
passage provided parallel to the object to be processed along the
lengthwise direction of the fine linear portion and discharging the
activated particles from the opening narrower than the gas flow
passage. Therefore, the desired fine linear portion can be
accurately processed by plasma.
[0161] Moreover, according to the plasma processing method of the
third inventive aspect of the present application, microplasma is
generated in the space of the microplasma source by supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source while supplying the gas into the space of the
microplasma source arranged in the vicinity of the object to be
processed, and the activated particles discharged from the opening
of the microplasma source joined to the space act on the object to
be processed, forming the fine linear portion on the object to be
processed. Accordingly, the fine linear portion is formed on the
object to be processed while flowing the gas through the gas flow
passage provided parallel to the object to be processed along the
lengthwise direction of the fine linear portion and carrying out
the gas supply to the gas flow passage and the gas exhaustion from
the gas flow passage in the space separated from the space to be
brought in contact with the object to be processed. Therefore, the
desired fine linear portion can be accurately processed by
plasma.
[0162] Moreover, according to the plasma processing method of the
fourth inventive aspect of the present application, microplasma is
generated in the space of the microplasma source by supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source while supplying the gas into the space of the
microplasma source arranged in the vicinity of the object to be
processed, and the activated particles discharged from the opening
of the microplasma source joined to the space act on the object to
be processed, forming the fine linear portion on the object to be
processed. Accordingly, the fine linear portion is formed on the
object to be processed while flowing the gas parallel to the object
to be processed along the lengthwise direction of the fine linear
portion and in the vicinity of the opening by carrying out the gas
supply to the space for generating microplasma from the through
hole provided at the wall surface that surrounds the space for
generating microplasma and carrying out the gas exhaustion from the
space for generating microplasma through the space for generating
microplasma in the direction opposite from the side on which the
fine linear portion of the object to be processed is disposed.
Therefore, the desired fine linear portion can be accurately
processed by plasma.
[0163] Moreover, according to the plasma processing apparatus of
the fifth inventive aspect of the present application, there are
provided the microplasma source arranged in the vicinity of the
object to be processed, the gas supply unit for supplying the
plasma generating-use gas to the space of the microplasma source
and the power supply for supplying electric power to the member
(e.g., at least one of the electrode provided on the side opposite
from the surface to be processed of the object to be processed, the
object to be processed, and the microplasma source) located in the
vicinity of the space of the microplasma source. The
above-mentioned space of the microplasma source communicates with
the gas supply inlet to which the gas is supplied and the gas
exhaust outlet, which is provided separately from the opening of
the microplasma source opposite to the object to be processed and
from which the gas supplied into the space is exhausted. The
microplasma is generated inside the space of the microplasma source
while flowing the gas parallel to the object to be processed along
the lengthwise direction of the fine linear portion to be formed on
the object to be processed and in the vicinity of the opening from
the gas supply inlet toward the gas exhaust outlet in the space of
the microplasma source to make the activated particles discharged
from the opening of the microplasma source communicating with the
space act on the object to be processed, thereby forming the fine
linear portion on the object to be processed. Therefore, the
desired fine linear portion can be accurately processed by
plasma.
[0164] Moreover, according to the plasma processing apparatus of
the sixth inventive aspect of the present application, there are
provided the microplasma source arranged in the vicinity of the
object to be processed, the gas supply unit for supplying the
plasma generating-use gas to the microplasma generating-use space
of the microplasma source, and the power supply for supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source. The microplasma generating-use space of the
microplasma source is provided with a gas flow passage space
separately from the opening of the microplasma source, and this gas
flow passage space communicates with the gas supply inlet to which
the gas is supplied and the gas exhaust outlet, which is provided
separately from the opening of the microplasma source opposite to
the object to be processed and from which the gas supplied into the
gas flow passage space is exhausted. The microplasma is generated
inside the microplasma generating-use space of the microplasma
source while flowing the gas parallel to the object to be processed
along the lengthwise direction of the fine linear portion to be
formed on the object to be processed and in the vicinity of the
opening from the gas supply inlet toward the gas exhaust outlet in
the gas flow passage space of the microplasma source to make the
activated particles discharged from the opening of the microplasma
source communicating with the space act on the object to be
processed, forming the fine linear portion on the object to be
processed. The gas flow passage is provided parallel to the object
to be processed along the lengthwise direction of the fine linear
portion, and the opening is narrower than the gas flow passage.
Therefore, the desired fine linear portion can be accurately
processed by plasma.
[0165] Moreover, according to the plasma processing apparatus of
the seventh inventive aspect of the present application, there are
provided the microplasma source arranged in the vicinity of the
object to be processed, the gas supply unit for supplying the
plasma generating-use gas to the microplasma generating-use space
of the microplasma source, and the power supply for supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source. The microplasma generating-use space of the
microplasma source communicates with the gas supply inlet, which is
arranged separately from the opening of the microplasma source and
through which the gas is supplied to a portion located apart from
the opening in the microplasma generating-use space and the gas
exhaust outlet, which is arranged separately from the opening of
the microplasma source and from which the gas supplied into the
microplasma generating-use space is exhausted. The microplasma is
generated inside the microplasma generating-use space of the
microplasma source while flowing the gas parallel to the object to
be processed, along the lengthwise direction of the fine linear
portion to be formed on the object to be processed, in the vicinity
of the opening, from the gas supply inlet toward the gas exhaust
outlet in a portion separately from the opening in the microplasma
generating-use space of the microplasma source to make the
activated particles discharged from the opening of the microplasma
source communicating with the space act on the object to be
processed, forming the fine linear portion on the object to be
processed. Accordingly, the gas flow passage, which communicates
with the gas supply inlet for carrying out the gas supply and the
gas exhaust outlet for carrying out the gas exhaustion, is formed
separately from the microplasma generating-use space located
adjacent to the object to be processed. Therefore, the desired fine
linear portion can be accurately processed by plasma.
[0166] Moreover, according to the plasma processing apparatus of
the eighth inventive aspect of the present application, there are
provided the microplasma source arranged in the vicinity of the
object to be processed, the gas supply unit for supplying the
plasma generating-use gas to the microplasma generating-use space
of the microplasma source, and the power supply for supplying
electric power to the member (e.g., at least one of the electrode
provided on the side opposite from the surface to be processed of
the object to be processed, the object to be processed, and the
microplasma source) located in the vicinity of the space of the
microplasma source. The microplasma generating-use space of the
microplasma source communicates with the gas supply inlet to which
the gas is supplied and the gas exhaust outlet, which is arranged
separately from the opening of the microplasma source located
opposite from the microplasma generating-use space and from which
the gas supplied into the microplasma generating-use space is
exhausted. The microplasma is generated inside the microplasma
generating-use space of the microplasma source while flowing the
gas parallel to the object to be processed, along the lengthwise
direction of the fine linear portion to be formed on the object to
be processed, in the vicinity of the opening, from the gas supply
inlet toward the gas exhaust outlet in the microplasma
generating-use space of the microplasma source to make the
activated particles discharged from the opening of the microplasma
source communicating with the microplasma generating-use space act
on the object to be processed, forming the fine linear portion on
the object to be processed. Accordingly, the gas supply to the
microplasma generating-use space for generating the microplasma by
the gas supply unit is carried out from the through hole provided
at the wall surface that surrounds the microplasma generating-use
space for generating the microplasma, and the gas exhaustion from
the microplasma generating-use space for generating the microplasma
is carried out through the microplasma generating-use space for
generating the microplasma in the direction opposite from the
opening of the microplasma source. Therefore, the desired fine
linear portion can be accurately processed by plasma.
[0167] The plasma processing methods and apparatuses of the eighth
through tenth embodiments of the present invention, which are able
to form a pattern by processing a minute region at low cost without
using a mask pattern in addition to the aforementioned object, will
be described below.
[0168] Before describing the contents of the eighth through tenth
embodiments, prior art techniques will be described first.
[0169] As a prior art plasma processing apparatus, there are known
ones disclosed in, for example, Japanese Unexamined Patent
Publication No. 2000-164395 and Japanese Unexamined Patent
Publication No. 9-27482.
[0170] Explaining the substrate electrode plasma generating
apparatus disclosed in Japanese Unexamined Patent Publication No.
2000-164395 with reference to FIG. 32, the apparatus is constructed
of an array of minute-gap thin-film electrode pairs 101, 102, 103,
and 104 formed by sputter deposition of tungsten on a silicon
substrate 105 whose surface is oxidized and thereafter dry etching
the same. Plasma is generated on the minute-gap thin-film electrode
pairs 101, 102, 103, and 104 by supplying high-frequency power to
the minute-gap thin-film electrode pairs 101, 102, 103, and 104
disposed on the silicon substrate 105, and plasma processing such
as etching, deposition, surface reforming, or the like is carried
out.
[0171] Explaining the plasma etching apparatus using microwave
disclosed in Japanese Unexamined Patent Publication No. 9-27482
with reference to FIG. 33, microwave of 2.45 GHz generated by a
magnetron 111 is applied to a mixed gas of CF.sub.4 and oxygen that
are passing through a reactive gas supply pipe 113 via a waveguide
112, making plasma of the reactive gas. The reactive gas put in the
plasma state is applied from a nozzle 114 to a projecting portion
115a of a wafer 115, and the projecting portion 115a is etched. A
reaction product generated during etching is sucked from a suction
port of a reaction product discharge pipe 116 provided coaxially
around the periphery of the reactive gas supply pipe 113 and then
exhausted to the outside.
[0172] Moreover, in order to locally etch the surface of the wafer
115, there is provided a construction in which the wafer 115 is
fixed by suction to a movable carriage 117, and the movable
carriage 117 is moved in the X, Y, and .theta. directions by a
drive means 118.
[0173] However, the aforementioned conventional systems have an
issue that the plasma processing for forming a pattern by
processing a minute region at low cost is difficult.
[0174] In the substrate electrode plasma generating apparatus of
FIG. 32, only the region located adjacent to the array of the
minute-gap thin-film electrode pairs 101 through 104 provided on
the silicon substrate 105 can be processed by plasma. Therefore, in
order to form the desired pattern, it is required to form
minute-gap thin-film electrode pairs in correspondence with the
pattern, and it is required to carry out patterning of the
minute-gap thin-film electrode pairs instead of using a mask
pattern, disadvantageously requiring extra cost by that much.
[0175] In the plasma etching apparatus of FIG. 33, only radicals
among the particles existing in the generated plasma diffuse
outwardly of a nozzle 114 separately from the plasma, and
therefore, processing is to be carried out mainly by radicals in
this kind of apparatus. The processing mainly using only radicals,
which can also be applied to the processing of the entire surface
of the object to be processed, cannot be applied to the processing
of a part of the object to be processed. This is presumably because
the radicals diffuse isotropically similarly to gas. Therefore, in
order to apply this kind of apparatus to the process for forming a
pattern by processing a minute region, it is required to use a mask
pattern, and this leads to an issue that a process for forming a
pattern by processing a minute region at low cost is difficult.
[0176] In view of the aforementioned conventional issues, the
eighth through tenth embodiments of the present invention have the
object of providing a plasma processing apparatus and method
capable of forming a pattern by processing a minute region at low
cost without using a mask pattern.
[0177] A plasma processing apparatus and method according to the
eighth embodiment of the present invention will be described below
with reference to FIGS. 27 through 29D.
[0178] Referring to FIG. 27, reference numeral 201 denotes a first
electrode, and 202 denotes a second electrode, which are oppositely
arranged so as to form a discharge space S for generating plasma
discharge between the first electrode 201 and the second electrode
202, constituting a plasma generating section 245. By connecting a
high-frequency power supply 203 to the first electrode 201,
applying high-frequency power to the first electrode 201, and
grounding the second electrode 202, plasma discharge is started in
the discharge space S of the plasma generating section 245. A gas
supply inlet 204 is provided at one end of the discharge space S
located between the first electrode 201 and the second electrode
202 and connected to a gas supply unit 206 via a gas pipe 205,
allowing gas to flow through the discharge space S. An opening 207
for carrying out plasma processing is provided at the other end of
the discharge space S. By holding (or holding by suction) a
substrate 208 as an object to be processed by means of a substrate
holding stage 240 constructed of an X-Y stage provided with a
suction function or the like as one example of an object moving
unit adjacently to the opening 207, the substrate 208 is subjected
to various plasma processing of etching, film formation, surface
reforming, and so on.
[0179] The first electrode 201 and the second electrode 202, which
constitute the plasma generating section 245, are both fixed to a
stage 209. The stage 209 of the plasma generating section 245 is
connected to a plasma generating section moving unit 210 that can
perform three-dimensional position control, and the plasma
generating section moving unit 210 is connected to a plasma
processing control unit 241. The plasma processing control unit 241
is connected to a high-frequency power supply 203, a gas supply
unit 206, a memory 242 that stores various sorts of plasma
processing information of the substrate 208, and the substrate
holding stage 240. On the basis of the various sorts of plasma
processing information stored in the memory 242, application
control of the high-frequency power to the first electrode 201 from
the high-frequency power supply 203, gas supply control by the gas
supply unit 206, and position control (further substrate position
control by the substrate holding stage 240 at need) of the plasma
generating section 245 by the plasma generating section moving unit
210 are carried out respectively. According to this operation, by
moving the stage 209 while carrying out the plasma processing, the
plasma processing can be performed automatically at an arbitrary
plasma density throughout the specified region.
[0180] In this case, in order to drive the plasma generating
section 245 while three-dimensionally controlling the same, the
plasma generating section moving unit 210 is constructed of
position control mechanisms 224, 225, and 226, each of which can
perform one-dimensional position control. As shown in FIG. 28,
these position control mechanisms 224, 225, and 226 are each
constructed so that a stage 221 is movably supported by a rail
guide 222 that has a bearing and meshed with a ball thread 222a
arranged along the rail guide 222, and by forwardly and reversely
driving the ball thread 222a by means of a drive unit 223 that has
a reversibly driven servomotor 223A and a reduction gear 223B, the
stage 221 advances and retreats. With this arrangement, the plasma
generating section moving unit 210 can be driven respectively and
independently in an X-axis direction (direction penetrating the
sheet plane of FIG. 27), a Y-axis direction (lateral direction in
FIG. 27) perpendicular to the X-axis direction, and a Z-axis
direction (up-and-down direction in FIG. 27) perpendicular to the
Y-axis direction. In this case, the plasma generating section
moving unit 210 is constructed of an X-axis direction position
control mechanism 226 that functions as an X-axis direction drive
unit for advancing and retreating the stage 221 in the X-axis
direction, a Y-axis direction position control mechanism 225 that
functions as a Y-axis direction drive unit for advancing and
retreating the stage 221 in the Y-axis direction, and a Z-axis
direction position control mechanism 224 that functions as a Z-axis
direction drive unit for advancing and retreating the stage 221.in
the Z-axis direction. Then, by fixing the Y-axis direction position
control mechanism 225 to the stage 221 of the Z-axis direction
position control mechanism 224, fixing the X-axis direction
position control mechanism 226 to the stage 221 of the Y-axis
direction position control mechanism 225, and fixing the stage 209
to the stage 221 of the X-axis direction position control mechanism
226, the first electrode 201 and the second electrode 202 supported
on the stage 209 can advance and retreat independently in the X-,
Y-, and Z-axis directions, respectively, by the X-axis direction
position control mechanism 226, the Y-axis direction position
control mechanism 225, and the Z-axis direction position control
mechanism 224.
[0181] A plasma intermissive generation control unit 211 is
provided between the first electrode 201 and the high-frequency
power supply 203, so that the region where plasma processing is
carried out and the region where plasma processing is not carried
out can be controlled when the stage 209 is moved. The plasma
intermissive generation control unit 211 is connected to a plasma
processing control unit 241 and executes operation so as to control
the high-frequency power applied to the first electrode 201 from
the high-frequency power supply 203 on the basis of, for example,
the position information of the plasma generating section 245 from
the X-axis direction position control mechanism 226, the Y-axis
direction position control mechanism 225, and the Z-axis direction
position control mechanism 224 and the position information of the
region where plasma processing is carried out and the region where
plasma processing is not carried out concerning the substrate 208
stored in the memory 242. As a result, plasma is generated by
applying the high-frequency power from the high-frequency power
supply 203 to the first electrode 201 only when the plasma
generating section 245 is located above the region where the plasma
processing of the substrate 208 is carried out, so that the plasma
processing is carried out in the region where plasma processing is
carried out. When the plasma generating section 245 is located
above the region where plasma processing of the substrate 208 is
not carried out, the high-frequency power is not applied from the
high-frequency power supply 203 to the first electrode 201, so that
the plasma processing is not carried out in the region where plasma
processing is not carried out.
[0182] This will be described in detail with reference to FIGS. 29A
through 29D. First of all, as shown in FIG. 29A, by generating
plasma 231 in a discharge space S between the first electrode 201
and the second electrode 202 of the plasma generating section 245
and putting this plasma 231 close to the substrate 208, the plasma
processing can be carried out on a plasma processing region 232 of
the substrate 208. Next, as shown in FIG. 29B, by relativity moving
the plasma 231 one-dimensionally or two-dimensionally to the
substrate 208, the plasma processing area 232 can be a line.
Moreover, as shown in FIG. 29C, by changing the direction of
movement, plasma processing of the plasma processing region 232 can
be achieved so that line connections in various directions (in
other words, continuous linear portions) are formed. Further, as
shown in FIG. 29D, by controlling the region where plasma
processing is carried out and the region where plasma processing is
not carried out by the plasma intermissive generation control unit
211, plasma processing of the plasma processing region 232 can be
achieved so that discontinuous regions or, in other words,
discontinuous linear portions are formed. Thus, according to the
eighth embodiment, there can be achieved plasma processing for
forming a pattern by processing a minute region at low cost without
using a mask pattern.
[0183] Moreover, in the eighth embodiment, an appropriate voltage
corresponding to a pressure and a gap between the electrodes is
needed to start plasma discharge, and this is known as the
Paschen's law. If the Paschen's law is applied to the eighth
embodiment, then the product PD of a pressure P of the discharge
space S and a thickness D of the discharge space S is provided. By
applying a voltage of not lower than a minimum ignition voltage Vs
corresponding to the product PD is applied across the opposed
electrodes 201 and 202 by the plasma intermissive generation
control unit 211, plasma discharge can be generated. If an
excessively high voltage is applied across the opposed electrodes
201 and 202, then a shift to arc discharge occurs, possibly causing
a concern about the damage of the electrode 201 or 202 or similar
concern. Accordingly, in the eighth embodiment, the voltage applied
across the opposed electrodes 201 and 202 has been set at 1 kV as
an example for the sake of safety by the plasma intermissive
generation control unit 211, and the ignition voltage has satisfied
the voltage of not higher than 1 kV within a range of about 0.1
(Pa.multidot.m) to 120 (Pa.multidot.m) as the product PD with
respect to air. Therefore, it is preferable to carry out the plasma
processing under the control of the plasma intermissive generation
control unit 211 on the condition that the product PD is 0.1
(Pa.multidot.m) to 120 (Pa.multidot.m)
[0184] Further, in the eighth embodiment, when the processing is
carried out with high-frequency power of a frequency lower than 1
MHz, the damage of the electrodes 201 and 202 is significant, the
processing cannot be achieved for a long time because the distance
between the electrodes 201 and 202 changes. Conversely, the plasma
discharge is not stable when the frequency exceeds 5 GHz, and
therefore, the appropriate frequency of the high-frequency power
supply 203 is 1 MHz to 5 GHz.
[0185] The ninth embodiment of the present invention will be
described next with reference to FIG. 30. It is to be noted that
the same components as those of the eighth embodiment are denoted
by same reference numerals with no description provided therefor,
and only the points of difference will be mainly described.
[0186] Referring to FIG. 30, first and second electrodes 201 and
202, a stage 209, a plasma generating section moving unit 210, and
a substrate holding stage 240 are arranged in a pressure-resistant
container 212, which is a pressure-resistant chamber capable of
maintaining the pressure at a reduced pressure or a high pressure.
The pressure-resistant container 212 is connected to a gas supply
unit 206 via a gas pipe 205, and the pressure-resistant container
212 is further connected to a vacuum pump 215 via a gas pipe 213
and a pressure control unit 214. Therefore, an arbitrary gas can be
flowed through the whole interior of the pressure-resistant
container 212 and, in particular, through the discharge space S
between the first and second electrodes 201 and 202. Moreover, the
interior can be controlled to an arbitrary pressure. Therefore, it
is possible to carry out the processing while changing the gas type
and pressure.
1 TABLE 1 Pressure (kPa) Etching Rate (nm/min) 1 300 10 1000 100
2000
[0187] Table 1 shows the pressure dependence of etching rate when
an interval between the electrodes 201 and 202 is set at 1 mm as
one example, oxygen is used as a gas supplied from the gas supply
unit 206, and an organic film is etched in the apparatus
construction of FIG. 30. There is observed an increase in etching
rate with an increase in pressure, and this makes it clear that the
etching rate can be controlled by pressure control.
[0188] Moreover, in the ninth embodiment, there is the possibility
of the occurrence of a comparatively intense electromagnetic waves
when the plasma processing-use pressure exceeds 200 kPa, or about
double the atmospheric pressure, and therefore, it is required to
carry out the processing at a pressure of not higher than 200 kPa
in the apparatus construction of the ninth embodiment. Moreover, in
the case of a pressure lower than 100 Pa, it is required to provide
an expensive turbo-molecular pump or the like as a vacuum pump 215,
and this consequently leads to high cost, meaning that it is not
appropriate. Therefore, it is desirable to carry out the plasma
processing at a pressure P of not lower than 100 Pa and not higher
than 200 kPa under the control of the plasma intermissive
generation control unit 211. Therefore, in the ninth embodiment, it
is preferable to execute control so that the pressure of the
discharge space is 100 Pa to 200 kPa and the product PD of the
pressure P of the discharge space and the thickness D of the
discharge space becomes 0.1 to 120 (Pa.multidot.m) under the
control of the plasma intermissive generation control unit 211.
[0189] Further, in connection with the aforementioned ninth
embodiment, there has been described only the case where oxygen is
used as a gas that is supplied from the gas supply unit 206 and
used for the plasma processing. However, the processing can easily
be achieved so long as the gas is a reactive gas or, in particular,
a gas including halogen element, oxygen, nitrogen or the like or a
rare gas that easily starts plasma discharge.
[0190] The tenth embodiment of the present invention will be
described next with reference to FIG. 31. It is to be noted that
the same components as those of the eighth embodiment are denoted
by same reference numerals with no description provided therefor,
and only the points of difference will be mainly described.
[0191] Referring to FIG. 31, a film 218 is disposed adjacently to
the opening 207 of the discharge space S located between the first
and second electrodes 201 and 202 in place of the substrate 208 as
an object to be processed, and this film 218 is subjected to a
variety of plasma processes of etching, film formation, surface
reforming, and the like. In concrete, a pre-processing film driving
roll 216 around which a pre-processing film 218 is wound and a
post-processing film driving roll 217 for taking up the
post-processing film 218 are provided, and the rolls are connected
to a plasma processing control unit 241 and subjected to operation
control.
[0192] The film 218 is drawn out and supplied from the
pre-processing film driving roll 216 around which the
pre-processing film 218 is wound, and the post-processing film 218
is taken up by the post-processing film driving roll 217 under the
control of the plasma processing control unit 241.
[0193] In each of the aforementioned eighth to tenth embodiments,
there have been described the ones constructed so that the plasma
generating section 245 for forming the discharge space S between
the first and second electrodes 201 and 202 is moved by the stage
209 and the plasma generating section moving unit 210 capable of
performing three-dimensional movement as examples. However, the
plasma generating section moving unit 210 may be merely required to
be a drive mechanism capable of executing three-dimensional
position control. Without being limited to the mechanism described
with reference to FIG. 28, there can be employed a system employing
a dial gauge, a drive mechanism employing a piezoelectric element,
and the like, appropriate for the accuracy of control and
applications. Moreover, it is only required to relatively change
the positions of the plasma generating section 245 and the object
to be processed, and therefore, it is needless to say that a
mechanism similar to the aforementioned one may be disposed on the
object side. For example, the substrate holding stage 240 may be a
substrate moving unit that is three-dimensionally controllable in
position, allowing the substrate 208 to be three-dimensionally
controllable in position. Otherwise, it is acceptable to make the
plasma generating section 245 drivable in the up-and-down direction
by the plasma generating section moving unit 210 and provide the
substrate holding stage 240 as a substrate moving unit that is
two-dimensionally controllable in position in the X- and Y-axes
that are laterally perpendicular to each other.
[0194] Combinations of the first through seventh embodiments and
the eighth through tenth embodiments of the present invention will
be described next. As one example of a combination of the first
embodiment and the eighth embodiment, a plasma processing apparatus
for putting a plasma processing method according to the eleventh
embodiment of the present invention into practice is first shown in
FIG. 34.
[0195] Referring to FIG. 34, a movement stage 300, which functions
as a plasma generating section moving unit, is arranged so as to be
able to advance and retreat along a rail 310 arranged parallel to a
substrate 11. As one example, the rail 310 and the movement stage
300 have a structure as shown in FIG. 28. That is, a stage 221
corresponding to the movement stage 300 is movably supported on a
rail guide 222 that has bearings inside the rail 310 and meshed
with a ball thread 222a arranged along the rail guide 222. By
forwardly and reversely rotatively driving the ball thread 222a by
a drive unit 223 that has a reversibly rotatable servomotor 223A
and a reduction gear 223B, the stage 221 and also the movement
stage 300 are made advance and retreat along the rail 310.
[0196] A plasma processing control unit 341 is connected to the
servomotor 223A, a high-frequency power supply 12, a gas supply
unit 7, and a memory 342 that stores various sorts of plasma
processing information of the substrate 11 (if a substrate holding
stage similar to the substrate holding stage 240 is arranged at
need, the unit is also connected to the substrate holding stage).
On the basis of the various sorts of plasma processing information
stored in the memory 342, application control of high-frequency
power from the high-frequency power supply 12 to the electrode 13,
and gas supply control by the gas supply unit 7, and position
control of the microplasma generating-use space 3 by the plasma
generating section movement stage 300 (and further substrate
position control by the substrate holding stage at need) are
executed respectively. According to this operation, by moving the
microplasma generating-use space 3 while carrying out plasma
processing, the plasma processing can be carried out automatically
at an arbitrary plasma density throughout the desired region.
[0197] As another example, FIG. 35 shows a plasma processing
apparatus for putting a plasma processing method according to the
twelfth embodiment of the present invention into practice.
[0198] Referring to FIG. 35, by supporting the microplasma source
of FIG. 1 on the stage 209 instead of the plasma generating section
245 of the plasma processing apparatus of FIG. 27, the microplasma
source of FIG. 1 is able to advance and retreat independently in
the directions of X, Y, and Z axes by the driving of the plasma
generating section moving unit 210.
[0199] Moreover, it is acceptable to apply the plasma processing
conditions of the eighth through tenth embodiments to the first
through seventh embodiments of the present invention. That is, for
example, by providing the plasma processing apparatus of the first
embodiment further with a plasma processing control unit 341 as
shown in FIG. 34 or with a plasma processing control unit 241 as
shown in FIG. 35, there is executable control so that the pressure
of the space 3 of the microplasma source becomes 100 Pa to 200 kPa
and the product PD of the pressure P of the space 3 of the
microplasma source and the thickness D of the space 3 of the
microplasma source becomes 0.1 to 120 (Pa.multidot.m). Furthermore,
as described hereinabove, the space 3 of the microplasma source and
the substrate 11 can be moved relatively to each other by the
plasma generating section moving unit 210 or 300.
[0200] Therefore, when the fine linear portion 15 is formed on the
substrate 11, there is executed control so that the pressure of the
space 3 of the microplasma source is maintained at 100 Pa to 200
kPa and the product PD of the pressure P of the space 3 of the
microplasma source and the thickness D of the space 3 of the
microplasma source becomes 0.1 to 120 (Pa.multidot.m). By supplying
electric power to the member located in the vicinity of the space 3
of the microplasma source or, for example, the electrode 25, plasma
is generated in the space 3 of the microplasma source.
Subsequently, the fine linear portion 15 may be formed on the
substrate 11 by the plasma generated as above by moving the
generated plasma and the substrate 11 relatively to each other.
[0201] As described above, according to the combinations of the
first through seventh embodiments and the eighth through tenth
embodiments of the present invention, the effects provided by the
embodiments combined in various ways can be collectively produced,
and the pattern forming-use plasma processing can be put into
practice by processing the minute region at lower cost more
efficiently and more accurately also without using a mask
pattern.
[0202] According to the plasma processing apparatus and method of
the present invention, by arranging the first and second electrodes
opposite to each other to form the discharge space between both the
electrodes, supplying the gas to the discharge space, executing
control so that the pressure of the discharge space is maintained
at 100 Pa to 200 kPa and the product PD of the pressure P of the
discharge space and the thickness D of the discharge space becomes
0.1 to 120 (Pa.multidot.m), applying the high-frequency power to
the first electrode to generate plasma in the discharge space,
moving the generated plasma and the object to be processed
relatively to each other, and processing the object to be processed
with the generated plasma, an arbitrary pattern can be processed
without using a mask pattern by moving the plasma generating
section and the object to be processed relatively to each other
while processing the minute region facing the discharge space with
the plasma generated by supplying the gas to the discharge space
located between the electrodes. Moreover, by limiting the pressure
of the discharge space and the relation between the pressure and
the thickness of the discharge space as described-hereinabove,
plasma processing can be carried out at low cost without using an
expensive evacuation means nor generating intense electromagnetic
waves. Moreover, plasma processing can be started by discharge
ignition without making the application voltage extremely high.
[0203] Moreover, it is suitable for the processing of the minute
gap to supply the gas from one end of the discharge space and
process the object to be processed disposed oppositely to the
opening at the other end of the discharge space.
[0204] Moreover, if the processing is carried out with the plasma
generated intermittently, then a discontinuous pattern can be
arbitrarily formed.
[0205] Moreover, it is suitable for processing a film-shaped object
to be processed to provide the moving unit of the object to be
processed by a roll for winding up the film-shaped object to be
processed.
[0206] Moreover, the gas can be provided by a reactive gas having
reactivity according to processing or, in particular, gas including
at least one of halogen element, oxygen, and nitrogen, and the
plasma discharge can easily be started when a rare gas is used.
[0207] Moreover, it is preferable to use high-frequency power
having a frequency of 1 MHz to 5 GHz in enabling the restraint of
the wearing of the electrodes and the stabilization of plasma
discharge.
[0208] By properly combining arbitrary embodiments out of the
aforementioned various embodiments, the effects owned by them can
be produced.
[0209] Although the present invention has been fully described in
connection with the preferred embodiments thereof with reference to
the accompanying drawings, it is to be noted that various changes
and modifications are apparent to those skilled in the art. Such
changes and modifications are to be understood as included within
the scope of the present invention as defined by the appended
claims unless they depart therefrom.
* * * * *