U.S. patent application number 11/905976 was filed with the patent office on 2008-02-28 for processing method, manufacturing method of semiconductor device, and processing apparatus.
This patent application is currently assigned to Kabushiki Kaisha Toshiba. Invention is credited to Hiroshi Ikegami, Shinichi Ito, Kenji Kawano, Riichiro Takahashi, Tomoyuki Takeishi.
Application Number | 20080050677 11/905976 |
Document ID | / |
Family ID | 29714277 |
Filed Date | 2008-02-28 |
United States Patent
Application |
20080050677 |
Kind Code |
A1 |
Takeishi; Tomoyuki ; et
al. |
February 28, 2008 |
Processing method, manufacturing method of semiconductor device,
and processing apparatus
Abstract
A processing method for selectively reducing or removing the
region to be exposed with energy ray in a film formed on a
substrate, comprising relatively scanning a first exposure light
whose shape on the substrate is smaller than the whole first region
to be exposed against the whole first region to be exposed to
selectively remove or reduce the first region to be exposed, and
exposing a whole second region to be exposed inside the whole first
region to be exposed with a second exposure light to selectively
expose the whole second region to be exposed.
Inventors: |
Takeishi; Tomoyuki;
(Yokohama-shi, JP) ; Kawano; Kenji; (Yokohama-shi,
JP) ; Ikegami; Hiroshi; (Hiratsuka-shi, JP) ;
Ito; Shinichi; (Yokohama-shi, JP) ; Takahashi;
Riichiro; (Yokohama-shi, JP) |
Correspondence
Address: |
FINNEGAN, HENDERSON, FARABOW, GARRETT & DUNNER;LLP
901 NEW YORK AVENUE, NW
WASHINGTON
DC
20001-4413
US
|
Assignee: |
Kabushiki Kaisha Toshiba
|
Family ID: |
29714277 |
Appl. No.: |
11/905976 |
Filed: |
October 5, 2007 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10436972 |
May 14, 2003 |
7288466 |
|
|
11905976 |
Oct 5, 2007 |
|
|
|
Current U.S.
Class: |
430/311 |
Current CPC
Class: |
B23K 26/066 20151001;
B23K 26/364 20151001; H01L 2924/0002 20130101; G21K 5/10 20130101;
H01L 23/544 20130101; H01L 2223/54453 20130101; G03F 9/7076
20130101; G03F 7/2026 20130101; H01J 2237/30438 20130101; H01L
2924/0002 20130101; B23K 2103/172 20180801; G03F 7/70341 20130101;
B23K 26/40 20130101; Y10S 438/949 20130101; G03F 9/7084 20130101;
H01L 2924/00 20130101; G03F 9/708 20130101 |
Class at
Publication: |
430/311 |
International
Class: |
G03C 5/00 20060101
G03C005/00 |
Foreign Application Data
Date |
Code |
Application Number |
May 14, 2002 |
JP |
2002-139083 |
Sep 20, 2002 |
JP |
2002-275894 |
Claims
1-22. (canceled)
23. A manufacturing method of a semiconductor device, comprising:
preparing a substrate material in which an alignment mark is formed
in or on a semiconductor substrate; forming an anti-reflection film
and subsequently forming resist film on the anti-reflection film;
relatively scanning a first exposure light against the whole first
region to be exposed on the substrate to selectively remove or
reduce the anti-reflection film of the whole first region to be
exposed including a region above which the alignment mark is
formed; exposing irradiating a whole second region to be exposed
inside the whole first region to be exposed with a second exposure
light to selectively remove or reduce the whole second region to be
exposed of the anti-reflection film; processing the anti-reflection
film and subsequently transferring the substrate material to an
exposure apparatus for forming a latent image; performing alignment
adjustment by the alignment mark in the exposure apparatus; forming
a latent image of a semiconductor circuit on the resist film after
the alignment adjustment; developing the resist film in which the
latent image is formed to form a resist pattern; and using the
resist pattern to process the substrate material.
24. A processing method for exposing each exposing unit region with
an energy ray to selectively remove or reduce a whole region to be
exposed of the film formed on a substrate, comprising: exposing the
exposing unit region of the substrate with the energy ray;
observing a gas member generated by exposure of the energy ray
above exposing unit region; measuring a size of the gas member; and
exposing the film with the next energy ray, when the size of the
gas member is smaller than a defined value.
25. The processing method according to claim 24, further
comprising: relatively scanning the energy ray whose exposure
region is smaller than the whole region to be exposed against the
whole region to be exposed.
26. The processing method according to claim 24, wherein a shape of
the exposure region of the energy ray on the substrate is a slit or
dot shape.
27. The processing method according to claim 24, further
comprising: exposing the energy ray in a state in which a solution
or gas is passed onto the exposure region of the energy ray on the
substrate.
28. (canceled)
29. The processing method according to claim 24, wherein the film
to be exposed comprises an anti-reflection film, resist film,
polyimide, silicon nitride film, silicon carbide film, metal film,
or resin insulating film.
30. The processing method according to claim 24, wherein the
substrate has an alignment mark or a bar in bar mark formed below
the whole region to be exposed of the film.
31. The processing method according to claim 24, wherein a contour
length of the exposure region of the energy ray on the substrate is
180 .mu.m or less.
32. (canceled)
33. The processing method according to claim 31, further
comprising: relatively scanning the energy ray whose exposure
region is smaller than the whole region to be exposed against the
whole region to be exposed.
34. The processing method according to claim 31, wherein a shape of
the exposure region of the energy ray on the substrate is a slit or
dot shape.
35. The processing method according to claim 31, further
comprising: exposing the energy ray in a state in which a solution
or gas is passed onto the exposure region of the energy ray on the
substrate.
36. (canceled)
37. The processing method according to claim 31, wherein the film
to be exposed comprises an anti-reflection film, resist film,
polyimide, silicon nitride film, silicon carbide film, metal film,
or resin insulating film.
38. The processing method according to claim 31, wherein the
substrate has an alignment mark or a bar in bar mark formed below
the whole region to be exposed of the film.
39.-81. (canceled)
82. A processing method comprising: forming a first film on a
substrate; forming a second film on the first film; selectively
exposing the films on the substrate with a first energy ray; and
maintaining at least a part of the second film of the whole region
to be exposed with the first energy ray, while exposing the first
film, wherein the processing of the first film comprises:
vaporizing the first film; or changing a transmittance.
83. The processing method according to claim 82, wherein the first
film is an anti-reflection film.
84. The processing method according to claim 82, wherein the second
film is a resist film.
85. The processing method according to claim 82, further
comprising: forming the second film as an intermediate film; and
forming a resist film on the intermediate film.
86. The processing method according to claim 85, wherein the
forming of the resist film is performed after exposing the first
film with the first energy.
87. The processing method according to claim 85, wherein the
intermediate film is a silicon oxide film.
88. The processing method according to claim 82, further
comprising: preparing the substrate having an alignment mark;
processing the first film above the alignment mark with the first
energy ray; exposing the alignment mark with a second energy ray to
acquire position information of the alignment mark from reflected
the second energy ray; and exposing the resist film with a third
energy ray based on the position information to form a desired
latent image pattern on the resist film.
89. The processing method according to claim 88, wherein a
wavelength of the second energy ray is the same as that of the
third energy ray.
90. (canceled)
91. The processing method according to claim 88, wherein the first
energy ray is a light having a wavelength absorbed by the first
film.
92. The processing method according to claim 82, wherein the
processing of the first film comprises: relatively scanning the
first energy ray having a first shape against the first region to
be exposed on the substrate; and exposing a second region to be
exposed inside the first region to be exposed with the first
energy.
93. A manufacturing method of a semiconductor device, comprising:
preparing a substrate material in which an alignment mark is formed
in or on a semiconductor substrate; forming an anti-reflection film
on the substrate material; forming a resist film on the
anti-reflection film; selectively exposing the resist film of a
whole region to be exposed including a region above which the
alignment mark is formed with an energy ray; maintaining at least a
part of the resist film of the whole region to be exposed with the
first energy ray, while exposing the anti-reflection film,
transferring the substrate material to an exposure apparatus after
processing the anti-reflection film; using the alignment mark to
perform alignment adjustment; forming a latent image of a
semiconductor circuit on the resist film after the alignment
adjustment; and developing the resist film to form a resist
pattern, wherein the processing of the anti-reflection film
comprises: vaporizing the anti-reflection film; or changing a
transmittance.
94. A manufacturing method of a semiconductor device, comprising:
preparing a substrate material in which an alignment mark is formed
in or on a semiconductor substrate; forming an anti-reflection film
and intermediate film on the substrate material; selectively
exposing the intermediate film of a whole region to be exposed
including a region above which the alignment mark is formed with an
energy ray; maintaining at least a part of the intermediate film of
the whole region to be exposed with the first energy ray, while
exposing the anti-reflection film; forming a resist film on the
intermediate film after processing the anti-reflection film;
transferring the substrate material in which the resist film is
formed to an exposure apparatus; using the alignment mark in the
exposure apparatus to perform alignment adjustment; forming a
latent image of a semiconductor circuit on the resist film after
the alignment adjustment; developing the resist film in which the
latent image is formed to form a resist pattern; and using the
resist pattern to process the substrate material, wherein the
exposing of the anti-reflection film comprises: vaporizing the
anti-reflection film; or changing a transmittance.
95.-108. (canceled)
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is based upon and claims the benefit of
priority from the prior Japanese Patent Applications No.
2.002-139083, filed May 14, 2002; and No. 2002-275894, filed Sep.
20, 2002, the entire contents of both of which are incorporated
herein by reference.
BACKGROUND OF THE INVENTION
[0002] 1. Field of the Invention
[0003] The present invention relates to a processing method for
selectively processing a film to be exposed formed on a substrate,
manufacturing method of a semiconductor device, and processing
apparatus.
[0004] 2. Description of the Related Art
[0005] In general, with advance of semiconductor element
miniaturization, it has become essential to enhance precision of an
alignment technique with a lower layer in a lithography process. To
align a pattern already formed on a substrate with a pattern to be
exposed at exposing latent image, an exclusive scope for detecting
an alignment mark position has heretofore been used. However, since
an offset surely exists between the exclusive scope for alignment
and exposure axis in this method, a deviation is generated between
the alignment scope and exposure axis because of an influence of
thermal drift, and an alignment deviation of the alignment mark
position is generated. Therefore, with the advance of the
miniaturization of a semiconductor, a problem has occurred that
magnitude of the alignment deviation of the alignment position
largely influences yield of a chip.
[0006] To improve this, an exposure-through-the-reticle (ETTR)
method of detecting alignment mark and exposing pattern along the
same axis is considered as a promising alignment technique of the
next generation. In the ETTR method, high-precision alignment can
be realized. On the other hand, since light source with same
wavelength of a DUV region as that of the exposure is used, light
absorption is large in an anti-reflection film formed below a
resist layer. A problem occurs that position information cannot be
detected from the alignment mark in the anti-reflection film lower
layer. Similarly, when the films formed on the alignment mark such
as an organic insulating film and interlayer insulating film of SiN
or SiC is opaque to an exposure light, position information of the
alignment mark cannot be detected. Moreover, even when the
alignment by ETTR is not performed, and even when contrast of an
alignment light is weak, position information of alignment cannot
be detected.
[0007] To solve the problem, there has been proposed a method of
selectively remove the opaque film formed on the alignment mark
with laser ablation before an alignment step. However, this method
has a problem that particles generated at a laser ablation sticks
to a device pattern region, which forms a critical defect.
BRIEF SUMMARY OF THE INVENTION
[0008] (1) According to one aspect of the present invention, there
is provided a processing method for selectively removing or
reducing a region to be processed of a film formed on a substrate,
comprising: relatively scanning a first exposing light whose
exposure region on the substrate is smaller than the whole first
region to be exposed against the substrate to selectively process
the whole first region to be processed of the film; and exposing a
second region to be exposed inside the first region to be exposed
with a second exposing light to selectively process the whole
second region to be exposed.
[0009] (2) According to one aspect of the present invention, there
is provided a manufacturing method of a semiconductor device,
comprising:
[0010] preparing a substrate material in which an alignment mark is
formed in or on a semiconductor substrate;
[0011] forming an anti-reflection film and resist film on the
substrate material;
[0012] relatively scanning a first exposing light against the whole
first region to be exposed on the substrate to selectively remove
or reduce the anti-reflection film of a first region to be exposed
including a region above which the alignment mark is formed;
[0013] exposing a second region to be exposed inside the whole
first region to be exposed with a second exposing light to
selectively remove or reduce the whole second region to be exposed
of the anti-reflection film;
[0014] processing the anti-reflection film and subsequently
transferring the substrate material to an exposure apparatus;
[0015] using the alignment mark in the exposure apparatus to
perform alignment adjustment;
[0016] forming a latent image of a semiconductor circuit on the
resist film after the alignment adjustment;
[0017] developing the resist film in which the latent image is
formed to form a resist pattern; and
[0018] using the resist pattern to process the substrate
material.
[0019] (3) According to one aspect of the present invention, there
is provided a processing method for exposing each processing unit
with an energy ray to selectively remove or reduce a whole region
to be exposed of a film formed on a substrate, comprising:
[0020] exposing the processing unit of the substrate with the
energy ray;
[0021] observing a gas member generated by exposure of the energy
ray in an optical path of the energy ray;
[0022] measuring a size of the gas member; and
[0023] exposing the film to be exposed with the next energy ray,
when the size of the gas member is smaller than a defined
value.
[0024] (4) According to one aspect of the present invention, there
is provided a processing method for exposing a whole region to be
exposed of a substrate with an energy ray to selectively remove or
reduce the whole region to be exposed, comprising:
[0025] passing a solution through the whole region to be exposed at
a flow velocity V (.mu.m/sec);
[0026] exposing whole the region to be exposed through which the
solution flows with the energy ray having an oscillation frequency
Z (1/sec) and a width W (.mu.m) of a direction in which the
solution flows; and
[0027] controlling the flow velocity V, width W, and oscillation
frequency Z so as to satisfy the following relation: V .gtoreq. 6
.times. W 2 .times. Z . ##EQU1##
[0028] (5) According to one aspect of the present invention, there
is provided a processing method for selectively removing or
reducing a whole region to be exposed of an organic film formed on
a substrate, comprising:
[0029] exposing the whole region to be exposed with an energy ray
whose the exposure region on the substrate is smaller than the
whole region to be exposed on conditions of an oscillation
frequency f (1/sec) and energy density per pulse, on which the
organic film can be removed; and
[0030] relatively scanning an exposure region of the energy ray
against the whole region to be exposed on the substrate at a speed
v (.mu.m/sec),
[0031] wherein the oscillation frequency f and speed v satisfy the
following relation: 6.0 .times. 10 - 5 .ltoreq. v f 2 .ltoreq. 1.0
.times. 10 - 3 . ##EQU2##
[0032] (6) According to one aspect of the present invention, there
is provided a processing apparatus for selectively removing or
reducing a whole region to be exposed of a film formed on a
substrate, comprising:
[0033] a substrate hold portion which holds the substrate;
[0034] a ray source which generates an energy ray to selectively
reduce or remove a part of the film to be exposed;
[0035] a shaping portion which is disposed on an optical axis of
the energy ray and which shapes the energy ray generated by the ray
source;
[0036] a scan portion which relatively scans the energy ray shaped
by the shaping against the whole region to be exposed on the
substrate; and
[0037] a solution supply portion which changes a flow direction of
a solution in accordance with a scan direction of the energy ray by
the scan portion to continuously supply the solution to the surface
of the whole region to be exposed on the substrate.
[0038] (7) According to one aspect of the present invention, there
is provided a processing apparatus for selectively reducing or
removing a whole region to be exposed of a film formed on a
substrate, comprising:
[0039] a substrate hold portion which holds, the substrate;
[0040] a ray source which generates an energy ray to selectively
reduce or remove a part of the film to be processed;
[0041] a shaping portion which is disposed on an optical axis of
the energy ray and which shapes the energy ray generated by the ray
source and which emits energy rays having a irradiation shape on
the substrate arranged by designed period; and
[0042] a scan portion which relatively scans the energy rays
against the whole region to be exposed on the substrate in the
designed period or less.
[0043] (8) According to one aspect of the present invention, there
is provided a processing apparatus comprising:
[0044] a hold portion which holds a substrate;
[0045] an irradiation portion which generates an energy ray to
reduce or remove a part of a film to be exposed of the
substrate;
[0046] an observation/measurement portion which observes a gas
member generated by abrasion of the film to be exposed by exposure
of the energy ray on an optical path of the energy ray; and
[0047] a control portion which controls an exposure timing of the
energy ray emitted from the exposure portion in accordance with an
observation/measurement result of the observation/measurement
portion.
[0048] (9) According to one aspect of the present invention, there
is provided a processing apparatus for selectively reducing or
removing a whole region to be exposed of a film formed on a
substrate, comprising:
[0049] a hold portion which holds the substrate;
[0050] an exposure portion which exposures each processing unit set
in the region to be exposed with an energy ray having an
oscillation frequency Z (1/sec) and width W (.mu.m) of one
direction of an exposure region in the film to be exposed;
[0051] a supply portion which supplies a solution onto the region
to be exposed of the film in one direction at a flow velocity V;
and
[0052] a control portion which controls any one of the oscillation
frequency Z, width W, and flow velocity V so as to satisfy the
following relation: V .gtoreq. 6 .times. W 2 .times. Z .
##EQU3##
[0053] (10) According to one aspect of the present invention, there
is provided a processing apparatus for selectively processing a
whole region to be exposed of an organic film formed on a
substrate, comprising:
[0054] a hold portion which holds the substrate;
[0055] an exposure portion which exposures the substrate with an
energy ray whose exposure region on the substrate is smaller than
the whole region to be exposed at an oscillation frequency f
(1/sec) and energy density per pulse so that the organic film can
be removed;
[0056] a scan portion which relatively scans an exposure region of
the energy ray against the whole region to be exposed on the
substrate at a speed v (.mu.n/sec); and
[0057] a control portion to control at least one of the irradiation
portion and scan portion so that the oscillation frequency f and
speed v satisfy the following relation: 6.0 .times. 10 - 5 .ltoreq.
v f 2 .ltoreq. 1.0 .times. 10 - 3 . ##EQU4##
[0058] (11) According to one aspect of the present invention, there
is provided a processing method comprising:
[0059] forming a first film on a substrate;
[0060] forming a second film on the first film;
[0061] selectively exposing the substrate with a first energy ray;
and
[0062] maintaining at least a part of an irradiation of the first
energy ray of the second film while reducing or removing the first
film,
[0063] wherein the reducing or removing of the first film
comprises: vaporizing the first film; or changing a
transmittance.
[0064] (12) According to one aspect of the present invention, there
is provided a manufacturing method of a semiconductor device,
comprising:
[0065] preparing a substrate material in which an alignment mark is
formed in or on a semiconductor substrate;
[0066] forming an anti-reflection film on the substrate
material;
[0067] forming a resist film on the anti-reflection film;
[0068] selectively exposing the resist film of a region to be
exposed including a region above which the alignment mark is formed
with an energy ray;
[0069] maintaining at least a part of the resist film of the region
to be exposed while reducing or removing the anti-reflection
film;
[0070] transferring the substrate material to an exposure apparatus
after processing the anti-reflection film;
[0071] using the alignment mark to perform alignment
adjustment;
[0072] forming a latent image of a semiconductor circuit on the
resist film after the alignment adjustment; and
[0073] developing the resist film to form a resist pattern,
[0074] wherein the processing of the anti-reflection film
comprises: vaporizing the anti-reflection film; or changing a
transmittance.
[0075] (13) According to one aspect of the present invention, there
is provided a manufacturing method of a semiconductor device,
comprising:
[0076] preparing a substrate material in which an alignment mark is
formed in or on a semiconductor substrate;
[0077] forming an anti-reflection film and intermediate film on the
substrate material;
[0078] selectively exposing the intermediate film of a whole region
to be exposed including a region above which the alignment mark is
formed with an energy ray;
[0079] maintaining at least a part of the intermediate film of the
whole region to be exposed while reducing or removing the
anti-reflection film;
[0080] forming a resist film on the intermediate film after
reducing or removing the anti-reflection film;
[0081] transferring the substrate material in which the resist film
is formed to an exposure apparatus;
[0082] using the alignment mark in the exposure apparatus to
perform alignment adjustment;
[0083] forming a latent image of a semiconductor circuit on the
resist film after the alignment adjustment; and
[0084] developing the resist film in which the latent image is
formed to form a resist pattern; and
[0085] using the resist pattern to process the substrate
material,
[0086] wherein the processing of the anti-reflection film
comprises: vaporizing the anti-reflection film; or changing a
transmittance.
[0087] (14) According to one aspect of the present invention, there
is provided a processing method for exposing each processing unit
with an energy ray to selectively reduce or remove a whole region
to be exposed of a film formed on a substrate, comprising:
[0088] obtaining an intensity distribution of a reflected light
from the substrate;
[0089] determining an energy amount of the energy ray with which
each processing unit is irradiated from the intensity distribution
of the reflected light; and
[0090] successively exposing the respective processing units with
the energy ray based on the determined energy amount.
[0091] (15) According to one aspect of the present invention, there
is provided a processing method for exposing each processing unit
with an energy ray to selectively remove or reduce a whole region
to be exposed of a film formed on a substrate, comprising:
[0092] obtaining an intensity distribution of a reflected light
from the substrate;
[0093] classifying the intensity distribution of the reflected
light for each region having an equal reflected light
intensity;
[0094] setting the processing unit in accordance with the
classified region;
[0095] determining an energy amount of the energy ray with which
each processing unit is exposed in accordance with the reflected
light intensity; and
[0096] successively exposing each processing unit with the energy
ray based on the determined energy amount.
[0097] (16) According to one aspect of the present invention, there
is provided a processing apparatus for selectively removing or
reducing a whole region to be exposed of a film formed on a
substrate, comprising:
[0098] a hold portion which holds the substrate;
[0099] an exposure portion which exposure each processing unit set
in the region to be exposed with an energy ray;
[0100] a detection portion which exposes each processing unit with
an observation light to detect a reflected light intensity from the
processing unit;
[0101] a setting portion to set an energy amount of the energy ray
with which each processing unit is exposed in accordance with the
detected reflected light intensity; and
[0102] a control portion to control the energy amount of the energy
ray with which each processing unit is exposed from the exposure
portion in accordance with the energy amount set by the setting
portion.
BRIEF DESCRIPTION OF THE SEVERAL VIEWS OF THE DRAWING
[0103] FIGS. 1A to 1G are sectional views showing manufacturing
steps of a semiconductor device according to a first
embodiment;
[0104] FIG. 2 is a diagram showing a constitution of an optical
processing apparatus according to the first embodiment;
[0105] FIG. 3 is a diagram showing a schematic constitution of an
optical shaping portion;
[0106] FIG. 4 is a diagram showing a constitution of a view field
setting system according to the first embodiment;
[0107] FIGS. 5A and 5B are diagrams showing an operation example of
the view field setting system;
[0108] FIG. 6 is a diagram showing the constitution of the view
field setting system according to the first embodiment;
[0109] FIG. 7 is a diagram showing a constitution of a slit/dot
setting system according to the first embodiment;
[0110] FIG. 8 is a diagram showing the constitution of the slit/dot
setting system according to the first embodiment;
[0111] FIGS. 9A to 9D are plan views showing an example of a
diaphragm of the slit/dot setting system according to the first
embodiment;
[0112] FIG. 10 is a plan view showing the example of the diaphragm
of the slit/dot setting system according to the first
embodiment;
[0113] FIG. 11 is a plan view showing a manufacturing step of the
semiconductor device according to the first embodiment;
[0114] FIG. 12 is a diagram showing a surface state of a substrate
from which a film has been removed in a method according to the
first embodiment;
[0115] FIG. 13 is a diagram showing the surface state of the
substrate from which the film has been removed in a related-art
method;
[0116] FIGS. 14A and 14B are sectional views showing the
manufacturing steps of the semiconductor device according to the
first embodiment;
[0117] FIGS. 15A and 15B are diagrams showing the manufacturing
steps of the semiconductor device according to a second
embodiment;
[0118] FIGS. 16A and 16B are diagrams showing the manufacturing
steps of the semiconductor device according to the second
embodiment;
[0119] FIGS. 17A and 17B are diagrams showing the manufacturing
steps of the semiconductor device according to a third
embodiment;
[0120] FIGS. 18A and 18B are diagrams showing the manufacturing
steps of the semiconductor device according to the third
embodiment;
[0121] FIGS. 19A and 19B are diagrams showing the manufacturing
steps of the semiconductor device according to a fourth
embodiment;
[0122] FIGS. 20A and 20B are diagrams showing the manufacturing
steps of the semiconductor device according to the fourth
embodiment;
[0123] FIG. 21 is a diagram showing the manufacturing step of the
semiconductor device according to a fifth embodiment;
[0124] FIG. 22 is a diagram showing the manufacturing step of the
semiconductor device according to the fifth embodiment;
[0125] FIGS. 23A and 23B are sectional views showing the
manufacturing steps of the semiconductor device according to a
sixth embodiment;
[0126] FIGS. 24A to 24C are sectional views showing the
manufacturing steps of the semiconductor device according to a
seventh embodiment;
[0127] FIGS. 25A to 25C are plan views showing diaphragms mounted
in an S/D diaphragm system according to an eighth embodiment;
[0128] FIGS. 26A and 26B are sectional views showing the
manufacturing steps of the semiconductor device according to the
eighth embodiment;
[0129] FIGS. 27A and 27B are sectional views showing the
manufacturing steps of the semiconductor device according to a
ninth embodiment;
[0130] FIG. 28 is a sectional view showing the manufacturing step
of the semiconductor device according to the ninth embodiment;
[0131] FIGS. 29A and 29B are sectional views showing the
manufacturing steps of the semiconductor device according to a
tenth embodiment;
[0132] FIGS. 30A and 30B are sectional views showing the
manufacturing steps of the semiconductor device according to an
eleventh embodiment;
[0133] FIG. 31 is a sectional view showing the manufacturing step
of the semiconductor device according to a twelfth embodiment;
[0134] FIGS. 32A to 32C are sectional views showing the
manufacturing steps of the semiconductor device according to the
twelfth embodiment;
[0135] FIGS. 33A to 33C are sectional views showing the
manufacturing steps of the semiconductor device according to a 13th
embodiment;
[0136] FIGS. 34A to 34F are sectional views showing the
manufacturing steps of the semiconductor device according to a 14th
embodiment; FIGS. 35A to 35D are sectional views showing the
manufacturing steps of the semiconductor device according to a 15th
embodiment;
[0137] FIGS. 36A to 36C are sectional views showing the
manufacturing steps of the semiconductor device according to a 16th
embodiment;
[0138] FIG. 37 is a diagram showing a schematic constitution of a
processing unit according to an 18th embodiment;
[0139] FIGS. 38A and 38B are plan views showing a processing state
using the processing unit shown in FIG. 37;
[0140] FIGS. 39A and 39B are diagrams showing a constitution of a
liquid supply unit;
[0141] FIGS. 40A to 40C are sectional views showing a problem of an
alignment defect in forming a metal wiring of Al;
[0142] FIGS. 41A to 41F are sectional views showing the
manufacturing steps of the semiconductor device according to a 19th
embodiment;
[0143] FIGS. 42A to 42E are plan views showing an optical
processing method according to a 20th embodiment;
[0144] FIGS. 43A and 43B are sectional views showing the
manufacturing steps of the semiconductor device according to a 21st
embodiment;
[0145] FIG. 44 is a plan view showing an irradiation region of one
pulse of a laser beam;
[0146] FIGS. 45A and 45B are sectional views showing the
manufacturing steps of the semiconductor device according to a 22nd
embodiment;
[0147] FIG. 46 is a plan view showing an irradiation area of one
pulse of the laser beam;
[0148] FIG. 47 is a diagram showing a constitution of a laser
processing apparatus according to a 23rd embodiment;
[0149] FIG. 48 is a diagram showing the constitution of the laser
processing apparatus according to the 23rd embodiment;
[0150] FIG. 49 is a diagram showing an example of an image obtained
from a CCD camera of a laser processing apparatus;
[0151] FIGS. 50A to 50C are sectional views showing an example of a
film structure according to the 23rd embodiment;
[0152] FIG. 51 is a diagram showing setting of an energy amount in
each irradiation region in the processing method according to the
23rd embodiment;
[0153] FIG. 52 is a diagram showing the setting of the energy
amount in each irradiation region in the processing method
according to the 23rd embodiment;
[0154] FIG. 53 is a sectional view showing the constitution of the
semiconductor device formed in the processing method according to
the 23rd embodiment;
[0155] FIG. 54 is a diagram showing the setting of the energy
amount in each irradiation region in a related-art processing
method;
[0156] FIG. 55 is a sectional view showing the constitution of the
semiconductor device formed in the related-art processing
method;
[0157] FIG. 56 is a diagram showing an example of the image
obtained from the CCD camera of the laser processing apparatus
according to a 25th embodiment;
[0158] FIGS. 57A to 57C are sectional views showing an example of
the film structure according to the 25th embodiment;
[0159] FIG. 58 is a diagram showing the setting of the energy
amount in each irradiation region in the processing method
according to the 25th embodiment;
[0160] FIG. 59 is a diagram showing the constitution of the laser
processing apparatus according to a 26th embodiment;
[0161] FIG. 60 is a diagram showing the constitution of the laser
processing apparatus according to the 26th embodiment;
[0162] FIGS. 61A to 61C are diagrams showing the optical processing
method in which bubbles are not considered;
[0163] FIGS. 62A and 62B are diagrams showing the optical
processing method according to a 27th embodiment;
[0164] FIG. 63 is a diagram showing a relation between a distance
from a processed region and the number of pinholes in a case in
which the processing is performed in consideration of the
bubbles;
[0165] FIGS. 64A and 64B are diagrams showing an irradiation region
shape of the laser beam in the optical processing according to the
27th embodiment;
[0166] FIGS. 65A and 65B are diagrams showing the irradiation
region shape of the laser beam in collective processing;
[0167] FIGS. 66A and 66B are diagrams showing the irradiation
region shape of the laser beam in the optical processing according
to the 27th embodiment;
[0168] FIG. 67 is a diagram showing a relation between a diameter
of the bubble and the number of pinholes;
[0169] FIG. 68 is a diagram showing a relation between a width W of
the irradiation region and a bubble, diameter .phi. generated at a
processing time;
[0170] FIGS. 69A and 69B are sectional views showing the optical
processing performed while an air current is generated in the
processed region in the atmosphere;
[0171] FIGS. 70A and 70B are diagrams showing the manufacturing
steps of the semiconductor device according to a 28th
embodiment;
[0172] FIGS. 71A and 71B are diagrams showing the manufacturing
steps of the semiconductor device according to a 29th
embodiment;
[0173] FIGS. 72A and 72B are diagrams showing the manufacturing
steps of the semiconductor device according to a 30th
embodiment;
[0174] FIGS. 73A and 73B are diagrams showing the manufacturing
steps of the semiconductor device according to a 31st
embodiment;
[0175] FIGS. 74A to 74D are diagrams showing the manufacturing
steps of the semiconductor device according to a 32nd
embodiment;
[0176] FIGS. 75A and 75B are diagrams showing the manufacturing
steps of the semiconductor device according to a 33rd
embodiment;
[0177] FIGS. 76A to 76F are sectional views showing the
manufacturing steps of the semiconductor device according to a 34th
embodiment;
[0178] FIGS. 77A to 77H are sectional view showing the
manufacturing steps of the semiconductor device according to a 35th
embodiment;
[0179] FIG. 78 is a sectional view showing the semiconductor device
of a chip-on-chip type according to a 36th embodiment;
[0180] FIGS. 79A to 79H are sectional views showing the
manufacturing steps of the semiconductor device according to the
36th embodiment;
[0181] FIGS. 80A and 80B are plan views showing a relation between
the processed region and solution flow according to a 37th
embodiment;
[0182] FIG. 81 is a diagram showing a total defect area in the
processed region after formation of the processed region with
respect to v/f.sup.2;
[0183] FIG. 82 is a plan view showing the shape of the irradiation
region on the substrate according to a 38th embodiment;
[0184] FIG. 83 is a characteristic diagram showing a total particle
area with respect to total extension of a side according to the
38th embodiment; and
[0185] FIGS. 84A to 84D are diagrams showing a modification example
of the irradiation region according to the 38th Embodiment.
DETAILED DESCRIPTION OF THE INVENTION
[0186] Embodiments of the present invention will be described
hereinafter with reference to the drawings.
FIRST EMBODIMENT
[0187] FIGS. 1A to 1G are sectional views showing manufacturing
steps of a semiconductor device according to a first embodiment of
the present invention. As shown in FIG. 1A, a substrate 100 is
prepared. For the substrate 100, an alignment mark 102 is
buried/formed in a semiconductor substrate 101 of Si. An interlayer
insulating film 104 is formed so as to coat wiring patterns 103
formed on the semiconductor substrate 101. The wiring patterns 103
are formed in a device region, and the alignment mark 102 is formed
in the periphery of the device region.
[0188] Subsequently, as shown in FIG. 1B, an anti-reflection film
105 having a film thickness of 100 nm, and a chemical amplification
positive resist film 106 having a film thickness of 300 nm are
successively formed on the interlayer insulating film 104. The
anti-reflection film 105 is formed of an organic material in a
rotary application method. The chemical amplification positive
resist film 106 is a resist for an ArF light (wavelength 193
nm).
[0189] It is necessary to selectively remove the anti-reflection
film 105 and resist film 106 on the alignment mark 102 which has a
low transmittance with respect to an exposure light before
performing alignment by an ETTR alignment method.
[0190] A region including the alignment mark 102 to be observed by
the ETTR alignment method has a size, for example, of 100
.mu.m.times.200 .mu.m. Therefore, an opaque film of this region of
100 .mu.m.times.200 .mu.m is removed.
[0191] Next, a constitution of a laser processing apparatus for
selectively removing the anti-reflection film 105 and resist film
106 on the alignment mark 102 will be described. FIG. 2 is a
diagram showing the constitution of an optical processing apparatus
according to the first embodiment of the present invention.
[0192] As shown in FIG. 2, an optical processing apparatus 200
includes a laser optical system 210, observation system 220, and
laser processing section 230. First, the constitution of the laser
optical system 210 will be described.
[0193] The laser optical system 210 includes: a laser oscillator
211; a laser oscillator control unit 212 which controls the laser
oscillator 211; an optical system 214 which controls a laser beam
213 oscillated from the laser oscillator 211; an optical shaping
unit 215 which controls a shape of the laser beam 213 passed
through the optical system 214; and a condenser lens 216.
[0194] The laser beam 213 emitted from the laser oscillator 211 is
successively transmitted through the optical system 214, optical
shaping unit 215, and condenser lens 216, and a processing surface
100a of the substrate 100 disposed in the laser processing section
230 is exposed. The observation system 220 is inserted between the
optical shaping unit 215 and condenser lens 216.
[0195] For example, a Q-Switch Nd-YAG laser oscillator is used as
the laser oscillator 211. The laser beam oscillated from this
Q-Switch Nd-YAG laser oscillator includes a basic wave (wavelength
1064 nm), second higher harmonic wave (wavelength 532 nm), third
higher harmonic wave (wavelength 355 nm), and fourth higher
harmonic wave (wavelength 266 nm). A wavelength which is absorbed
by a film to be removed is selected from these wavelengths, and the
substrate 100 is exposed with the laser beam having the selected
wavelength.
[0196] Furthermore, a pulse width of the laser beam 213 emitted
from the laser oscillator 211 is set to about 10 nsec. Moreover, it
is possible to oscillate the laser beam of the laser oscillator 211
at 10 kHz at maximum. The oscillation of the laser beam 213 of the
laser oscillator 211 is controlled by the laser oscillator control
Unit 212.
[0197] The laser beam 213 emitted from the laser oscillator 211 is
incident upon the optical shaping unit 215 via the optical system
214.
[0198] As shown in FIG. 3, the optical shaping unit 215 is
constituted of two systems: a view field setting system 250 in
which an aperture for setting a view field; and a slit/dot setting
system 260 in which an aperture for further miniaturizing the view
field is formed. The substrate 100 is irradiated with the laser
beam transmitted through a portion in which the aperture formed in
the view field setting system 250 overlaps with that formed in the
slit/dot setting system 260.
[0199] The view field setting system 250 forms the shape of the
laser beam in a direction crossing at right angles to a scan
direction described later. Moreover, the slit/dot setting system
260 forms the shape of the laser beam of the scan direction.
[0200] The constitution of the view field setting system 250 will
be described with reference to FIG. 4. FIG. 4 is a diagram showing
the constitution of a view field diaphragm setting system according
to the first embodiment. As shown in FIG. 4, a plurality of, for
example, four view field diaphragms 252a to 252d are mounted on a
view field diaphragm mount plate 251. When the view field diaphragm
mount plate 251 is rotated with a view field diaphragm selection
mechanism 254, the diaphragm is selected from the view field
diaphragms 252a to 252d.
[0201] A view field diaphragm rotation mechanism 255 for rotating
the view field diaphragms 252a to 252d is disposed on the view
field diaphragm mount plate 251. As shown in FIGS. 5A and 5B, the
diaphragm rotation mechanism 255 rotates the view field diaphragm
252 by an angle .theta.2 corresponding to an inclination .theta.1
of the alignment mark of the substrate 100, which is measured by
the observation system 220.
[0202] Moreover, as another mode of the view field setting system,
a view field diaphragm system of a diaphragm blade type shown in
FIG. 6 may also be used. This view field diaphragm system is
shielded by four diaphragm blades 256a to 256d, and the laser beam
is transmitted and shaped through a region surrounded by the
diaphragm blades 256a to 256d. With the diaphragm type, it is
possible to vary the shaping system shape of the laser beam.
[0203] The constitution of the slit/dot setting system 260 will be
described with reference to FIGS. 7 and 8. FIGS. 7 and 8 are
diagrams showing the constitution of the slit/dot setting system
according to the first embodiment of the present invention.
[0204] As shown in FIG. 7, a second rotary plate 262 is disposed on
a first rotary plate 261. A slit/dot diaphragm mount plate 263
(FIG. 8) on which the diaphragms are mounted is disposed on the
second rotary plate 262. First and second rotation mechanisms 264,
265 are disposed to rotate the first and second rotary plates 261
and 262, respectively.
[0205] As shown in FIG. 8, for example, four diaphragms 266a to
266d are mounted on the slit/dot diaphragm mount plate 263. A
translatory movement mechanism 267 translates/moves the slit/dot
diaphragm mount plate 263 to select any one from the slit/dot
diaphragms 266a to 266d.
[0206] Examples of four slit/dot diaphragms 266a to 266d are shown
in FIGS. 9A to 9D. The diaphragm 266a shown in FIG. 9A transmits
the laser beam shaped by the view field setting system 250
substantially as such. The diaphragm 266b shown in FIG. 9B shapes
the beam in a slit shape. The diaphragms 266c, 266d shown in FIGS.
9C and 9D form the laser beams in dot shapes.
[0207] When the amount of a gas generated by laser exposure is
high, the laser beam is scattered by the generated gas, and the
processing is influenced in this manner, the slit shape may be
used. Furthermore, when this tendency is remarkable, divided slit
shapes may be used. When the above-described influence is little, a
checkered lattice may be used. It is to be noted that a processing
situation of a processed film is observed beforehand, and only one
of these diaphragms can be mounted.
[0208] It is to be noted that the slit shape described herein
indicates a shape in which a longitudinal direction of the
irradiation shape is substantially equal to one side of the
processed region, and a width, in the direction crossing at right
angles to the longitudinal direction, is shorter than the other
side of the processed region. Moreover, the irradiation shape of
the dot shape indicates that both widths of the direction crossing
at right angles to the irradiation shape are shorter than the width
of the direction crossing at right angles to the processed
region.
[0209] In this slit/dot diaphragm setting system, while the
substrate stands still, the translatory movement mechanism 267 can
translate/move the diaphragm mount plate 263 to scan the region to
be exposed on the substrate. Since the plate is moved slightly by
about several micrometers, a piezoelectric device may also be used
to vibrate the plate in a translatory direction. It is to be noted
that the slit may be fixed in the same method as that for use in a
related-art exposure apparatus and the substrate and may also be
relatively scanned against laser beam.
[0210] The first and second rotation mechanisms 264, 265 rotate the
diaphragm mount plate 263 by an angle .theta.3 corresponding to the
inclination .theta.1 of the alignment mark of the substrate 100,
measured by the observation system 220, and adjust an irradiation
position of the laser beam shaped by the view field setting system
250.
[0211] The aperture of the view field diaphragm for use herein has
a shape substantially analogous to that of the processed region.
The aperture is prepared in accordance with the processed region in
a range of 10 .mu.m to 500 .mu.m 10 .mu.m.times.10 .theta.m to 500
.mu.m.times.500 .mu.m) of one side of the exposure region on the
substrate. Moreover, the slit/dot diaphragm for use has a slit or
dot width W of 2 to 10 .mu.m. A plurality of slit/dot diaphragms
are prepared in a range of a pitch P=2 W to 100 W. A throughput or
particle generated amount is obtained beforehand, and the
diaphragms are selectively used.
[0212] It is to be noted that as shown in FIG. 10, a mechanism
similar to the view field setting system 250 may also be used to
select a diaphragm plate in which the slits or dots are formed.
[0213] Another constitution of the slit/dot setting system 260 will
be described with reference to FIG. 10. FIG. 10 is a diagram
showing the constitution of the slit/dot setting system according
to the first embodiment. As shown in FIG. 10, a plurality of, for
example, four slit/dot diaphragms 266a to 266d shown in FIGS. 9A to
9D are mounted on the S/D diaphragm mount plate 267. An S/D
diaphragm selection mechanism 269 rotates the S/D diaphragm mount
plate 267 to select any one from the slit/dot diaphragms 266a to
266d.
[0214] An slit/dot diaphragm rotation mechanism 268 for rotating
the S/D diaphragms 266a to 266d is disposed on the slit/dot
diaphragm mount plate 267. The slit/dot diaphragm rotation
mechanism 268 rotates the slit/dot diaphragm 252 by the angle
.theta.3 corresponding to the inclination .theta.1 of the alignment
mark of the substrate 100, measured by the observation system
220.
[0215] When the S/D setting system shown in FIG. 10 is used, a
driving mechanism 242 moves the substrate 100 in parallel to change
the irradiation position of the substrate. It is to be noted that a
reflective plate such as a mirror is disposed between the substrate
and view field setting system to change the angle of the reflective
plate, and the irradiation position in the substrate can also be
changed.
[0216] In this manner, an optical image shaped by the optical
shaping unit 215 is transmitted through the observation system 220
and condenser lens 216 to irradiate the processing surface 100a of
the substrate 100. The observation system 220 includes a half
mirror 221 for taking the laser beam 213 from a light axis, and a
camera for observation 222 for observing the laser beam taken out
by the half mirror 221. For the observation system 220, a position
to be processed on the substrate 100, exposing position, and
processing situation are recognized as image information via the
CCD camera 222.
[0217] This observation system 220 can be used to perform alignment
adjustment of the laser beam irradiation position. Moreover, the
process of the laser beam irradiation comprises: successively
recognizing the image for the processed state; extracting the
region to be processed from the image; and judging progress of the
processing to adjust an exposure amount. For example, the exposure
amount is reduced in the portion that the progress of processing is
fast, and the exposure amount is increased in the portion that the
progress of processing is fast. Moreover, it is recognized whether
the processing ends. A difference of the image is obtained to
recognize end of the processing. In a stage in which the difference
of the image of the whole region to be exposed is substantially 0,
the processing is ended. The processing can be controlled in this
manner.
[0218] The observation system 220 also serves as a particle
detection mechanism for observing the whole region to be exposed of
the substrate 100 to count particles. The particles can be detected
by calculating the number of pixels of a specific gradation range
in a reflected light received by a CCD pixel. Furthermore, by an
algorithm of:
1) regarding pixels disposed adjacent to each other longitudinally
and laterally as one cluster to determine the number of defects;
and
[0219] 2) also regarding pixels disposed adjacent to each other
longitudinally, laterally, and obliquely as one cluster to
determine the number of defects, the defects can also be extracted.
The particle detection mechanism compares the number of calculated
defects with the minimum number of defects registered beforehand.
When the number of detected defects is more than the minimum number
of defects, a command is issued so as to successively perform
treatment in a desired region. When the number is not more than the
minimum number of defects, control can be executed to issue a
command for shifting to the next processed region.
[0220] Moreover, the image is stored before/after laser exposure.
When the difference is taken and is substantially 0, the processing
in the portion is stopped. In another case, the control is executed
to continue the processing.
[0221] Next, the laser processing section 230 will be described. A
holder 231 is constituted in a tray-like shape in which a dam for
storing a solution 239 is disposed in a peripheral portion. For
example, pure water is used as the solution 239.
[0222] A stage 232 in which the substrate 100 can be laid/held is
disposed in a middle portion in the holder 231. The substrate 100
is rotated by a rotation mechanism 233 connected to the stage 232.
For the rotation of the substrate 100, a rotary angle is controlled
by a sensor 235 and rotation control mechanism 234. It is to be
noted that in the present embodiment the rotation mechanism 233 is
connected to a driving mechanism 242. The holder 231 is moved in
horizontal and vertical directions to change the exposure position
of the laser beam. The condenser lens 216 can be miniaturized by
the rotation mechanism 233 and driving mechanism 242. It is
possible to miniaturize a laser processing system in this
manner.
[0223] The holder 231 further includes a window 236 for covering
the solution in which the processing surface of the substrate 100
is submerged. The window is transparent to the laser beam. The
laser beam 213 oscillated from the laser oscillator 211 is
transmitted through the window 236 and solution 239 so that the
processing surface 100a of the substrate 100 is exposed.
[0224] Furthermore, a solution flow unit 237 is disposed to allow
the solution 239 pooled in the holder 231 to flow. The solution
flow unit 237, which is basically a pump, is connected to the
holder 231 through pipes 238a, 238b, and the solution 239 is
circulated. Moreover, a flow direction can be controlled with
respect to the direction of relative movement of the substrate 100
and laser beam.
[0225] Additionally, the present apparatus includes a piezoelectric
device 240 disposed in the back surface of the holder 231, and a
piezoelectric device driving control circuit 241 which controls the
driving of the piezoelectric device 240. The piezoelectric device
240 gives an ultrasonic vibration to the solution 239 of the
irradiation region of the laser beam of at least the processing
surface 100a of the substrate 100, and bubbles generated by the
irradiation with the laser beam can be removed.
[0226] Moreover, a laser beam source is used as a light source for
the processing in the present apparatus, but the present invention
is not limited to this. Any light may be used, as long as a
wavelength is absorbed by the film to be processed and desired
processing can be performed, that is, the film thickness can be
reduced, or the film can be removed. For example, when the
wavelength is absorbed by a visible or ultraviolet region in an
organic or inorganic film, the light of a tungsten or Xe flash lamp
is condensed and used. In this case, film thickness reduction is
confirmed.
[0227] The present apparatus relates to the processing in water,
but can also be applied to a treatment in the atmosphere,
pressurizing treatment, and reduced pressure treatment, and the
holder structure can be used in accordance with the respective
treatments.
[0228] Next, the removing of the resist film 106 and
anti-reflection film 105 using the optical processing apparatus 200
will be described.
[0229] The substrate is transferred to the optical processing
apparatus 200 shown in FIG. 2. A notch and wafer edge of the
substrate are detected to adjust alignment of a laser beam axis and
substrate. Moreover, the inclination of the view field diaphragm
and Slit/dot diaphragm is adjusted in accordance with the
inclination of the alignment mark 102.
[0230] Next, for the shape of the light to be emitted, a
predetermined region to be removed is determined to have a
longitudinal size 100 .mu.m.times.lateral size 200 .mu.m, and the
optical shaping unit is used to shape the laser beam in a desired
shape. Moreover, in the present embodiment, the Slit/dot diaphragm
for shaping the laser beam in one slit shape with a longitudinal
size 100 .mu.m.times.lateral 5 .mu.m is used.
[0231] Next, as shown in FIG. 1C, the solution flow unit 237 is
operated to allow the solution 239 to flow between the window 236
and substrate 100. In this state, the laser beam is relatively
scanned against the substrate to remove the region to be processed
of the film.
[0232] A method of relatively scanning the substrate against light
may comprise: fixing the light axis of the laser beam to use the
driving mechanism 242; or using the optical shaping unit and
translating/moving, for example, the Slit/dot mount plate 263 to
scan the substrate.
[0233] The wavelength of the laser beam is absorbed by the
anti-reflection film for use in a lithography process. An energy
density per pulse is appropriately adjusted so that the whole
region to be ablated can satisfactorily be removed without damaging
a region other than the whole region to be ablated. The energy
density per pulse is usually in a range of 0.1 J/cm.sup.2pulse to
0.5 J/cm.sup.2pulse.
[0234] Since the solution 239 exists on the exposure portion at a
laser beam exposure, heat generated by the exposure with the laser
beam can be removed in the processing surface 100a of the substrate
100. Furthermore, an energy of evaporant generated by the
irradiation with the laser beam can be decreased.
[0235] The window 236 prevents the solution 239 pooled in the
holder 231 from being scattered at a laser processing time.
Moreover, the window prevents dust from sticking to the surface of
the semiconductor substrate 101 from above.
[0236] The substrate 100 is exposed with the laser beam, and the
Slit/dot diaphragm mount plate 263 is translated/moved. When the
Slit/dot diaphragm mount plate 263 is translated/moved, as shown in
FIG. 11, an exposure region 272 with the laser beam relatively
scans against the whole region to be exposed 271 on the substrate,
and the anti-reflection film 105 and resist film 106 of the whole
region to be exposed are removed.
[0237] It is to be noted that the particles generated at exposure
by the exposure are removed in the liquid flow. It has been
confirmed by experiments that the particles stick onto a downstream
side. Then, for a scan direction of the exposure region, the
generated particles can be removed in the same direction as that of
the liquid flow during the processing. Therefore, the generation of
the particles is reduced. The solution flow unit 237 allows the
solution 239 pooled in the holder 231 to flow so that bubbles
generated in the irradiation position of the laser beam by the
irradiation with the laser beam can continuously be removed.
Furthermore, the solution is circulated in a constant direction in
a constant flow rate so as to prevent irregular disturbance from
being generated in the laser beam. The solution flow unit 237 may
be driven, when the laser processing is actually performed.
[0238] Next, after the solution 239 pooled in the holder 231 is
discharged, the processing substrate 100 is rotated at a high
speed, and a liquid in the surface is roughly removed. Thereafter,
the processing substrate 100 is further transferred to a second
solvent removing apparatus and heated. A heating temperature of the
substrate 100 was set to 200.degree. C. The substrate 100 is heated
here in order to remove an adsorbed liquid in the surface of a
resist film 306 and to obtain the same exposure environment in the
whole resist film surface. When the treatment is not performed,
acid generated in the exposure moves by a slight amount of liquid
left in the film in a portion in contact with the liquid, and a
pattern defect is caused.
[0239] Subsequently, the substrate 100 is transferred to an
exposure apparatus. As shown in FIG. 1D, the alignment mark 102 of
the substrate 100 is detected by an alignment detector using an
alignment light (first energy line) 107 which has the same
wavelength as an exposure wavelength. At this time, since the
anti-reflection film 105 on the alignment mark 102 is removed,
satisfactory detection sensitivity is obtained. It is to be noted
that the alignment mark 102 cannot be detected, when the
anti-reflection film 105 on the alignment mark 102 is not removed
as in the related art.
[0240] As shown in FIG. 1E, an exposure portion 106a of the resist
film 106 is irradiated with an exposure light (second energy line)
to form a latent image of a circuit pattern in the resist film 106.
After the latent image forming step, the substrate 100 is
transferred to a heating apparatus for a PEB step to perform a
heating treatment (PEB) of the processing substrate. The heating
treatment is performed to cause catalyst reaction of acid of a used
resist (chemical amplification type resist).
[0241] After this heating treatment, as shown in FIG. 1F, the
substrate 100 is transferred to develop the image of the resist
film 106 and to form resist patterns 109. Alignment precision of
the formed resist patterns 109 is not more than .+-.5 nm.
[0242] Subsequently, as shown in FIG. 1G, the resist patterns 109
are used as masks to etch the anti-reflection film 105 and
interlayer insulating film 104 by RIE.
[0243] FIG. 12 shows a substrate surface state from which the
anti-reflection film 105 and resist film 106 are removed in the
above-described method. Moreover, FIG. 13 shows the substrate
surface state as a reference example in a case in which the laser
is collectively exposed the whole region to be ablated the films
are removed.
[0244] As seen from FIG. 13, when the films are removed by the
collective exposure, a large number of particles 284 exist and
cannot completely be removed in the periphery and inside of the
whole region to be ablated. Furthermore, peels 283 of the resist
film formed on the anti-reflection film are generated around the
whole region to be ablated.
[0245] When the films are removed in the method of the present
embodiment, as compared with the related-art method shown in FIG.
13, peels 281 of the upper-layer resist are reduced. It is seen
that the number of particles 282 sticking to the periphery and
inside of the whole region to be ablated decreases.
[0246] A reason of the decrease of the number of particles will be
described hereinafter. When a exposure region once is broad, the
bubble generated: by the exposure becomes larger than the whole
region to be ablated. Therefore, a large number of particles
adsorbed in bubble surfaces stick to the inside/outside of the
whole region to be ablated.
[0247] On the other hand, when the exposure-region is thinned into
the slit shape, and the exposure region is relatively scanned
against the whole region to be ablated on the substrate, the bubble
generated once becomes small, and the bubble does not easily
contact the substrate. Therefore, the number of particles sticking
to the inside/outside of the whole region to be ablated is
reduced.
[0248] As a result of measurement of the generated bubble, in a
case in which a whole region to be ablated of the film is
collectively removed, a radius of the generated bubble was R=120
.mu.m. On the other hand, in the exposure with the laser beam
having the slit shape with a width of 5 .mu.m, the bubble radius
was R=25 .mu.m. In the exposure with the laser beam having the slit
shape, the size of the bubble is reduced as compared with the
collective exposure. It has been seen from this result that the
diameter of the bubble generated with one ablation is controlled to
be reduced, and the sticking particles can be reduced.
[0249] However, even the above-described method is incomplete for
removing the particles in the processed region. The sticking
particles in the alignment mark cause problems of an increase of
read inaccuracy in reading the alignment mark, or read error.
Moreover, when the particles stick to the outside of the alignment
mark, particularly to a device region, a pattern forming defect is
caused, and yield disadvantageously drops.
[0250] A method in which the number of particles sticking to the
inside/outside of the whole region to be ablated can further be
reduced will be described hereinafter.
[0251] First, a processing method for preventing the particles from
sticking to the inside of the whole region to be ablated will be
described. An apparatus for use in removing the film is similar to
that described in the first embodiment.
[0252] FIGS. 14A and 14B are sectional views showing the
manufacturing steps of the semiconductor device according to the
first embodiment of the present invention.
[0253] As shown in FIG. 14A, for the resist film and
anti-reflection film on a predetermined the whole region to be
ablated (longitudinal 100 .mu.m.times.lateral 200 .mu.m), a laser
beam 110 is shaped in the slit shape (longitudinal 100
.mu.m.times.lateral 3 .mu.m) having a width smaller than that of
the alignment mark, and is exposed with the resist film and
anti-reflection film. While the laser beam (first processing light)
110 is scanned to the other end from one end of the processed
region, the ablation is performed. At this time, a small amount of
particles 111 stick to the substrate surface.
[0254] Here, assuming that an oscillation frequency is f, scan
speed is v, and a slit having a width t is scanned, the number n of
overlap exposures performed in one scan is represented by: n=tf/v
(1) That is, when the oscillation frequency f 250 Hz, and scan
speed v=30 .mu.m/sec, the number n of overlap exposures=25
irradiations in the slit width t=3 .mu.m.
[0255] When the number n of overlap exposure increases, damages by
exposure are easily caused in various regions formed in the lower
layer of the anti-reflection film, such as a substrate Si, mark,
and interlayer insulating film. That is, the number of overlap
exposures is appropriately selected by the thickness and material
of the anti-reflection film or the film type or thickness of the
anti-reflection film lower layer. Usually n is selected between 1
and 50.
[0256] In equation (1), when the number n of overlap exposures is
less than one, the overlap of the exposure regions is removed. A
film which cannot completely be removed exists in the whole region
to be ablated. This residual film in the whole region to be ablated
is peeled, when the adjacent exposure region is exposed. Critical
particles are generated. That is, n needs to be set to at least 1
or more.
[0257] Subsequently, as shown in FIG. 13B, a laser beam (second
processing light) 112 is scanned to the other end from one end.
Furthermore, when the laser beam 112 is similarly repeatedly
reciprocated/scanned, it is possible to remove the particles
remaining above the alignment mark. Here, the scanning was
performed in the solution 239 pooled in the holder 231 in order to
alleviate an influence onto the resist film by the heat generated
by the abrasion. Moreover, the solution 239 was circulated in the
constant direction at the constant flow rate so that the bubbles
generated in the region irradiated with the laser beam by the
irradiation with the laser beam can continuously be removed and to
such an extent that disturbance is not generated in the laser beam
in the solution flow unit 237.
[0258] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0259] It has been confirmed that the alignment precision of the
substrate pattern with the exposure pattern is improved by the
above-described step.
[0260] In the present embodiment the processed film on: the
alignment mark is completely removed, but the present invention is
not limited to this embodiment. For example, when the alignment
mark can be detected by the optical system for use in the alignment
measurement, the processing may be ended even with a slight amount
of the processed film remaining in the whole region to be ablated.
For example, even when the film thickness of the processed film is
halved, and contrast is bad, the alignment can be performed.
SECOND EMBODIMENT
[0261] In the first embodiment, the method of forming the exposure
region of the laser beam in the slit shape and
reciprocating/scanning the laser beam against the whole region to
be ablated to remove the particles sticking to the whole region to
be ablated has been described.
[0262] However, at the processing by the exposure in this method,
the exposure region on the substrate is constantly fixed in the
slit shape having a constant area, and the light is
reciprocated/scanned in the whole region to be ablated. Therefore,
when the alignment precision is not sufficient with respect to the
exposure position and the whole region to be ablated, and every
time the reciprocating scan is repeated, the processed position
deviates. This causes a problem that the particles are newly
generated from a edge of the whole region to be ablated.
[0263] To solve the problem, in the present embodiment, a method
will be described which comprises: reducing the exposure region of
the laser beam on the substrate in consideration of the alignment
precision in the vicinity of the edge of the whole region to be
ablated and reducing the number of the particles generated in the
vicinity of the edge of the whole region to be ablated to prevent
the particles from sticking to the processed region.
[0264] FIGS. 15A, 15B, 16A and 16B are diagrams showing the
manufacturing steps of the semiconductor device according to a
second embodiment of the present invention. It is to be noted that
in FIGS. 15A, 15B, 16A and 16B, the same parts as those of FIG. 1B
are denoted with the same reference numerals, and the description
thereof is omitted. FIGS. 15A and 16A are sectional views, and
FIGS. 15B and 16B are plan views of the processed region.
[0265] In a first scan, as shown in FIG. 15, exposure region 120 is
relatively scanned against the substrate 100 in a middle portion of
a whole region to be ablated 121, and scanned to the other end from
one end of the whole region to be ablated to remove the
anti-reflection film 105 and resist film 106 of the whole region to
be ablated 121. It is to be noted that reference numeral 122
denotes the exposure region of the laser beam 120.
[0266] As described above, when the alignment precision of the
exposure region with the hole region to be ablated is not
sufficient in the reciprocating scan in this state in the first
embodiment, the edge of the whole first region to be ablated is
exposed, and processed, and the particles stick into the region
121.
[0267] Then, In a second and subsequent state, as shown in FIGS.
16A and 16B, when an exposure region 124 approaches the edge of the
whole region to be ablated 121, in consideration of the
alignment-precision, an exposure region 125 is set to be smaller
than the an exposure region 122 in the middle portion of the
processed region 121 by the view field setting system 250.
[0268] Thereby, new particles can be prevented from being generated
from a region other than the whole region to be ablated 121 by the
influence of the alignment error in the vicinity of the edge of the
whole region to be ablated 121. Moreover, when an exposure region
is reduced, the bubble 125 generated in the edge of the whole
region to be ablated becomes smaller than a bubble 123 generated in
the middle portion of the whole region to be ablated. Moreover, the
amount of particles 111 decreases. Therefore, the particles 111
adsorbed in the surfaces of the bubbles 125 are also prevented from
sticking to the substrate surface.
[0269] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0270] By this method, it is further possible to prevent the
particles from sticking into the processed region as compared with
the method described in the first embodiment.
[0271] In the present embodiment the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with a slight amount of
the processed film remaining in the processed region.
THIRD EMBODIMENT
[0272] In the second embodiment, the method has been described
which comprises: relatively scanning the exposure region against
the whole region to be ablated substrate; and reducing the area of
the exposure region in consideration of the alignment precision in
the vicinity of the edge of the whole region to be ablated.
Thereby, the new particles are inhibited from being generated from
the region other than the whole region to be ablated, the diameter
of the generated bubble is reduced, and the particles adsorbed in
the bubble surface are prevented from sticking to the substrate
surface.
[0273] In a third embodiment, for a purpose similar to that of the
second embodiment, the exposure region is relatively scanned
against the whole region to be ablated, and scanned to the other
end from one end of the whole region to be ablated. When the
position of exposure region comes close to the edge of the whole
region to be ablated, a scan speed is reduced, and the alignment
precision in the vicinity of the edge of the whole region to be
ablated is further improved. Moreover, when the diameter of the
bubble generated per unit time is reduced, the particles are
prevented from sticking into the whole region to be ablated. This
method will be described.
[0274] FIGS. 17A, 17B, 18A and 18B are diagrams showing the
manufacturing steps of the semiconductor device according to the
third embodiment of the present invention. It is to be noted that
in FIGS. 17A, 17B, 18A and 18B, the same parts as those of FIG. 1B
are denoted with the same reference numerals, and the description
thereof is omitted. FIGS. 17A and 18A are sectional views, and
FIGS. 17B and 18B are plan views of the processed region.
[0275] In second and subsequent scans, when the exposure region
approaches the edge of the whole region to be ablated, a scan speed
of a laser beam 133 is reduced (FIGS. 18A and 18B) as compared with
a time when a exposure region 130 is scanned in the middle portion
of a whole region to be ablated 131 (FIGS. 17A and 17B). The scan
speed of the exposure region is adjusted by adjusting a translation
rate of the diaphragm mount plate. Reference numerals 131, 134
denote the exposure region 130, 133 on the substrate.
[0276] Since the scan speed of the exposure region becomes slow in
the edge of the whole region to be ablated 131, the exposed area
per time decreases in the vicinity of the edge of the whole region
to be ablated 131. Therefore, the diameter of a bubble 135
generated in the unit time also decreases, the particles 111
adsorbed in the surfaces of the bubbles 135 do not easily contact
the substrate surface, and the particles are prevented from
sticking to the inside/outside of the whole region to be ablated
131.
[0277] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0278] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0279] In the present embodiment the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with the slight amount of
the processed film remaining in the processed region.
FOURTH EMBODIMENT
[0280] In the first embodiment, the method of scanning the thinned
laser beam constantly having the constant exposure region in the
whole region to be ablated to remove the anti-reflection film or
resist film has been described. However, when the exposure region
is reciprocated/scanned, there is an error in the alignment
precision between the laser beam and whole region to be ablated
against the scan direction. In this case, when the exposure region
having the same shape is repeatedly reciprocated/scanned, an
influence of the alignment error is exerted, and the region other
than the whole region to be ablated is exposed. As a result, every
time exposure region is reciprocated/scanned in the whole region to
be ablated, new particles are generated, and it is difficult to
completely remove the particles.
[0281] To solve the problem, in a fourth embodiment, the alignment
precision of the exposure region against the processed region is
considered, and a long side of the exposure region formed in the
slit shape is gradually reduced.
[0282] This embodiment will be described in more detail with
reference to FIGS. 19A, 19B, 20A and 20B. FIGS. 19A, 19B, 20A and
20B are diagrams showing the manufacturing steps of the
semiconductor device according to the fourth embodiment of the
present invention. It is to be noted that in FIGS. 19A, 19B, 20A
and 20B, the same parts as those of FIG. 1B are denoted with the
same reference numerals, and the description thereof is omitted.
FIGS. 19A and 20A are sectional views, and FIGS. 19B and 20B are
plan views of the processed region.
[0283] FIGS. 19A and 19B show a first scan state. Moreover, FIGS.
20A and 20B show a second and subsequent scan state. As shown in
FIGS. 19A, 19B, 20A and 20B, a length of an exposure region 144 in
the longitudinal direction in the second scan of a laser beam 143
is set to be shorter than that of an exposure region 142 of a laser
beam 140 in the first scan.
[0284] In this case, even when the reciprocating scan is repeated,
the region other than the whole region to be ablated is not exposed
with the light. As a result, it is possible to reduce the particles
generated outside the whole region to be ablated and to prevent the
particles from sticking to the film.
[0285] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0286] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0287] In the present embodiment the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with the slight amount of
the processed film remaining in the processed region.
FIFTH EMBODIMENT
[0288] In the first embodiment, the thinned light is scanned in the
whole region to be ablated to remove the anti-reflection film or
resist film. However, in this method, when there is the alignment
error of the scan direction between the exposure region and the
whole region to be ablated, and when the exposure region is
constantly reciprocated/scanned in the whole region to be ablated,
the edge of the whole region to be ablated by the previous exposure
is exposed for every repeated reciprocating scan. A large amount of
new particles are generated from the portion other than the whole
region to be ablated.
[0289] To solve the problem, in a fifth embodiment, the alignment
precision of the position of exposure region is considered with
respect to the scan direction, and a scan range of the exposure
region in the whole region to be ablated is gradually reduced every
increase of the number of scans.
[0290] This embodiment will be described in more detail with
reference to FIGS. 21 and 22. FIGS. 21 and 22 are diagrams showing
the manufacturing steps of the semiconductor device according to
the fifth embodiment of the present invention. It is to be noted
that in FIGS. 21 and 22, the same parts as those of FIG. 1B are
denoted with the same reference numerals, and the description
thereof is omitted.
[0291] FIG. 21 shows the first scan state. Moreover, FIG. 22 shows
the second scan state. As shown in FIGS. 21 and 22, the scan range
of an exposure region 151 in the second scan is set to be smaller
than that of an exposure region 150 in the first scan.
[0292] For this reciprocating scan, even when the reciprocating
scan is repeated, the region other than the whole region to be
ablated is not exposed with the light. As a result, it is possible
to reduce the particles generated outside the whole region to be
ablated and to prevent the particles from sticking to the film.
[0293] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0294] As described above, in the first to fifth embodiments, the
shape of exposure region is set to a long slit shape, and the
exposure region is relatively against the whole region to be
ablated to remove the anti-reflection film or resist film. However,
the shape of exposure region is not limited to the long slit shape.
The exposure region may be exposed with a light divided in dot
shapes, and the inside of the predetermined processed region may
also be scanned.
[0295] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0296] In the present embodiment the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
SIXTH EMBODIMENT
[0297] In the first to fifth embodiments, the method has been
described comprising: reciprocating/scanning the light whose
exposure region is smaller than the whole region to be ablated to
remove the particles sticking into the processed region.
[0298] However, this method has a problem that time is consumed in
the reciprocating scan and throughput drops. Furthermore, because
of the exposure with the light having the long slit shape, problems
occur that an influence of heat strain increases in the alignment
mark formed in the anti-reflection film lower layer and that the
lower layer is easily damaged.
[0299] In a sixth embodiment, a method of shortening a treatment
time while inhibiting the lower layer from being damaged by the
alignment mark will be described.
[0300] FIGS. 23A and 23B are sectional views showing the
manufacturing steps of the semiconductor device according to the
sixth embodiment. It is to be noted that in FIGS. 23A and 23B, the
same parts as those of FIG. 1B are denoted with the same reference
numerals and the description thereof is omitted.
[0301] As shown in FIG. 23, the method first comprises: scanning an
exposure region 160 of the slit shape against the whole region to
be ablated to remove the anti-reflection film 105 and resist film
106 of the processed region. In this state, the particles 111 exist
in the whole region to be ablated.
[0302] Subsequently, in second and subsequent exposure, as shown in
FIG. 23B, the exposure region 161 is shaped only by the view field
setting system and has substantially the same size as that of the
whole region to be ablated to remove the particles. At this time,
in consideration of the alignment precision, an actual exposure
region may also be smaller than the whole region to be ablated so
as to prevent a portion other than a the whole region to be ablated
from being generated particles.
[0303] Even in this method, in the same manner as in the second to
fifth embodiments, it is possible to prevent the particles from
sticking into the whole region to be ablated.
[0304] Moreover, here, first the exposure region is the long slit
shape and is relatively scanned against whole region to be ablated
to remove the anti-reflection film or resist film. However, the
shape of the exposure region is not limited to a thin rectangular
shape. The processed region may also be exposed with the light
divided in dots, and the dotted light may also be scanned in the
whole region to be ablated.
[0305] As described above, in at least the first processing, the
exposure region having the long slit shape is scanned to ablate the
region, so that the particles are inhibited from being generated.
Thereafter, when the processed region is exposed with the light, it
is possible to remove the particles in the whole region to be
ablated.
[0306] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the exposure, and the difference of the number of
particles is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0307] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0308] In the present embodiment the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed-region.
SEVENTH EMBODIMENT
[0309] Next, a method of removing the particles scattered to the
inside/outside of the whole region to be ablated will be
described.
[0310] FIGS. 24A to 24C are sectional views showing the
manufacturing steps of the semiconductor device according to a
seventh embodiment of the present invention. It is to be noted that
in FIGS. 24A to 24C, the same parts as those of FIG. 1B are denoted
with the same reference numerals and the description thereof is
omitted.
[0311] In the present embodiment, the substrate submerged in a
flowing liquid is exposed with the light.
[0312] As shown in FIG. 24A, an exposure region 170 shaped in the
slit shape is scanned to a first edge B1 from a first start point
M1 in the whole region to be ablated. At this time, the direction
of the flow of the solution by the solution flow unit is a
substantially antiparallel direction against the scan direction.
That is, the an exposure region 170 moves toward an upstream side
of the solution flow. Since the particles flow with the liquid
flow, the particles 111 stick in the whole region to be ablated and
on the downstream side of the liquid flow.
[0313] Next, as shown in FIG. 24B, the exposure region 170 is
scanned to a second edge B2 from a second start point M2 between
the first start point M1 and first edge B1. At this time, the flow
of the solution 239 by the solution flow unit 237 at a first
scanning is reversed.
[0314] When the exposure region is relatively scanned against the
whole region to be ablated in this manner, the whole region to be
ablated is processed. Even in this state, by the flow of the
solution 239 by the solution flow unit 237, the particles do not
exist outside the whole region to be ablated, and all remain in the
whole region to be ablated.
[0315] Subsequently, as shown in FIG. 24C, an exposure region 171
is repeatedly reciprocated/scanned in the whole region to be
ablated, and the particles remaining in the whole region to be
ablated are removed.
[0316] Moreover, by the repeated reciprocating scan, the new
particles can be prevented from being generated from the edge of
the whole region to be ablated. Therefore, as described above in
the embodiments, the view field setting system is varied in the
vicinity of the edge of the whole region to be ablated. Thereby,
the exposure region is reduced, the scan speed is reduced, and an
optimum method is appropriately selected without any sticking
particle.
[0317] Furthermore, instead of the exposure with the slit shaped
light, as described in the sixth embodiment, the shape of exposure
region is changed to the shape substantially having the size of the
whole region to be ablated, and the collective exposure may also be
performed.
[0318] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Subsequently, the image is stored
before/after the laser irradiation, and the difference of the
number of particles is obtained. When the difference is
substantially 0, the processing in the portion is stopped;
otherwise, the processing is controlled to be continuously
performed.
[0319] When the above-described method is used, it is possible to
ablate the region without any sticking particle inside/outside the
whole region to be ablated.
[0320] When the exposure region is scanned from the vicinity of the
processed region middle as in the present embodiment, the laser
beam is preferably scanned in a direction opposite to that of the
flow of the solution 239 by the solution flow unit 237 to further
inhibit the particles from sticking.
[0321] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
EIGHTH EMBODIMENT
[0322] In the method described in the second to seventh
embodiments, the generated amount of particles can be reduced.
However, an area which can be ablated once is small, a scan time
for the whole region to be ablated is consumed, and this causes a
problem that the throughput largely drops.
[0323] To solve the problem, in the present embodiment, on order to
largely shorten the treatment time, a mask in which a plurality of
slit-shaped or dot-shaped apertures of the slit/dot diaphragm
system are disposed is used to shape the laser beam. Examples of
the mask are shown in FIGS. 25A to 25C. FIGS. 25A to 25C are plan
views showing the masks mounted in the Slit/dot diaphragm system
according to an eighth embodiment of the present invention. In
masks 180a, 180b shown in FIGS. 25A and 25B, a plurality of
slit-shaped apertures 181a, 181b are formed. Moreover, a plurality
of dot-shaped apertures 181c are formed in a mask 180c shown in
FIG. 25C.
[0324] When a pitch of a plurality of apertures disposed in the
mask is less than twice the length of the aperture of a pitch
direction, the lights passed through the adjacent apertures
diffract each other. As a result, since the substrate is exposed
with an interference light, abnormality is caused in the processed
shape.
[0325] Therefore, the pitch of the plurality of apertures disposed
in the mask is preferably not less than twice the length W of the
aperture of the pitch direction. The light having the shape
analogous to that of the aperture formed in the mask is incident
upon the substrate.
[0326] The pitch of the plurality of apertures disposed in the mask
which are adjacent to each other in the scan direction is set to be
1/2 or less of the length of the whole region to be ablated of the
scan direction. Thereby, the treatment time can be shortened.
[0327] It is to be noted that the lights interfere with each other
even with the pitch of 2 W or more and the irradiation shape cannot
be kept to be rectangular. In this case, the pitch may set to be
large.
[0328] Furthermore, it is preferable to adjust the pitch of the
apertures disposed adjacent to each other in the scan direction in
the mask so that the pitch of the processing lights emitted
adjacent to each other in the scan direction on the substrate is
larger than a diameter of the bubble generated by the irradiation
with the processing light. The pitch of the processing lights which
is disposed adjacent to each other in the scan direction and with
which the substrate is irradiated is not more than the diameter of
the bubble generated by the irradiation with the processing light.
Then, the bubbles generated adjacent to each other contact each
other. As a result, irregular disturbance is further caused in the
laser beam, and it becomes difficult to accurately process the
region.
[0329] FIGS. 26A and 26B are sectional views showing the
manufacturing steps of the semiconductor device according to the
eighth embodiment of the present invention. In FIGS. 26A and 26B,
the same parts as those of FIG. 1B are denoted with the same
reference numerals and the description thereof is omitted.
[0330] As shown in FIGS. 26A and 26B, a plurality of slit-shaped
laser beams 180, 181 are reciprocated/scanned in the whole region
to be ablated to remove the anti-reflection film 105, resist film
106, and particles 111.
[0331] For the processing, the slit/dot diaphragm may be fixed and
the substrate may be moved to process the whole region to be
ablated by the relative scan. Here, the substrate is fixed and the
slit/dot diaphragm is moved to remove the whole region to be
ablated.
[0332] Since the distance to scan the each exposure region is
reduced, a time required for processing the whole region to be
ablated is reduced in inverse proportion to the number of disposed
slits.
[0333] Moreover, by the repeated reciprocating exposure, the
particles sticking to the whole region to be ablated are removed.
Thereby, the particles can be prevented from sticking into the
processed region, and additionally the treatment time can largely
be shortened.
[0334] In this process, the observation system 220 constituted of
the CCD camera is used to count the particles inside/outside the
whole region to be ablated. Moreover, the image is stored
before/after the, and the difference is obtained. When the
difference is substantially 0, the processing in the portion is
stopped; otherwise, the processing is controlled to be continuously
performed.
[0335] Moreover, here, a plurality of slit-shaped exposure regions
are relatively scanned against the whole region to be ablated to
remove the anti-reflection film or resist film. However, the shape
of the exposure region is not limited to the slit shape. As shown
in FIG. 25C, a plurality of dot-shaped divided regions may be
disposed and reciprocated/scanned within the processed region.
[0336] Additionally, with the arrangement of the dot shapes, light
intensity weakens in the edge of the multi-slit exposure region,
the multi-slit exposure region is scanned, and an unprocessed
region is formed in a long-side direction in the whole region to be
ablated. At this time, the dots are arranged so that the long sides
of the dots overlap with each other at scanning. When the plurality
of dots are arranged in this manner, the processing is possible
without any unprocessed region or without any particle sticking
onto the treated substrate.
[0337] In the present embodiment, as shown in FIGS. 26A and 26B,
the exposure region is reciprocated/scanned to remove the whole
region to be ablated, but the present invention is not limited to
this. Even when the exposure region 180, 181 are scanned in any one
direction for periods twice the number of reciprocations performed
in FIGS. 26A and 26B, the processed surface is exposed with the
same amount of beams. At this time, the length of the scan
direction of the region in which a plurality of slits are formed in
the slit/dot diaphragms is preferably not less than the
predetermined number of scans of the whole region to be ablated
multiplied by the length of the scan direction of the aperture of
the view field diaphragm. The length of the region in which the
slits are formed is set by multiplying the length of the aperture
analogous to the whole region to be ablated by the number of scans.
Then, the necessary number of scans of the laser beam can be
performed without stopping the slit/dot diaphragm. When the
processing is performed without stopping the slit/dot diaphragm,
the reciprocating movement of the slit/dot diaphragm and the
adjustment of the laser beam can be omitted, and the processing
time can be shortened.
[0338] Therefore, the pitch of the plurality of apertures arranged
in the mask is preferably twice or more times the length W of the
aperture of the pitch direction. The light having the shape
analogous to that of the aperture formed in the mask is incident
upon the substrate.
[0339] At this time, in consideration of the alignment precision,
the scan speed of the multi-slits in the vicinity of the boundary
or the predetermined processed region, and irradiation energy or
area in the irradiation region are controlled to prevent the
particles from being generated. For the method, in consideration of
the generated situation of the particles and arrangement of the
slits, an optimum method may appropriately be selected.
[0340] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0341] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
NINTH EMBODIMENT
[0342] In a ninth embodiment, a method of shortening the treatment
time and additionally removing the particles flied/scatted
inside/outside the whole region to be ablated will be
described.
[0343] FIGS. 27A, 27B and 28 are sectional views showing the
manufacturing steps of the semiconductor device according to the
ninth embodiment of the present invention. In the present
embodiment, the substrate submerged in the flowing liquid is
irradiated with the light.
[0344] As shown in FIG. 27A, a multi-slit exposure region R is
reciprocated/scanned between the first start point in the whole
region to be ablated and first end (edge 1). At this time the
direction of the liquid flow is changed in accordance with the scan
direction so that the scan direction is antiparallel the direction
of the liquid flow. In this state, since the particles flow in the
liquid flow, the particles stick in the whole region to be ablated
and on the downstream side of the liquid flow.
[0345] The start point is set so that an interval between the start
point and the end of whole region to be ablated on a first scan
direction side is not less than the width of the multi-slit
exposure region R. If the interval is not more than the width of
the multi-slit exposure region R, the outside of the processed
region is processed.
[0346] Subsequently, as shown in FIG. 27B, the multi-slit exposure
region R is reciprocated/scanned to the other end (edge 2) disposed
opposite to a edge 1 of the whole region to be ablated from the
second start point. The direction of the liquid flow is changed in
accordance with the direction of the scan so that the direction of
the scan is antiparallel that of the liquid flow (the direction of
the liquid flow is reverse to the direction to the first boundary
from the first start point). Even in this state, since the
particles flow in the liquid flow, the particles do not stick to
the outside of the processed region, and all remain in the whole
region to be ablated.
[0347] Subsequently, as shown in FIG. 28, a laser beam 190 having
substantially the same size as that of the processed region is
emitted. By the irradiation with the laser beam 190, the particles
which cannot completely be removed by the reciprocating scan of the
multi-slit irradiation region R and which remain in the processed
region are removed.
[0348] In the processing process, the observation system 220
constituted of the CCD camera is used to count the particles
inside/outside the processed region. Moreover, the image is stored
before/after the exposure, and the difference is obtained. When the
difference is substantially 0, the processing in the portion is
stopped; otherwise, the processing is controlled to be continuously
performed.
[0349] In the present embodiment, the exposure region in the second
and subsequent exposure is changed/reduced by focus shift, but the
present invention is not limited to this. For example, a zoom
function is imparted to the image forming optical system 216 of
FIG. 2, and magnification in the second and subsequent exposure may
be slightly reduced for the exposures.
[0350] With the use of the above-described method, the multi-slits
are used to remarkably shorten the treatment time, and the
processed shape can be obtained without any sticking particle
inside/outside the whole region to be ablated.
[0351] Even when the laser processing is performed in the
atmosphere, high-pressure air or low-pressure air the effect of the
present embodiment can be confirmed.
[0352] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
TENTH EMBODIMENT
[0353] FIGS. 29A and 29B are sectional views showing the
manufacturing steps of the semiconductor device according to a
tenth embodiment of the present invention. It is to be noted that
in FIGS. 29A and 29B, the same parts as those of FIG. 1B are
denoted with the same reference numerals and the description
thereof is omitted. Concretely, a pressure control unit is added to
the air current unit shown in FIG. 2, and the processed region of
the circulated solution is controlled.
[0354] As shown in FIGS. 29A and 29B, in a state in which a
pressure of 10 atm is added to the substrate, exposure region 300,
301 shaped in the slit shapes are reciprocated/scanned against the
substrate to remove the whole region to be ablated of the
anti-reflection film 105 and resist film 106.
[0355] As a result, as compared with the processing in the similar
method at atmospheric pressure, the bubble diameter generated at
the exposing can be reduced, and the number of particles sticking
to the inside/outside of the whole region to be ablated can be
remarkably reduced.
[0356] In the processing process, the observation system 220
constituted of the CCD camera is used to count the particles
inside/outside the processed region. Moreover, the image is stored
before/after the exposure, and the difference is obtained. When the
difference is substantially 0, the processing in the portion is
stopped; otherwise, the processing is controlled to be continuously
performed.
[0357] Moreover, also in the present embodiment, in the same manner
as in the above-described other embodiments, in consideration of
the alignment precision of the whole region to be ablated against
the position of exposure region, in order to prevent the edge of
the whole region to be ablated from being exposed and to prevent
new particles from being generated, the area of the exposure region
can be reduced in the edge of the whole region to be ablated.
Alternatively, the scan speed of the exposure region against the
whole region to be ablated is reduced. For the method, an optimum
method is appropriately selected in which only a small amount of
particles stick.
[0358] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
ELEVENTH EMBODIMENT
[0359] In an eleventh embodiment, a method will be described
comprising: considering the alignment precision of the poison of
exposure region against the whole region to be ablated; and
reducing the area of the exposure region at the second and
subsequent-scans.
[0360] In the present embodiment, the method will be described
comprising: changing a focal position in which the image is formed
in the whole region to be ablated on the substrate to control the
area of the exposure region and to prevent the particles generated
from the edge of the whole region to be ablated from sticking into
the whole region to be ablated.
[0361] First, as shown in FIG. 30A, in the same manner as in the
above-described embodiments, a first processing light 311 whose
exposure region on the substrate is thinned to be smaller than the
whole region to be ablated is relatively scanned against the whole
region to be ablated to remove the anti-reflection film 105 and
resist film 106 of the processed region.
[0362] Additionally, at this time, instead of forming the image on
the anti-reflection film 105 which is a processing object, a
distance between the optical system and substrate 100 is
intentionally set so that a light distribution can spread on the
anti-reflection film 105.
[0363] Therefore, the region actually exposed with the light on the
anti-reflection film becomes larger than the region restricted by
the view field setting system. On the other hand, an energy density
per pulse weakens as the light distribution spreads. Therefore, the
energy density per pulse is appropriately controlled so as to
prevent the region having a light intensity necessary for the
processing in the spread light from having a size which is not more
than a desired size.
[0364] Instead of forming the image on the anti-reflection film 105
which is the processing object, the distance between the optical
system and substrate 100 intentionally set so that the light
distribution spreads on the anti-reflection film. At this time,
conditions of a distance D between the image forming position and
treatment substrate are as follows:
[0365] (1) the distance D is different from at least a best focus;
and
[0366] (2) it is assumed that a deviation amount between the
exposure position of the laser beam and the substrate by the
alignment error, or processing allowance is .DELTA., and the
distance D is set so as to satisfy the following equation:
D>{.DELTA.{(1-NA.sup.2).sup.1/2}/NA, wherein NA denotes a
numerical aperture of the optical system such as the condenser
lens.
[0367] In consideration of the alignment precision of the
irradiation position with the laser beam and the substrate to be
treated and the error including the influence of the fluctuation of
the solution film on the substrate to be treated, an optimum D
which satisfies the above-described conditions is appropriately
selected so that the edge of the processed region is not exposed
with the light.
[0368] Subsequently, as shown in FIG. 30B, a second exposing light
312 is relatively scanned against the whole region to be ablated.
Before the second and subsequent scans, the distance between the
optical system and previously treated substrate is set in the image
forming position. By this setting, the region of the second or
subsequent scan can be set to be substantially narrower than that
of the first scan. This can prevent the particles from being
generated in the processed region edge.
[0369] In the processing process, the observation system 220
constituted of the CCD camera is used to count the particles
inside/outside the processed region. Moreover, the image is stored
before/after the exposure, and the difference is obtained. When the
difference is substantially 0, the processing in the portion is
stopped; otherwise, the processing is controlled to be continuously
performed.
[0370] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may also be ended with the slight
amount of the processed film remaining in the processed region.
TWELFTH EMBODIMENT
[0371] In a twelfth embodiment, a method of removing the
anti-reflection film of the lower layer or reducing the film
thickness without removing the resist film of the upper layer will
be described.
[0372] For the light source for the irradiation, a pulse laser of a
third higher harmonic wave (wavelength 355 nm) of Q-Switch Nd-YAG
laser was used. An energy density per pulse is usually 0.03
J/cm.sup.2pulse to 0.15 J/cm.sup.2pulse. This energy density per
pulse is smaller than that for ablating/removing both the resist
film and anti-reflection film. The energy density per pulse is
appropriately set such that the resist film of the upper layer is
not destroyed by the abrasion of the anti-reflection film.
[0373] FIG. 31 shows a section at exposing of the whole region to
be exposed with the size of exposure region having substantially
the same size as that of the whole region to be exposed. FIG. 31 is
a sectional view showing the manufacturing step of the
semiconductor device according to the twelfth embodiment of the
present invention. In FIG. 31, the same parts as those of FIG. 1B
are denoted with the same reference numerals and the description
thereof is omitted.
[0374] As seen from FIG. 31, without destroying the resist film
106, the anti-reflection film 105 is removed. Moreover, any
sticking particle was not observed on the resist film 106.
[0375] In the related-art removing by laser abrasion, the exposure
light is transmitted through the resist film, ablation (explosion)
occurs in the anti-reflection film, and scattered materials of the
resist film and anti-reflection film stick to the vicinity of the
removed region. On the other hand, when an irradiation amount is
reduced to 0.03 J/cm.sup.2pulse, momentary explosion does not
occur. As a result, it is considered that a gas generated from the
anti-reflection film by the exposure is exhausted from a porous
resist film.
[0376] When the region is exposed with the energy density per pulse
smaller than that for the removing by the related-art ablation,
only the anti-reflection film 105 is vaporized, and the particle
generation around the removed portion can be eliminated.
[0377] However, under the influence of an optical profile, a
removed region and incompletely removed region exist in a mixed
manner in the whole region to be exposed of the anti-reflection
film 105. This result indicates that the anti-reflection film is
gradually vaporized and removed so as not to destroy the resist
film and this is remarkably influenced by the optical profile.
[0378] To solve the problem, the exposure region of laser beam
having the slit shape is relatively scanned against the whole
region to be exposed to remove the anti-reflection film of the
processed region.
[0379] Results are shown in FIGS. 32A to 32C. FIGS. 32A to 32C are
sectional views showing the manufacturing steps of the
semiconductor device according to the twelfth embodiment of the
present invention. In FIGS. 32A to 32C, the same parts as those of
FIG. 1B are denoted with the same reference numerals and the
detailed description thereof is omitted.
[0380] A state obtained after scanning the exposure region once is
shown in FIG. 32A. Moreover, a state obtained after scanning the
exposure region twice is shown in FIG. 32B. Furthermore, a state
obtained after scanning exposure region three times is shown in
FIG. 32C.
[0381] As seen from FIG. 32C, when the number of scans of exposure
region is increased, the anti-reflection film is more uniformly
removed.
[0382] With the use of the above-described method, it is concluded
that without destroying the resist film, the anti-reflection film
can be uniformly removed.
[0383] In the present embodiment, the laser beam is used as the
exposure light, but it is also possible to emit the light having
the wavelength absorbed by the anti-reflection film, such as the
light of a KrF excimer lamp. Moreover, as the exposure method, the
method described in the first embodiment is used, but any method of
the above-described embodiments may appropriately be selected as a
method in which any particle sticks.
[0384] For the light source for the exposure in the present
embodiment, the pulse laser of the third higher harmonic wave of
Q-Switch Nd-YAG laser was used, but the present invention is not
limited to this. An absorption coefficient of the anti-reflection
film is larger than, preferably twice or more that of the resist
film formed in the upper layer. When the wavelength satisfies this
condition, a fourth higher harmonic wave (wavelength 266 nm) of the
Q-Switch Nd-YAG laser and pulse laser such as a KrF excimer laser
may also be used.
[0385] Moreover, the energy density per pulse in the present
embodiment is set to 0.03 J/cm.sup.2pulse to 0.15 J/cm.sup.2pulse,
but this is not limited. It is important to optimize parameters so
as to prevent the resist film, which is the upper-layer film, from
bumping.
[0386] Furthermore, the exposure shape is not limited to the long
slit shape, and the dot shape or the arrangement of a plurality of
the shapes may appropriately be selected.
[0387] Additionally, in the present embodiment, the energy density
per pulse irradiation amount in removing the anti-reflection film
is set to 0.03 J/cm.sup.2pulse, but the present invention is not
limited to this. Any irradiation amount may be used, as long as the
anti-reflection film can be removed to form a hollow region.
Moreover, instead of removing all the anti-reflection films, the
energy density per pulse is further reduced, and the film thickness
is thinned to such an extent that the alignment light can be
detected. Even in this case, a similar effect is obtained.
13TH EMBODIMENT
[0388] A method of selectively removing only the anti-reflection
film formed on the alignment mark will be described hereinafter
with reference to the drawings. In a 13th embodiment, the present
invention is applied, when a pattern transfer film (intermediate
film) is disposed between the resist and anti-reflection film.
Since details of the treated substrate are the same as those of the
first embodiment, they are omitted here. First a method of forming
a resist pattern on the substrate to be treated will be
described.
[0389] FIGS. 33A to 33C are sectional views showing the
manufacturing steps of the semiconductor device according to the
13th embodiment of the present invention. It is to be noted that in
FIGS. 33A to 33C, the same parts as those of FIG. 1B are denoted
with the same reference numerals and the detailed description
thereof is omitted.
[0390] First, as shown in FIG. 33A, an anti-reflection film 321
having a film thickness of 300 nm is formed on the interlayer
insulating film 101 in a rotary application method. Here, as the
anti-reflection film 321, an inorganic base material containing
fine carbon particles was used. Next, a silicon oxide film 322
which is the pattern transfer film is formed in a film thickness of
80 nm on the anti-reflection film 321 in the rotary application
method.
[0391] This substrate is transferred to the laser exposure
apparatus shown in FIG. 2. Subsequently, by the method described in
the above-described embodiment, only the anti-reflection film
including the alignment mark 102 and bar in bar mark (not shown) on
the region is removed. Details of this method will be described
hereinafter (FIG. 33B). In the present embodiment, the fourth
higher harmonic wave of the Nd-YAG laser (wavelength 266 nm) was
used as the exposure light, and the energy density per pulse was
set to 0.025 J/cm.sup.2pulse. Here, energy density per pulse was
set in the same manner as in the twelfth embodiment to obtain the
hollow state in which only the anti-reflection film is removed. In
this case, in the vicinity of the removed region, no sticking
particles were observed.
[0392] Here, when the energy density per pulse is reduced to 0.025
J/cm.sup.2pulse, different from the related-art laser ablation, no
momentary explosions occurred. It is considered that the gas
generated by the exposure is exhausted from the intermediate film
to prevent the intermediate layer from being flied/scattered.
[0393] With the exposure in the energy density per pulse which is
smaller than that of the removing by the related-art ablation, only
the anti-reflection film is evaporated, and the particle generation
around the removed portion can be eliminated.
[0394] Thereafter, as shown in FIG. 33C, a chemical amplification
type positive resist film 323 having a film thickness of 300 nm for
an ArF light (wavelength 193 nm) is formed in the rotary
application method.
[0395] Furthermore, the method comprises: transferring the
substrate to be treated to a step and repeat type reduction
projecting exposure apparatus in which the ArF excimer laser is
used as the light source; aligning the pattern to be exposed with
the substrate to be treated in an ETTR process; and thereafter
exposing the desired pattern in the substrate to be treated.
Thereafter, the method comprises: performing heating treatment
referred to as post exposure bake (PEB); and developing the image
with an alkali developing solution to form the desired resist
pattern.
[0396] When only the anti-reflection film is removed in a state
free of particles, high-precision alignment can be realized without
deteriorating the yield.
[0397] In the present embodiment, the fourth higher harmonic wave
of the Nd-YAG laser was used as the light source in removing the
anti-reflection film, but the present invention is not limited to
this. It is preferable to select the light source in accordance
with an optical constant of the film to be removed.
[0398] Moreover, in the present embodiment, the energy density per
pulse in removing the anti-reflection film is set to 0.025
J/cm.sup.2pulse, but the present invention is not limited to this.
As long as the anti-reflection film can be removed to form the
hollow region, any irradiation amount may be used. Moreover,
instead of removing all the anti-reflection films, the energy
density per pulse is further reduced, and the film thickness is
thinned to such an extent that the alignment light can be detected.
In this case also, a similar effect is obtained.
[0399] Moreover, it can be confirmed that the alignment with
respect to the bar in bar mark results in good-precision
superposition. In the related art, since the anti-reflection film
is also formed on the bar in bar mark, the precision of the check
has heretofore been bad.
14TH EMBODIMENT
[0400] In the above-described embodiment, the method of removing at
least the anti-reflection film for use in the lithography process
by the irradiation in ETTR alignment has been described.
[0401] On the other hand, in the semiconductor device, films opaque
to the exposure wavelength for use in the lithography process are
formed such as a polyimide film, Si polycrystalline film, organic
interlayer insulating film, silicon nitride film, and silicon
carbide film. When these opaque films are formed on the alignment
mark, a problem occurs that aliment mark can not be detected by the
ETTR alignment.
[0402] In the present embodiment, a method of removing these opaque
films will be described.
[0403] FIGS. 34A to 34F are sectional views showing the
manufacturing steps of the semiconductor device according to a 14th
embodiment of the present invention.
[0404] As shown in FIG. 34A, a semiconductor device 400 being
manufactured is prepared. Alignment marks 402 and element
separation insulating films 403 formed of SiO.sub.2 are formed on
an Si substrate 401. An interlayer insulating film 406 formed of an
organic material is formed on the Si substrate 401 and alignment
marks 402. Semiconductor elements 404 such as a large number of
transistors and capacitances are formed in a device pattern region
of the Si substrate 401. In this device, the interlayer insulating
film 406 formed of the organic material absorbs the exposure
wavelength. Therefore, when only the anti-reflection film is
removed, aliment mark cannot be detected by the ETTR alignment. It
is to be noted that reference numeral 405 denotes a gate insulating
film.
[0405] In the present embodiment, as shown in FIG. 34B, an
anti-reflection film 407 is formed on the interlayer insulating
film 406. Next, as shown in FIG. 34C, the anti-reflection film 407
and interlayer insulating film 406 are removed. As the irradiation
method, any method described in the above embodiments without any
sticking particle is appropriately selected.
[0406] Thereafter, as shown in FIG. 34D, the surface on the
anti-reflection film 407 is coated with a resist film 408. In a
state shown in FIG. 34D, since a film completely absorbing the
exposure light is not formed on the alignment marks 402, it is
possible to observe the alignment mark with the exposure
wavelength.
[0407] That is, it is possible to detect aliment mark by the ETTR
alignment, the alignment is performed with a high precision, and as
shown in FIG. 34E, it is possible to pattern the resist.
[0408] Subsequently, as shown in FIG. 34F, the patterned resist
film 408 is used as the mask to pattern the interlayer insulating
film 406, and a via-hole can be formed with high precision.
Thereafter, the resist film 408 and anti-reflection film 407 are
removed.
[0409] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with a slight amount of
the processed film remaining in the processed region.
15TH EMBODIMENT
[0410] The silicon nitride film or silicon carbide film are formed
on a Cu wire pattern formed on the semiconductor device in order to
inhibit Cu from being diffused into the interlayer insulating film.
These films absorb the light having the exposure wavelength. This
causes a problem that aliment mark cannot be detected by the ETTR
alignment.
[0411] FIGS. 35A to 35D are sectional views showing the
manufacturing steps of the semiconductor device according to a 15th
embodiment of the present invention.
[0412] First, as shown in FIG. 35A, a semiconductor device 500
being manufactured is prepared. A first interlayer insulating film
502 formed of SiC is formed on an Si substrate 501. In the first
interlayer insulating film 502, alignment marks 503 and Cu wires
504 are buried/formed. A silicon nitride film 505 is formed on the
alignment marks 503 and Cu wires 504. A second interlayer
insulating film 506 is formed on the silicon nitride film.
[0413] Subsequently, as shown in FIG. 35B, the second interlayer
insulating film 506 is coated with an anti-reflection film 507
formed of the organic material. Moreover, the anti-reflection film
507, second interlayer insulating film 506, and silicon nitride
film 505 are removed by the exposure of the laser beam.
[0414] Subsequently, as shown in FIG. 35C, after forming a resist
film 508, the high-precision alignment is performed by the ETTR
alignment, and resist pattern 508 is formed the pattern for wire
trenches.
[0415] Subsequently, as shown in FIG. 35D, the wire trenches are
formed in the second interlayer insulating film 506 by the RIE
process. Thereafter, the resist film 508 and anti-reflection film
507 are removed.
[0416] As described above, with the use of the optical processing
method of the present invention, in the lithography process, it is
possible to detect the alignment mark by the ETTR alignment, and it
is possible to form the pattern with high precision.
[0417] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with the slight amount of
the processed film remaining in the processed region.
16TH EMBODIMENT
[0418] Even when a photosensitive polyimide film is formed on the
semiconductor device, and the film is patterned by the lithography
process, it is possible to apply the optical processing method of
the present invention.
[0419] Particularly, photosensitive polyimide absorbs not only the
exposure wavelength but also visible light, and has a problem that
it is difficult to observe the alignment mark formed in the lower
layer. Moreover, when the mark formed in the lower layer is a
stepped pattern, non-uniformity of the film thickness of the
polyimide film on the alignment mark deteriorates the alignment
precision, and a large number of alignment defects are
generated.
[0420] FIGS. 36A to 36C are sectional views showing the
manufacturing steps of the semiconductor device according to a 16th
embodiment of the present invention.
[0421] First, as shown in FIG. 36A, a semiconductor device 600
being manufactured is prepared. In the semiconductor device 600, a
first interlayer insulating film 602 is formed on an Si substrate
601. On the first interlayer insulating film 602, alignment marks
603 and Al pad 604 are formed. On the first interlayer insulating
film 602, the alignment marks 603 and Al pad 604 are coated with a
photosensitive polyimide film 606 via a second interlayer
insulating film 605.
[0422] As shown in FIG. 36B, the photosensitive polyimide film 606
on the alignment marks 603 is removed by the optical processing
method.
[0423] Subsequently, when the alignment is performed as shown in
FIG. 36C, the mark can be observed with high precision, and
alignment defects drastically decrease. FIG. 36C shows a shape
obtained after photosensitive polyimide is patterned in the
lithography process and thereafter the insulating film on the Al
pad is processed by the RIE process.
[0424] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with a slight amount of
the processed film remaining in the processed region.
17TH EMBODIMENT
[0425] The present embodiment shows another example of the optical
shaping portion of the optical processing apparatus shown in FIG.
2.
[0426] For example, instead of the aperture mask, an optical device
(e.g., Digital Micromirror Device (registered trademark of Texas
Instruments Co., Ltd.)) may also be used in which a plurality of
micro mirrors are two-dimensionally arranged. The mirrors are very
small as compared with diameters of the laser beams, and the
directions of the respective mirrors can be changed. In the optical
device, the directions of the respective micro mirrors are
controlled, and it is thereby possible to form an optical image
which has an arbitrary size and shape. Therefore, when the
directions of the respective micro mirrors constituting this
optical device are controlled, the laser beam of the optical image
can be emitted in accordance with the size and direction of the
mark.
[0427] That is, assuming that the laser beams are transmitted
through the view field diaphragm system and slit/dot diaphragm
system,
[0428] bright portion+bright portion.fwdarw.bright portion, and
[0429] other than the above.fwdarw.dark portion, bright/dark
portion grid information on a mask surface is generated.
[0430] A grid is preferably fine. For example, in a system for
reduction to 1/20 in the projecting optical system, miniaturization
of about 5 .mu.m is achieved on the aperture mask (the micro
mirrors each having this size are two-dimensionally arranged). The
bright/dark portion grid information is imparted to the optical
device, angles of the respective micro mirrors are controlled so
that only the bright portion is exposed with the light on the
substrate, and the substrate is exposed with the laser beam.
[0431] Moreover, with the use of this optical system, while the
substrate remains stationary, the laser beam can be scanned. When
the scanning of the laser beam is assumed, the bright/dark portion
grid information is calculated for each process time, and the
information may be imparted to the optical device with respect to
the corresponding process time and controlled. In this case, only
the optical device can be used to process the film.
18TH EMBODIMENT
[0432] In an 18th embodiment, in the optical processing apparatus
shown in FIG. 2, another example of a processing unit having a
mechanism for supplying the flowing liquid to the processed region
is shown.
[0433] FIG. 37 is a diagram showing a schematic constitution of a
processing unit according to the 18th embodiment of the present
invention. It is to be noted that in FIG. 37 the same parts as
those of FIG. 2 are denoted with the same reference numerals, and
the detailed description is omitted.
[0434] In this case, a flowing liquid system does not use a
circulation system, and the solution 239 is supplied to a flow
direction change unit 703 from a solution supply unit 701 via a
solution supply pipe 702. The flow direction change unit 703 can
rotate with respect to a vertical axis of a main surface on the
substrate main surface. In one end of the flow direction change
unit 703, a solution guide pipe 704 connected to the solution
supply pipe 702 is disposed, and the solution is supplied to the
substrate 100 main surface from a spout port 705 in the tip of the
pipe. The solution 239 flows between the substrate 100 and window
236, and is discharged via a discharge port 706 disposed in a
position opposite to the spout port 705. The discharge port 706 is
broadened to such an extent that a turbulent flow is not generated
in the solution 239 supplied onto the substrate 100 from the spout
port 705. The flow direction change unit 703 is controlled to
change the directions of the spout port 705 and discharge port 706
so that the solution has the direction of the flow preset with
respect to the relative scan direction of the substrate 100 and
laser beam.
[0435] For example, the processing unit can be used in a process
of: scanning the laser beam with respect to the region to be
processed in one direction from the inside of the desired processed
region to process the region and stop the processing in one end;
and subsequently scanning the laser beam with respect to the
processed region to the other end from the inside of the processed
region to process the region. That is, when the liquid flow is
generated in a direction opposite to the relative scan direction of
the laser beam during the processing, for example, as shown in FIG.
38A, 38B, the flow may be generated. FIGS. 38A and 38B are plan
views showing a processing state using the processing unit shown in
FIG. 37. It is to be noted that in FIGS. 38A and 38B, the same
parts as the above-described parts are denoted with the same
reference numerals, and the detailed description is omitted.
[0436] As shown in FIG. 38A, when an exposure region 712 moves in a
direction to the left of a drawing sheet from the right, the spout
port 705 of the flow direction change unit 703 is disposed on the
left side of a the whole region to be exposed region 711, and the
discharge port 706 is disposed on the right side of the whole
region to be exposed to form the liquid flow. Moreover, when the
exposure region 712 moves to the right from the left of the drawing
sheet, as shown in FIG. 38B, the flow direction change unit 703 or
substrate 100 is relatively rotated by 180 degrees around the
exposure region 712, the spout port 705 of the flow direction
change unit 703 is disposed on the right side of the whole region
to be exposed 711, and the discharge port 706 is disposed on the
left side of the whole region to be exposed 711 to form the liquid
flow.
[0437] FIGS. 39A and 39B show the solution supply unit shown in
FIGS. 37, 38A and 38B disposed so that nozzle positions are
opposite to each other. In this case, the solution supply mechanism
is only translated/moved in a direction crossing at right angles to
the flowing liquid direction in the whole region to be exposed, so
that the liquid flow direction can easily be changed. When the
exposure region is relatively scanned to the left of the sheet
surface from the inside of the whole region to be exposed to
process the region, the unit is disposed as shown in FIG. 39A.
Subsequently, when the irradiation region is relatively scanned to
the right side of the sheet surface from the inside to process the
region, the unit is disposed as shown in FIG. 39B.
19TH EMBODIMENT
[0438] FIGS. 40A to 40C are sectional views showing a problem of an
alignment defect in forming Al wiring.
[0439] The sectional view shown in FIG. 40A shows a stage before
the Al wiring is formed. In an interlayer insulating film 802
formed on a semiconductor substrate 801, at least a via-hole 805 to
be connected to the Al wiring, and alignment marks 806 for
performing the alignment are formed. It is to be noted that
reference numerals 803, 804 denote a plug and lower-layer wiring
layer. It is to be noted that concave/convex portions are formed in
the surfaces of the alignment marks 806. The reason for this will
be described later.
[0440] Next, as shown in FIG. 40B, an Al film 807, anti-reflection
film 808, and resist film 809 are successively formed. Barrier
metals constituted of Ti, TiN, Ta, TaN are formed in an Al film 807
upper layer and/or Al film 807 lower layer (not shown).
[0441] In the state shown in FIG. 40B, the Al film 807 is formed on
the alignment marks 806. Therefore, the alignment marks 806 cannot
directly be detected. Therefore, without detecting the position
information of the alignment marks 806 formed in the via layer of
the Al film 807 lower layer, the concave shape of the Al film 807
surface is detected to align the films.
[0442] Then, in order to perform the alignment by the concave shape
of the Al film 807 surface, step portions are disposed in the
alignment marks 806 formed in the via layer beforehand. When the Al
film 807 is formed, concave shape are generated in the surface of
the Al film 807.
[0443] When the position information of the alignment marks 806 is
read by the concave shape of the Al film 807 surface, and
patterned, an Al wiring 810 is formed as shown in FIG. 40C.
[0444] However, since the Al film 807 surface concave shape are
asymmetric against the concave shape of the substrate because of
properties of film forming methods such as sputter deposition,
strains are generated in the position information and an alignment
error is enlarged. This alignment error induces contact defect
between the Al wiring layer 810 and via-hole 805. This causes a
problem that chip yield drops.
[0445] In order to raise the chip yield, the Al film 807 on the
alignment marks 806 is selectively removed before the alignment is
performed. In the alignment for performing lithography of the Al
wiring layer, it is necessary to take a method of directly
detecting the alignment mark formed in the substrate via layer.
[0446] FIGS. 41A to 41F are sectional views showing the
manufacturing steps of the semiconductor device according to the
19th embodiment of the present invention. It is to be noted that in
FIGS. 41A to 41F, the same parts as those of the FIGS. 40A to 40C
are denoted with the same reference numerals, and the detailed
description thereof is omitted.
[0447] First, as shown in FIG. 41A, after an Al film 811 is formed,
a resist film 812 is formed on the Al film 811. Subsequently, as
shown in FIG. 41B, the whole region to be ablated of the Al film
811 in which the alignment mark and the bar in bar mark (not shown)
are formed below is irradiated with the laser beam to selectively
remove the resist film 812 on the alignment marks. As the removing
method, any method described above in the other embodiments may
also be used.
[0448] Subsequently, as shown in FIG. 41C, a wet etching method is
used to remove the Al film 811 of the processed region. The resist
film 812 is removed by ashing. In this state, a structure is
obtained in which the Al film 811 on the alignment marks 806 and
the bar in bar mark is selectively removed.
[0449] In the state in which the Al film 811 on the alignment marks
806 is selectively removed to form a resist film for i-ray
814/anti-reflection film 813 as shown in FIG. 41D. Next, the
position information of the alignment marks 806 formed in the via
layer is used to perform alignment adjustment. Thereafter,
exposure/development is performed to form the resist pattern 814 as
shown in FIG. 41E.
[0450] When the alignment is performed with the bar in, bar mark,
it can be confirmed that superposition is achieved with good
precision. It has heretofore been difficult to check the alignment,
because the Al film is also formed on the alignment check mark.
However, the check is much facilitated.
[0451] After the above-described lithography process, as shown in
FIG. 41F, the Al film 811 is processed by the RIE process, an Al
wire 815 is formed, and the resist pattern 814 and anti-reflection
film 813 are removed. By the above-described manufacturing method,
it is possible to form Al wiring without contact defect between the
Al wiring 815 and via 805.
[0452] It is to be noted that in the present embodiment the forming
of the processed film and the laser processing can continuously be
performed by the processing apparatus. However, the forming of the
processed film and the laser processing may also be performed with
the independent apparatuses.
20TH EMBODIMENT
[0453] With an insufficient alignment precision between the
position of exposure region and the whole region to be ablated,
every time the reciprocating scan is repeated, a problem occurs
that new particles are generated from the edge of the whole region
to be ablated.
[0454] In the second embodiment, the method has been described
comprising: considering the alignment precision in the vicinity of
the edge of the whole region to be ablated; controlling the view
field setting system in the second and subsequent exposures to set
the exposure region to be smaller than that of the whole region to
be ablated middle portion; inhibiting the particles from being
generated in the vicinity of the edge of the of the whole region to
be ablated; and preventing the particles from sticking into the
processed region.
[0455] A method for a similar purpose will be described comprising:
shifting the position of the exposure region while processing the
whole region to be ablated to reduce the generation of the
particles.
[0456] FIGS. 42A to 42E are plan views showing the optical
processing method according to a 20th embodiment of the present
invention.
[0457] First, as shown in FIG. 42A, the exposure region having the
slit shape on the substrate is relatively scanned against the
substrate to ablate a first region R.sub.1. One vertex of the first
region R.sub.1 contacts one of vertices of a processed region
R.sub.0.
[0458] Subsequently, as shown in FIG. 42B, the irradiation region
of the laser beam is changed to a second region R.sub.2 from the
first region R.sub.1. One vertex of the second region R.sub.2 which
does not contact the vertex of the first region R.sub.1 contacts
one of the vertices of the processed region R.sub.0 Moreover, the
processed film in the second region R.sub.2 is ablated in the same
manner as in the first region R.sub.1.
[0459] Thereafter, as shown in FIG. 42C, the irradiation region of
the laser beam is changed to a third region R.sub.3 from the second
region R.sub.2. One vertex of the third region. R.sub.3 which does
not contact the vertices of the regions R.sub.1, R.sub.2 contacts
one of the vertices of the processed region R.sub.0. Moreover, the
processed film in a region is ablated in the same manner as in the
first region R.sub.1.
[0460] Thereafter, as shown in FIG. 42D, the irradiation region of
the laser beam is changed to a fourth region R.sub.4 from the third
region R.sub.3. One vertex of the fourth region R.sub.4 which does
not contact the vertices of the regions R.sub.1, R.sub.2, R.sub.3
contacts one of the vertices of the processed region R.sub.0.
Moreover, in the same manner as in the first region R.sub.1, the
processed film in the fourth region R.sub.4 is ablated. In the
above-described steps, the processed film in the processed region
R.sub.0 is ablated.
[0461] Moreover, the method finally comprises: repeatedly
reciprocating/scanning the laser beam having a long slit shape in a
fifth region R.sub.5 set in the processed region R.sub.0; and
removing the particles remaining in the fifth region R.sub.5 to
form the whole region to be ablated. It is to be noted that the
fifth region R.sub.5 may collectively be exposed to remove the
remaining particles and to form the whole region to be ablated.
[0462] As described above, when the position of the exposure region
is shifted to form the whole region to be ablated, the number of
exposure of the edge of the whole region to be ablated can be
reduced as much as possible. Therefore, the particles from the edge
of the whole region to be ablated can be inhibited, and it is
possible to prevent the particles from sticking into the whole
region to be ablated.
[0463] In the processing process of the fifth region R.sub.5, the
observation system 220 constituted of the CCD camera is used to
count the particles inside/outside the processed region. Moreover,
the image is stored before/after the laser irradiation, and the
difference is obtained. When the difference is substantially 0, the
processing in the portion is stopped; otherwise, the processing is
controlled to be continuously performed.
[0464] It is to be noted that a region redundantly scanned in the
scan in the regions R.sub.1 to R.sub.4 is set to the fifth region
R.sub.5 and thereby the number of scans in the fifth region R.sub.5
can be reduced.
[0465] It is to be noted that the scan region may be changed by
moving the position of the view field setting system or moving the
substrate.
[0466] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with the slight amount of
the processed film remaining in the processed region.
21ST EMBODIMENT
[0467] With an insufficient alignment precision between the
position of exposure region and the whole region to be ablated,
every time the reciprocating scan is repeated, a problem occurs
that new particles are generated from the edge of the whole region
to be ablated.
[0468] In the second embodiment, the method has been described
comprising: considering the alignment precision in the vicinity of
the edge of the whole region to be ablated; controlling the view
field setting system in the second and subsequent exposures to set
the exposure region to be smaller than that of the whole region to
be ablated middle portion; inhibiting the particles from being
generated in the vicinity of the edge of the of the whole region to
be ablated; and preventing the particles from sticking into the
processed region.
[0469] On the other hand, in the 20th embodiment, without changing
the size of the view field setting system, the position of the
exposure region is changed to process the whole region to be
ablated. In a 21st embodiment, a method of vibrating the substrate
to be treated and exposing the light to process the whole region to
be ablated for similar purpose will be described.
[0470] FIGS. 43A and 43B are sectional views showing the
manufacturing steps of the semiconductor device according to the
21st embodiment of the present invention.
[0471] First, as shown in FIG. 43A, the substrate 100 is vibrated
by piezoelectric devices in at least a horizontal direction while
scanning a thinned slit-shaped laser beam 821 to process the film
to be ablated. At this time, as shown in FIG. 44, a region R.sub.f
actually exposed is broader than a region R.sub.i exposed in a
state free of vibration. FIG. 44 is a plan view showing the
exposure region, when the substrate is vibrated. Therefore, in the
method of vibrating the substrate 100 while scanning the laser
beam, the actually processed region is broader than the region
processed in a state in which the substrate is not vibrated.
[0472] Next, the piezoelectric device driving control circuit is
disconnected. Without vibrating the substrate, as shown in FIG.
43B, a thinned slit-shaped laser beam 822 is repeatedly
reciprocated/scanned in the whole region to be ablated to remove
the particles remaining in the whole region to be ablated. It is to
be noted that the particles remaining in the processed region may
also be removed by the collective exposure.
[0473] In the present embodiment, the substrate is vibrated.
However, the substrate may also be vibrated by the piezoelectric
device disposed in the view field setting system.
[0474] In the second and subsequent scan steps, the observation
system 220 constituted of the CCD camera is used to count the
particles inside/outside the processed region. Moreover, the image
is stored before/after the exposure, and the difference is
obtained. When the difference is substantially 0, the processing in
the portion is stopped; otherwise, the processing is controlled to
be continuously performed.
[0475] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with a slight amount of
the processed film remaining in the processed region.
22ND EMBODIMENT
[0476] In the second embodiment, the method has been described
comprising: considering the alignment precision in the vicinity of
the edge of the whole region to be ablated; controlling the view
field setting system in the second and subsequent exposures to set
the exposure region to be smaller than that of the whole region to
be ablated middle portion; inhibiting the particles from being
generated in the vicinity of the edge of the of the whole region to
be ablated; and preventing the particles from sticking into the
processed region.
[0477] In a 22nd embodiment, a gap between the window 236 of the
optical processing apparatus 200 shown in FIG. 2 and the substrate
100 surface is changed in accordance with the number of scans of
the exposure region to ablate the region.
[0478] FIGS. 45A and 45B are sectional views showing the
manufacturing steps of the semiconductor device according to the
22nd embodiment of the present invention.
[0479] First, as shown in FIG. 45A, the gap between the substrate
100 surface and window 236 is controlled to set the thickness of
the solution 239 on the substrate 100 to D1. Moreover, a thinned
slit-shaped laser beam 831 is relatively scanned against the whole
region to be ablated.
[0480] Since the laser beam incident upon the pure water is
refracted, an area of the exposure region is A1.
[0481] Subsequently, as shown in FIG. 45B, the gap between the
window 236 and substrate 100 surface is changed to set the
thickness of the solution 239 on the substrate 100 to D2 (<D1).
Moreover, again with the same setting of the scan region as that of
the first scan, the long slit-shaped laser beam is repeatedly
reciprocated/scanned in whole region to be ablated.
[0482] When the solution 239 is thinned, the influence of the
refraction of the laser beam in the solution 239 is reduced.
Therefore, as shown in FIG. 46, an area A2 of the exposure region
is smaller than the area A1. Therefore, the second scan region can
be set to be smaller than the first scan region. FIG. 46 is a plan
view showing the irradiation area of one pulse of the laser
beam.
[0483] As described above, when the solution film thickness on the
treated substrate in the process is changed, the generation of the
particles from the edge of the whole region to be ablated can be
inhibited, and it is possible to prevent the particles from
sticking into the processed region.
[0484] In the second scan step, the observation system 220
constituted of the CCD camera is used to count the particles
inside/outside the processed region. Moreover, the image is stored
before/after exposure, and the difference is obtained. When the
difference is substantially 0, the processing in the portion is
stopped; otherwise, the processing is controlled to be continuously
performed.
[0485] In the present embodiment, the processed film on the
alignment mark is completely removed, but the present invention is
not limited to this. For example, when the alignment mark can be
detected by the optical system for use in the alignment
measurement, the processing may be ended with the slight amount of
the processed film remaining in the processed region.
23RD EMBODIMENT
[0486] First, a constitution of a laser processing apparatus will
be described. FIG. 47 is a diagram showing the constitution of the
laser processing apparatus according to a 23rd embodiment of the
present invention. In FIG. 47, the same parts as those of FIG. 2
are denoted with the same reference numerals, and the description
thereof is omitted.
[0487] As shown in FIG. 47, the optical processing apparatus 200
includes the laser optical system 210, observation system 220, and
laser processing section 230, and further includes a gradation/tone
classification unit 251, film structure identification unit 252,
and energy amount setting unit 253.
[0488] This laser optical system 210 includes the laser oscillator
211, laser oscillator control unit 212 which controls the laser
oscillator 211, optical system 214, half mirror 217, and condenser
lens 216.
[0489] The laser beam 213 emitted from the laser oscillator 211 is
successively transmitted through the optical system 214 which forms
a beam shape in a size of each exposure unit, optical shaping unit
215, half mirror 217, and condenser lens 216, and the processing
surface 100a of the substrate 100 disposed in the laser processing
section 230 is exposed. The observation system 220 is inserted
between the optical shaping unit 215 and condenser lens 216.
[0490] The observation system 220 includes a light source for
observation 223 which emits a light for observing the surface of
the substrate 100, half mirror 224, and CCD camera 222.
[0491] The constitution of the optical observation system will be
described hereinafter. The image information acquired by the CCD
camera 222 is sent to the gradation/tone classification unit 251.
The gradation/tone classification unit 251 first identifies the
processed region from the image. Gradation and tone (wavelength
dispersion of the gradation) in the identified the region to be
exposed are obtained. Moreover, grids (pixels) which have
substantially the same gradation or tone are divided into groups.
Here, the grouping of the gradations or tones of the images is
similar to the obtaining of intensity distribution of a reflected
light from the substrate.
[0492] Gradation/tone information of each grid or group is sent to
the film structure identification unit 252. The film structure
identification unit 252 includes a correspondence table of the
tones/gradations and film structures obtained beforehand. The film
structure identification unit 252 compares the tone/gradation
information of each grid or group with the correspondence table.
The film structure identification unit 252 allocates the film
structure to each group based on the correspondence table. The film
structure information includes at least information of the
thickness of the film and complex refractive index. Furthermore,
data of a damage generation lower limit energy amount is also
sometimes included.
[0493] The energy amount setting unit 253 determines the energy
amount of each exposure region (processing unit) for each exposure
unit based on the film structure information.
[0494] The laser oscillator control unit 212 controls power
supplied to the laser oscillator 211 based on energy amount
information and exposure position information.
[0495] It is to be noted that the exposure position of the laser
beam is detected based on the information from the sensor 235 and
rotation control mechanism 234. It is to be noted that the exposure
position of the laser beam may also be detected based on the image
information acquired by the CCD camera 222.
[0496] Moreover, the laser beam source is used in the light source
for the processing in the present apparatus, but the present
invention is not limited to this. When the wavelength is absorbed
by the processed film, the desired processing is performed, that
is, the film thickness is reduced, or the film can be removed, any
light may also be used. For example, when the light is absorbed in
the visible or ultraviolet region in the organic or inorganic film,
the light is collected by the tungsten lamp and used. In this case,
the film thickness reduction has been confirmed. Moreover, charged
particle beams may also be used, such as an electron beam and ion
beam.
[0497] The invention concerning the present apparatus relates to
the processing in water, but is not limited to this. When the
substrate to be treated is treated in the atmosphere, the
processing is possible in an apparatus constitution shown in FIG.
48. In FIG. 48, the same mechanism is denoted with the same
reference numerals. Even in the treatment in a pressurized or
reduced pressure state, the apparatus or stage portion having a
mode of FIG. 48 is disposed in a chamber and used, and an object of
the present invention can thereby be achieved.
24TH EMBODIMENT
[0498] In a 24th embodiment, an example of the processing using the
apparatus described in the 23rd embodiment will be described.
[0499] On a wafer having a diameter of 300 mm in a semiconductor
forming process, an anti-reflection film layer having a film
thickness of 56 nm (complex refractive index=n.sub.12-k.sub.12i: i
is an imaginary number unit), and a uniform resist film having a
film thickness of 400 nm (complex refractive
index=n.sub.11-k.sub.11i: i is the imaginary number unit) are
successively formed. The laser processing apparatus shown in FIG.
47 is used to process the wafer.
[0500] First, the light intensity from the observation light source
and detection sensitivity of the CCD camera are corrected. The
correction comprises: irradiating a standard sample whose surface
(not shown) has been polished in a mirror surface form with the
light from the observation light source; receiving the reflected
light by the CCD camera; and adjusting light amount of the
observation light source or gain of the CCD camera so that the
detected gradation of the CCD camera indicates a value designated
beforehand.
[0501] After the observation system is corrected, the wafer 100 is
laid on the stage 232 in the holder 231. The solution flow unit 237
supplies a ultrapure water onto the upper surface of the wafer 100.
In a stage of the holder 231 completely filled with the ultrapure
water, the CCD camera 222 acquires the image around the whole
region to be exposed. In the present embodiment, the whole region
to be exposed is an alignment mark region. The used CCD camera 222
can acquire images of 256 gradations of white/black. The image
observed by the CCD camera 222 is sent to the gradation/tone
classification unit 251.
[0502] FIG. 49 schematically shows the image observed by the CCD
camera 222 (set to a gray scale). The gradation/tone classification
unit 251 evaluates the gradation from the image. In the present
embodiment, there are 167 gradations in a second region 1302 in
which the alignment marks are formed. Moreover, a first region 1301
includes 56 gradations. It is to be noted that in FIG. 49,
reference numeral 1300 denotes a processed region.
[0503] This gradation information is next sent to the film
structure identification unit 252. Here, transferred data
arrangement is, for example, (x-direction exposure origin,
y-direction exposure origin, x-direction exposure width,
y-direction exposure width, gradation). This data is data in which
a plurality of gradations are grouped based on the gradation
information owned by each grid (pixel). It is to be noted that the
x-direction and y-direction exposure widths are exposure units
(processing units) predetermined by the apparatus and indicate
fixed values. The exposure unit has a shape of a slit or dot with
respect to the processed region.
[0504] It is to be noted that the slit shape mentioned herein is a
shape in which the longitudinal direction of the exposure shape is
substantially equal to one side of the processed region and a width
of a direction crossing at right angles to the longitudinal
direction is shorter than the other side of the processed region.
Moreover, the exposure shape of the dot shape indicates that each
of two widths of the direction crossing at right angles in the
exposure shape is shorter than the width of the direction crossing
at right angles in the processed region.
[0505] Film structure search means uses the correspondence table
described, for example, in Table 1 to determine the film structure.
TABLE-US-00001 TABLE 1 Film Film Film structure structure structure
1A 1B 1C . . . Gradation 54 .+-. 3 168 .+-. 2 144 .+-. 5 Energy
upper 0.6 0.4 0.6 limit [J/cm.sup.2/shot] Energy lower 0.3 0.2 0.3
limit [J/cm.sup.2/shot] Uppermost 3 3 4 layer of substrate Number
of 4 6 5 layers Layer 1 n.sub.11, k.sub.11 n.sub.11, k.sub.11
n.sub.11, k.sub.11 Layer 2 n.sub.12, k.sub.12 n.sub.12, k.sub.12
n.sub.13, k.sub.13 Layer 3 n.sub.15, k.sub.15 n.sub.18, k.sub.18
n.sub.14, k.sub.14 Layer 4 n.sub.16, k.sub.16 n.sub.19, k.sub.19
n.sub.15, k.sub.15 Layer 5 -- n.sub.110, n.sub.16, k.sub.16
k.sub.110 Layer 6 -- n.sub.16, k.sub.16 -- Layer 7 -- -- --
[0506] In Table 1, for example, a film structure 1A is a four-layer
structure. As shown in FIG. 50A, the film structure 1A is
constituted of a resist film (layer 1) 1401, anti-reflection film
(layer 2) 1402, and substrate layers 1405 (layer 3), 1406 (layer
4). It is to be noted that only the complex refractive index is
described in the correspondence table, but in actuality, the
information of the film thickness is also attached.
[0507] As shown in FIG. 50B, a film structure 1B is constituted of
the resist film 1401 (layer 1) including a three-layer structure,
anti-reflection film 1402 (layer 2), and substrate layers 1408
(layer 3), 1409 (layer 4), 1410 (layer 5), and 1406 (layer 6). In
the film structure 1B, the uppermost layer of the substrate layer
is 1408 (layer 3). As shown in FIG. 50C, a film structure 1C is
constituted of the resist films including the three-layer structure
1401 (layer 1), 1403 (layer 2), 1404 (layer 3), and substrate
layers 1405 (layer 4), 1406 (layer 5). The uppermost layer of the
substrate layer is the substrate layer 1405.
[0508] Based on this information, the first region 1301 is
identified as the film structure 1B, and the second region 1302 is
identified as the film structure 1A. Moreover, it is seen from this
correspondence table that a maximum value of energy exposure with
respect to the first region 1301 is 0.4 J/cm.sup.2/shot, and the
maximum value of the energy exposure with respect to the second
region 1302 is 0.6 J/cm.sup.2/shot. In Table 1, an energy lower
limit is an energy necessary for removing the film. The energy
lower limit of the film structure 1A is larger than that of the
film structure 1B, because little light is absorbed in the
processed film substrate in the film structure 1A and heat value is
little in the substrate.
[0509] Moreover, the energy amount setting unit 253 sets an optimum
exposure energy amount for each exposure region (processing unit)
from the energy upper limit and lower limit and optical constant of
the film described in Table 1. When the energy is amplified by
multiple interference, an energy amount smaller than the value of
the table is assigned. Conversely, when the energy is offset, the
energy larger than the value of the table is assigned. The lower
limit of the energy amount is an energy amount with which it is
difficult to process the film to be processed. Of course, a larger
energy amount is assigned.
[0510] The energy amount setting unit 253 considers the dispersion
of the exposure energy, and sets the exposure energy amount onto
the first region 1301 to 0.3 J/cm.sup.2/shot as shown in FIG. 51.
The energy amount setting unit 253 sets the exposure energy amount
onto the second region 1302 to 0.5 J/cm.sup.2/shot. In accordance
with the energy amount set in this manner, the abrasion is
performed for each processing unit. According to the processing
method described in the present embodiment, as shown in FIG. 53,
the first and second regions 1301 and 1302 can be processed with
appropriate energies.
[0511] For example, it is assumed that the energy of the laser is
set to 0.35 J/cm.sup.2/shot regardless of the first and second
regions. In this case, the exposure energy has bad stability. When
the exposure energy is reduced, the film remains in the second
region 1302. When the exposure energy increases, the first region
1301 is damaged, and many processing defects are generated (FIGS.
54 and 55).
[0512] When the exposure energy is changed by the constitution of
the substrate to perform the ablation as in the processing method
described in the present embodiment, the processing can be realized
in a satisfactory state without any remaining film or any
damage.
[0513] When the alignment mark is exposed by this processing, the
alignment can be strictly performed. Therefore, a gate dimension
can further be reduced, and it is possible to manufacture an LSI in
which high-rate treatment is possible. In the semiconductor device
prepared using the present technique in this manner, the treatment
can be performed at a high rate. Moreover, since an allowance of
alignment can be set to be small, a chip area can also be
reduced.
[0514] In the present embodiment, the CCD camera with the gray
scale is used as the optical observation system, but the present
invention is not limited to this, and a color video camera may also
be used.
[0515] Moreover, the correspondence table is not limited to the
type of Table 1, and any mode may be used as long as the
information necessary for the processing is stored.
25TH EMBODIMENT
[0516] On the wafer having a diameter of 300 mm in the forming
process of the semiconductor device, the anti-reflection film layer
having a film thickness of 300 nm (complex refractive
index=n.sub.24-k.sub.24i: i is the imaginary number unit), SOG
layer having a film thickness of 90 nm (complex refractive
index=n.sub.23-k.sub.23i: i is the imaginary number unit), and the
uniform resist film having a film thickness of 400 nm (complex
refractive index=n.sub.21-k.sub.21i: i is the imaginary number
unit) are successively formed.
[0517] The wafer 100 is laid on the stage 232. The CCD camera 222
(RGB) acquires the image around the processed region. In the
present embodiment, the processed region is the alignment mark
region. The used CCD camera 222 can acquire images of 256
gradations of each of RGB. The image observed by the CCD camera 222
is sent to the gradation/tone classification unit 251 to evaluate
the gradation.
[0518] FIG. 56 shows a photographed image. The gradation/tone
information is assigned to the regions divided by the grids in FIG.
54. A region in a dotted line is a processed region 1500. The
gradation/tone in a second region (mark portion) 1502 is (R, G,
B)=(150, 93, 201). Moreover, the gradation/tone in a first region
1501 is (R, G, B)=(32, 100, 87). This information is next sent to
the film structure search means. Here, the transferred data
arrangement is, for example, (x-direction exposure origin,
y-direction exposure origin, x-direction exposure width,
y-direction exposure width, R gradation, G gradation, B gradation).
The data is data in which the gradations are grouped based on the
gradation information owned by each region. For the x-direction and
y-direction exposure widths, the (R, G, B) gradations of the
regions disposed adjacent to each other are compared with each
other, the regions having a gradation difference of .+-.5 or less
are regarded as the same group and grouped, and further the region
is divided into slit or dot shapes to obtain the exposure widths of
the x, y directions of the slit or dot. The film structure search
means uses the correspondence table for example, Table 2, to
determine the film structure. TABLE-US-00002 TABLE 2 Film Film Film
structure structure structure 2A 2B 2C . . . Gradation (50, 90,
122) (147, 95, 199) (30, 100, 90) (R, G, B) .+-.10% Energy upper
0.6 0.4 0.7 limit [J/cm.sup.2/shot] Energy lower 0.3 0.2 0.4 limit
[J/cm.sup.2/shot] Uppermost 3 4 4 layer of substrate Number of 4 7
5 layers Layer 1 n.sub.21, k.sub.21 n.sub.21, k.sub.21 n.sub.21,
k.sub.21 Layer 2 n.sub.22, k.sub.12 n.sub.23, k.sub.23 n.sub.23,
k.sub.23 Layer 3 n.sub.25, k.sub.25 n.sub.24, k.sub.24 n.sub.24,
k.sub.24 Layer 4 n.sub.26, k.sub.26 n.sub.28, k.sub.28 n.sub.25,
k.sub.25 Layer 5 -- n.sub.29, k.sub.29 n.sub.26, k.sub.26 Layer 6
-- n.sub.210, k.sub.210 -- Layer 7 -- n.sub.26, k.sub.26 --
[0519] In Table 2, for example, a film structure 2A is a four-layer
structure. As shown in FIG. 57A, the film structure 2A is
constituted of a resist film 1601 (layer 1) including the
three-layer structure, anti-reflection film 1602 (layer 2), and
substrate layers 1605 (layer 3), 1606 (layer 4). It is to be noted
that only the complex refractive index is described in the
correspondence table, but in actual fact the information of the
film thickness is also attached.
[0520] As shown in FIG. 57B, a film structure 2B is constituted of
the resist film 1601 including the three-layer structure (layer 1),
SOG film 1603 (layer 2), anti-reflection film 1604 (layer 3), and
substrate layers 1608 (layer 4), 1609 (layer 5), 1610 (layer 6),
and 1606 (layer 7). As shown in FIG. 57C, a film structure 2C is
constituted of the resist film 1601 (layer 1), SOG film 1603 (layer
2), anti-reflection film 1604 (layer 3), and substrate layers 1605
(layer 4), 1606 (layer 5).
[0521] Based on this information, the first region 1501 is
determined as the film structure 2B, and the second region 1502 is
determined as the film structure 2C. Moreover, it is seen from
Table 2 that the upper limit value of the exposure energy amount
with respect to the first region 1501 is 0.4 J/cm.sup.2/shot, and
the maximum value of the energy exposure with respect to the second
region 1502 is 0.7 J/cm.sup.2/shot. Here, the upper limit value of
the exposure energy amount is registered as an energy for
vaporizing only the anti-reflection film in the film structures 2B,
2C. The lower limit value of the exposure energy amount is an
energy necessary for removing the processed film. The lower limit
value of the exposure energy amount of the film structure 2C is
larger than that of the film structure 2B. This is because in the
film structure 2C the light absorption in the processed film
substrate is little and the heat value in the substrate is
small.
[0522] The energy amount setting unit 253 first sets the exposure
region (processing unit) based on the groups classified in
accordance with the gradation/tone. When the size of the region of
the group is larger than that of the exposure region, the region of
the group is divided into the slit-shaped or dot-shaped regions
smaller than the exposure regions. For example, as shown in FIG.
58, as the exposure regions in the processed region 150b, first
exposure regions 1511a to 1511g, and second exposure regions 1512a
to 1512d are set.
[0523] Moreover, the energy amount setting unit 253 sets the
optimum exposure energy amount for each exposure region (processing
unit) from the energy upper and lower limits and optical constant
of the film described in Table 2. When the energy is amplified by
the multiple interference, the energy amount smaller than the value
of the table is assigned. Conversely, when the energy is offset,
the energy amount larger than the value of the table is assigned.
The lower limit of the energy amount is the energy amount with
which it is difficult to process the film to be processed.
Naturally, the larger energy amount is assigned.
[0524] The energy amount setting unit 253 sets the energy amount of
the first exposure regions 1511a to 1511g to 0.3 J/cm.sup.2/shot.
The energy amount setting unit 253 sets the energy amount of the
second exposure regions 1512a to 1512d to 0.5 J/cm.sup.2/shot. In
accordance with the energy amount set in this manner, the ablation
is performed for each processing unit. According to the processing
method described in the present embodiment, the first and second
regions 1501 and 1502 can be processed with the respective
appropriate energies.
[0525] The exposure energy amounts into the first and second
regions 1501 and 1502 are set to be appropriate. The energy amount
is set for each exposure (processing) unit in the energy setting
means. The energy amount is optimized and determined from the
energy upper and lower limits described in the correspondence table
and the optical constant of the film. When the energy is amplified
by the multiple interference, the energy amount smaller than the
value of the table is assigned. Conversely, when the energy is
offset, the energy amount larger than the value of the table is
assigned. The lower limit of the energy amount is the energy amount
with which it is difficult to process the film to be processed.
Naturally, the larger energy amount is assigned.
[0526] A result of the assignment of the energy amount by the
above-described steps is shown in FIG. 58. To the first and second
regions, respectively, 0.3 J/cm.sup.2/shot and 0.6 J/cm.sup.2/shot
were assigned. In accordance with the energy amounts determined in
this manner, the abrasion is performed for each processing unit,
and the processing can be performed without any remaining film or
without any substrate damage.
[0527] It is assumed that the energy amount of the laser is set to
0.4 J/cm.sup.2/shot regardless of the region to perform the
processing. This energy amount is the upper limit of the first
region 1501, and is also the lower limit of the second region 1502.
Therefore, the first region 1501 was much damaged. Moreover, there
were many remaining films in the second region 1502. Therefore, it
is difficult to practically use the energy amount.
[0528] When the exposure energy is changed by the constitution of
the substrate to perform the abrasion as in the processing method
described in the present embodiment, the processing can be realized
in the satisfactory state without any remaining film or any
damage.
[0529] When the alignment mark is exposed by this processing, the
alignment can be strictly performed. Therefore, the gate dimension
can be further reduced, and it is possible to manufacture an LSI in
which a high-rate treatment is possible. In the semiconductor
device prepared using the present technique in this manner, the
treatment can be performed at the high rate. Moreover, since the
allowance of alignment can be set to be small, the chip area can
also be reduced.
[0530] In the present embodiment, a CCD camera is used as the
optical observation system, but the present invention is not
limited to this, and a video camera may also be used. Moreover, the
correspondence table is not limited to the format of Table 2, and
any mode may also be used as long as the information necessary for
the processing is stored. Moreover, in the same manner as in the
24th embodiment, the solution may be passed through the region to
be processed so as to process the region.
26TH EMBODIMENT
[0531] The constitution of the laser processing apparatus will be
described. In FIG. 59, the same parts as those of FIG. 47 are
denoted with the same reference numerals, and the detailed
description is omitted.
[0532] In FIG. 59, the gas member diameter measurement unit 1261
calculates the number of pixels in a specific gradation range in
the reflected light received by the CCD camera 222 to obtain the
measurement of the diameter of the bubble. Moreover, the laser
oscillator control unit 212 compares the measured diameter of the
bubble with the set value registered beforehand. When the diameter
of the bubble is not less than the set value, the laser oscillator
control unit 212 stops the exposure with the laser beam from the
laser oscillator 211. When the diameter of the bubble is smaller
than the set value, the laser oscillator control unit 212 allows
the laser oscillator 211 to oscillate the laser beam.
[0533] Moreover, the method of measuring the diameter of the bubble
from the image of the reflected light received by the CCD camera
222 is used, but the present invention is not limited to this. For
example, any method may be used, as long as the presence of the
bubble generated in processing the film to be processed can be
observed. For example, by a method of exposing the region with
light different from that of the light source for the processing;
and measuring a scattered angle of the light for observation by the
bubble, the presence/absence of the gas member or the size of the
gas member can be judged.
[0534] A solution flow generation unit 1263 is disposed. The
solution flow generation unit 1263 generates a solution flow in the
exposure region of the laser beam. The gas member generated by the
exposure of the laser beam can continuously be removed by the
solution flow. The solution flow generation unit 1263 preferably
generates the solution flow having a constant flow rate in a given
direction so as to prevent irregular disturbance from being
generated in the laser beam. Moreover, the solution flow generation
unit 1263 may be driven, when the laser processing is actually
performed.
[0535] Moreover, the laser beam source is used in the light source
for the processing in the present apparatus, but the present
invention is not limited to this. Any light may be used, as long as
the wavelength is absorbed by the processed film and desired
processing can be performed, that is, the film thickness can be
reduced, or the film can be removed. For example, a tungsten lamp
or Xe flash lamp can be used. When the wavelength is absorbed by
the visible or ultraviolet region in the organic or inorganic film,
the light of a tungsten or Xe flash lamp is condensed and used, and
the film thickness decreases. Furthermore, a irradiation light,
charged particle beams, such as electron or ion beams, may also be
used.
[0536] The constitution of the laser processing apparatus in an
atmosphere will be described with reference to FIG. 60. FIG. 60 is
a diagram showing the schematic constitution of the laser
processing apparatus according to the 26th embodiment of the
present invention. In FIG. 60, the same parts as those of FIG. 59
are denoted with the same reference numerals, and the description
thereof is omitted.
[0537] In FIG. 60, an air current generation unit 1262 is disposed.
The air current generation unit 1262 generates an air current in
the exposure region of the laser beam. The gas member generated by
the exposure of the laser beam can continuously be removed by the
air current. The air current generation unit 1262 preferably
generates the air current in a constant velocity in the given
direction so as to prevent irregular disturbances from being
generated in the laser beam. Moreover, the air current generation
unit 1262 may be driven, when the laser processing is actually
performed.
[0538] The exhaust port of an air current supply tube 1262a is
disposed very close to the processing surface 100a of the substrate
to be treated 100, and the air current is preferably selectively
generated only in the vicinity of the irradiation region of the
laser beam. Moreover, the gas is exhausted to generate the air
current, but may also be sucked to generate the current.
[0539] Additionally, the present apparatus relates to the
processing in atmosphere, but this is not limited. The method can
also be applied to the treatment in pressurizing treatment, or
reduced pressure treatment of the substrate to be treated, used
with a holder structure can be used in accordance with the
respective treatments.
27TH EMBODIMENT
[0540] In a 27th embodiment, the optical processing apparatus
including the apparatus constitution described in the 26th
embodiment is used. An example of application to various types of
processing required in the manufacturing steps of the semiconductor
device will be described. The application example described
hereinafter can satisfactorily be achieved using the optical
processing apparatus of the 26th embodiment.
[0541] First, a case in which the bubble above the exposure region
is not considered and the laser beam is emitted to perform the
optical processing will be described with reference to FIGS. 61A to
61C.
[0542] As shown in FIG. 61A, a substrate is prepared, and an
insulating film 1702 and resist film 1703 having a film thickness
of 1 .mu.m are formed on a silicon wafer 1701. Subsequently, the
resist film 1703 in the whole region to be ablated is exposed with
the third higher harmonic wave (wavelength 355 nm) of the Q-Switch
YAG laser, and removed. The energy density per pulse of the laser
beam is 0.4 J/cm.sup.2/shot. For example, an oscillation frequency
of a laser beam 1704 is set to 250 Hz. A size of the whole region
to be ablated is longitudinal 100 .mu.m.times.lateral 200
.mu.m.
[0543] When the resist film is exposed withthe laser beam, the film
is ablated to generate the bubble. With the presence of the bubble
in the optical path, when the next laser beam 1704 is emitted, as
shown in FIG. 61B, the laser beam 1704 is scattered by a bubble
1705 remaining above the exposure region. As a result, the outside
of the whole region to be ablated is also exposed with the laser
beam 1704.
[0544] As a result, as shown in FIG. 61C, a large number of
pinholes 1706 and particles 1707 are generated by the light scatted
outside the processed region. Additionally, film peels 1708 of the
resist film are seen in the edge portion of the whole region to be
ablated. This film peel remarkably appears also in a compound
resist film formed in a multilayered structure including a photo
resist, inorganic film, and anti-reflection film.
[0545] Then, in the process in the present embodiment, the laser
beam processing apparatus shown in FIG. 59 is used to observe the
film. The gas member diameter measurement unit 1261 measures the
size of the bubble generated from the exposure region from the
image observed by the CCD camera 222. The laser oscillator control
unit 212 controls the oscillation of the laser beam in accordance
with the measured size.
[0546] The optical processing method of the present embodiment will
be described with reference to FIGS. 62A and 62B. FIGS. 62A and 62B
are diagrams showing the optical processing method according to the
27th embodiment of the present invention.
[0547] As shown in FIG. 62A, while the bubble 1705 generated in the
previous exposure exists above the exposure region of the laser
beam in the image obtained from the CCD camera 222, the next
exposure is not performed. The gas member diameter measurement unit
1261 confirms that the bubble 1705 is carried by the solution flow
and disappears. Thereafter, as shown in FIG. 62B, the exposure with
the laser beam 1704 is resumed. While the above-described steps are
repeated, the control is executed so as to process the whole region
to be ablated.
[0548] A relation between the distance from the edge of the whole
region to be ablated and the number of pinholes is shown in FIG. 63
in the ablating without considering the existence of the bubbles
above the exposure region or in consideration of that. In FIG. 63,
A shows the number of pinholes in the ablation considering the
existence of the bubbles, and B shows the number of pinholes in the
processing without considering the existence of the bubbles. As
shown in FIG. 63, when the bubble is considered, the number of
pinholes outside the whole region to be ablated remarkably
decreases. As a result, the ablation can be performed without
influencing a position where a device pattern is to be disposed.
Moreover, the peels of the resist film can also be reduced.
[0549] Furthermore, even in the result of SEM observation, the
pinholes and particles outside the whole region to be ablated are
not found, and it has been confirmed that the peels of the resist
film in the whole region to be ablated edge portion can be
reduced.
[0550] Moreover, as shown in FIGS. 64A and 64B, the exposure region
of the laser beam preferably has the thinned slit shape against the
whole region to be ablated. FIG. 64A is a sectional view, and FIG.
64B is a plan view. As shown in FIGS. 64A and 64B, the shape of an
exposure region 1712a of a laser beam 1712 is set to the slit shape
(longitudinal 100 .mu.m.times.lateral 5 .mu.m). Moreover, the laser
beam 1712 is relatively scanned against the substrate 1701. A
method of relatively scanning the substrate 1701 against exposure
region of laser beam 1712 comprises: fixing the light axis of the
laser beam; and moving the substrate. Alternatively, the method
comprises: translating/moving the slit disposed in the optical path
of the laser beam to control the shape; and scanning the laser
beam.
[0551] As shown in FIGS. 65A and 65B, an exposure region 1711a
substantially equal in size to the whole region to be ablated 1710
is exposed with a laser beam 1711 to collectively optically process
the whole region to be ablated 1710. In this case, depending on the
type or film thickness of the resist, at a first exposure time, the
resist film 1703 is peeled in the edge portion of whole region to
be ablated 1710, and there is a fear of defect. This is because the
resist film 1703 is ablated by the exposure of the laser beam, then
a stress generated in an interface between the resist and substrate
is enlarged, and the resist film is flied and processed.
[0552] Therefore, the method preferably comprises: relatively
scanning the thinned slit-shaped light against the substrate; and
confirming that the bubble does not exist above the exposure region
to perform the predetermined processing. Thereby, since the area
processed by one exposure is small, the stress in the interface
between the resist and substrate can be relaxed, and the film peels
can be reduced.
[0553] Moreover, as shown in FIG. 66A, a plurality of slit-shaped
exposure regions 1721 may also be relatively scanned against the
whole region to be ablated 1720. Furthermore, as shown in FIG. 66B,
a plurality of slit-shaped exposure regions 1722 may also be
relatively scanned against the whole region to be ablated 1720.
Additionally, one dot-shaped exposure region may also be
scanned.
[0554] In the present embodiment, the third higher harmonic wave of
the Q-Switch YAG laser is used as the light source for the
processing, but the light source is not limited to this, and the
fourth higher harmonic wave (wavelength 266 nm) of the Q-Switch YAG
laser, pulse laser such as the KrF excimer laser, and lamp light
may also be used. Moreover, the energy density per shot is usually
0.2 J/cm.sup.2/shot to 0.5 J/cm.sup.2/shot, and the energy density
per shot whose range can satisfactorily be processed without
damaging the region inside/outside the whole region to be ablated
is appropriately adjusted. For the material other than the organic
material, the energy density per shot may appropriately be selected
without damaging the inside/outside of the whole region to be
ablated.
[0555] Moreover, the image from the CCD camera is acquired and used
as observation means of the bubble, but the observation means of
the bubble is not limited to this, and the bubble may also be
detected from the scatted light by the bubble or another light
incident upon the exposure region.
[0556] Next, in a state in which the bubble having the constant
diameter remains above the exposure region. FIG. 67 is a diagram
showing a relation between the diameter of the bubble and the
number of pinholes. As shown in FIG. 67, when the diameter of the
bubble is 3 .mu.m or less, the number of generated pinholes is
substantially 0. Therefore, with the diameter of the bubble of 3
.mu.m or less, the laser beam is exposed to ablate the whole region
to be ablated before the bubble disappears. The throughput can be
enhanced.
[0557] Moreover, as the result of the SEM observation, when the
diameter of the generated bubble is 3 .mu.m or less even, the
particles is not seen, and the peels of the resist film in the edge
portion the whole region to be ablated has been confirmed to be
reduced.
[0558] As described above, for the resist film, when the bubble
remaining above the exposure region has a diameter of 3 .mu.m or
less, the desired processing can be realized without any processing
defect such as pinholes. However, the size relation between the
pinhole and bubble differs with each type of film to be processed.
Therefore, the processing may appropriately be performed so as to
satisfy a condition that any pinhole is not generated for each
processed film in the relation between the pinhole and bubble
diameter.
[0559] Moreover, when the bubble diameter can be estimated
beforehand, the flow rate of the solution flow may be optimized.
FIG. 68 is a diagram showing a relation between a width W of the
exposure region and a bubble diameter .phi. generated at the
ablation. It is to be noted that the energy density per shot of the
laser beam is in a range of 0.2 J/cm.sup.2/shot to 0.5
J/cm.sup.2/shot. The width W of the exposure region indicates the
length of the direction in which the solution of the irradiated
region flows. As shown in FIG. 68, a curve is represented by the
upper limit value of the bubble diameter generated with respect to
the irradiation region width W. As a result, at the processing time
with an oscillation frequency Z (1/sec) and irradiation region
width W, a flow velocity V (.mu.m/sec) in the treated substrate
upper part .phi./2 (.mu.m) is set so as to satisfy the following
relation equation. Thereby, the laser beam can be oscillated
substantially in the state free of bubbles. V .gtoreq. 6 .times. W
2 .times. Z ##EQU5##
[0560] When the processing is performed so as to satisfy this
relation, the irradiation timing of the laser beam does not have to
be controlled in accordance with the size or presence/absence of
the bubble. A control unit for controlling any one of the
oscillation frequency Z, width W, and flow velocity V so as to
satisfy this relation may be disposed. The control unit may also
control the flow velocity V in accordance with the preset
oscillation frequency Z and width W. or, the control unit may also
control the oscillation frequency Z in accordance with the preset
flow velocity V and width W.
[0561] The optical processing performed while generating the air
current in the processed region by the laser processing apparatus
as shown in FIG. 60 will be described with reference to FIGS. 69A
and 69B. As shown in FIG. 69A, in the processing process, the gas
member diameter measurement unit 1261 is used to observe a gas
member 1731 generated in the air current at the exposure.
Subsequently, as shown in FIG. 69B, after confirming that the gas
member 1731 disappears above the exposure region, the exposure of
the laser beam 1704 is resumed. When the above-described steps are
repeated, the satisfactory processing can be achieved. Moreover,
also in the processing in an atmosphere, in the same manner as in
the optical processing in the solution, the method of relatively
scanning the thinned slit-shaped exposure region of the light
against the substrate may be used. Furthermore, for the shape of
the exposure region, the dot shape, or the arrangement of a
plurality of slit or dot shapes may also be used.
[0562] In the above-described embodiments, the method of removing
the resist film for use in the lithography process by the
irradiation has been described. On the other hand, in the
semiconductor device, the films such as the polyimide film, Si
polycrystalline film, and silicon carbide film are formed, and the
method can also be used in removing these films.
28TH EMBODIMENT
[0563] FIGS. 70A and 70B are diagrams showing the manufacturing
steps of the semiconductor device according to a 28th embodiment of
the present invention. FIGS. 70A and 70B show steps of
laser-processing a silicon nitride film 1742 formed on the
interlayer insulating film 1741 in the solution. The silicon
nitride film 1742 is formed, for example, using CVD or sputtering.
The silicon nitride film has a film thickness of 20 nm. The whole
region to be ablated of the silicon nitride film (longitudinal 100
.mu.m.times.lateral 200 .mu.m) is ablated with the fourth higher
harmonic wave (wavelength 266 nm) of the Q-Switch YAG laser at an
energy density per shot of 0.5 J/cm.sup.2/shot.
[0564] In the present embodiment, the apparatus shown in FIG. 50 is
used to perform the optical processing in the solution. From the
image obtained by the CCD camera 222, the gas member diameter
measurement unit 1261 measures the diameter of the bubble generated
from the exposure region by the exposure of the laser beam. As
shown in FIG. 70A, while the bubble 1705 exists above the exposure
region, the next exposure of the laser beam is not performed. As
shown in FIG. 70B, the bubble 1705 is carried by the solution flow,
the gas member diameter measurement unit 1261 confirms that the
bubble 1705 disappears, and the exposure of the laser beam 1704 is
resumed. The above-described steps are repeated, the processing is
performed.
[0565] As a result of the SEM observation after the processing, the
pinholes or scattered silicon nitride particles were not seen in
the surface of the silicon nitride film 1742, and the film peels in
the edge portion was not observed.
[0566] It is to be noted that the silicon nitride film does not
absorb the laser beam of the third higher harmonic wave (wavelength
355 nm), second higher harmonic wave (wavelength 532 nm), or basic
wave (wavelength 1064 nm) of the Q-Switch YAG laser. Therefore,
these wavelengths cannot be used to process the film.
[0567] Moreover, the processing method is not limited to this, and
may also be performed in an atmosphere.
29TH EMBODIMENT
[0568] FIGS. 71A and 71B are diagrams showing the manufacturing
steps of the semiconductor device according to a 29th embodiment of
the present invention. FIGS. 71A and 71B show the steps of
laser-processing a polyimide film 1752 formed on the silicon wafer
1701 vian an interlayer insulating film 1751 in the solution. The
polyimide film 1752 absorbs the laser beam having a wavelength of
266 nm, and is therefore processed using the fourth higher harmonic
wave (wavelength 266 nm) of the Q-Switch YAG laser at an energy
density per shot of 0.5 J/cm.sup.2/shot.
[0569] In the present embodiment, the apparatus shown in FIG. 59 is
used to perform the optical processing in the solution. From the
image obtained by the CCD camera 222, the gas member diameter
measurement unit 1261 measures the diameter of the bubble generated
from the exposure region by the exposure of the laser beam. As
shown in FIG. 71A, while the bubble 1705 exists above the exposure
region, the next exposure of the laser beam is not performed. As
shown in FIG. 71B, the bubble 1705 is carried by the solution flow,
the gas member diameter measurement unit 1261 confirms that the
bubble 1705, and the exposure of the laser beam 1704 is resumed.
The above-described steps are repeated, the processing is
performed.
[0570] As a result of the SEM observation after the processing, the
pinholes or scattered polyimide particles were not seen in the
surface of the polyimide film 1752. Therefore, it can be confirmed
that the satisfactory processing has been performed.
[0571] Moreover, the processing method is not limited to this, and
the processing may also be performed in the atmosphere.
30TH EMBODIMENT
[0572] FIGS. 72A and 72B are diagrams showing the manufacturing
steps of the semiconductor device according to a 30th embodiment of
the present invention. FIGS. 72A and 72B show the steps of
laser-processing a metal film 1762 formed on the silicon wafer 1701
via silicon oxide films 1761. In the present embodiment, a copper
film is used as the metal film 1762. The surface of the copper film
1762 is exposed with laser ablation. The optically processed copper
film 1762 is used, for example, in a wiring for electrically
connecting the device to another device, power supply wiring for
supplying a power, electrode, and the like.
[0573] In the present embodiment, the processing apparatus shown in
FIG. 59 is used to perform the processing in the solution. The pure
copper film 1762 having a film thickness of 500 nm is exposed with
the fourth higher harmonic wave (wavelength 266 nm) of the Q-Switch
YAG laser and optically processed. The shape of the irradiation
region is longitudinal 100 .mu.m.times.lateral 200 .mu.m, and the
energy density per shot is 3 J/cm.sup.2/shot.
[0574] At the optical processing time, from the image obtained by
the CCD camera 222, the gas member diameter measurement unit 1261
measures the diameter of the bubble generated from the exposure
region by the exposure of the laser beam. As shown in FIG. 72A,
while the bubble 1705 exists above the exposure region, the next
exposure of the laser beam is not performed. As shown in FIG. 72B,
the bubble 1705 is carried by the solution flow, the gas member
diameter measurement unit 1261 confirms that the bubble 1705
disappears, and the exposure of the laser beam 1704 is resumed. The
above-described steps are repeated, the processing is
performed.
[0575] As a result of the SEM observation after the processing, the
pinholes or scattered metal particles were not seen in the
periphery of the processed region. Moreover, the film peels in the
edge portion were not observed. Therefore, it can be confirmed that
the satisfactory processing has been performed.
[0576] This effect is similarly achieved, even when the Q-Switch
YAG laser is changed to the third higher harmonic wave (wavelength
355 nm), second higher harmonic wave (wavelength 532 nm), and basic
wave (wavelength 1064 nm). That is, with the light having the
wavelength absorbed by a thin copper film, the thin copper film on
the wafer can satisfactorily be processed.
[0577] The example in which the copper film is used as the metal
film 1762 has been described. However, a compound film in which
nickel and chromium films are stacked to enhance corrosion
resistance, single-layer film of an aluminum, aluminum alloy
(Al--Si, Al--Cu, Al--Cu--Si, and the like) film, compound film in
which a barrier metal film or anti-reflection film is stacked on
the above-described metal layer can be ablated. Even in this case,
a similar effect is obtained.
[0578] It is to be noted that the apparatus shown in FIG. 60 may
also be used to perform the processing in an atmosphere.
31ST EMBODIMENT
[0579] The laser processing onto the semiconductor wafer is
expected as a dicing technique for cutting out wafer chips.
Especially while the semiconductor chip is progressively thinned,
or the pattern is progressively miniaturized, as the method of
cutting out the semiconductor chip, a pre-dicing technique is
effective comprising: forming a trench halfway from the
semiconductor wafer surface beforehand (half cut); and thereafter
polishing and separating the back surface of the semiconductor
wafer until reaching the half cut trench.
[0580] FIGS. 73A and 73B are diagrams showing the manufacturing
steps of the semiconductor device according to a 31st embodiment of
the present invention. The processing apparatus shown in FIG. 59 is
used to perform the processing in the solution. The processing is
performed by the exposure with the fourth higher harmonic wave
(wavelength 266 nm) of the Q-Switch YAG laser. The shape of the
exposure region of the laser beam at the processing time is a
rectangular shape with 10 .mu.m in a short-side direction and 500
.mu.m in a long-side direction. The energy density per shot of the
laser beam is 4 J/cm.sup.2/shot. The exposure region of the laser
beam is relatively scanned against a semiconductor wafer 1770 at a
speed of 10 mm/sec in the long-side direction to form a dicing line
(trench) around each semiconductor device. Moreover, the formed
trench has a width of about 10 .mu.m and depth of 50 .mu.m. In the
processing process, the size of the bubble generated from the
exposure region by the laser beam is observed.
[0581] At the optical processing time, from the image obtained by
the CCD camera 222, the gas member diameter measurement unit 1261
measures the diameter of the bubble generated from the exposure
region by the exposure of the laser beam. As shown in FIG. 73A,
while the bubble 1705 exists above the exposure region, the next
exposure of the laser beam is not performed. As shown in FIG. 73B,
the bubble 1705 is carried by the solution flow, the gas member
diameter measurement unit 1261 confirms that the bubble 1705 has
disappeared, and the exposure of the laser beam 1704 is resumed.
The above-described steps are repeated, the processing is
performed. After the processing, the semiconductor wafer 1770 is
polished from a back surface side and separated.
[0582] As a result of the SEM observation after the processing, the
pinholes or scattered silicon wastes were not seen in the vicinity
of the whole region to be ablated. Moreover, the film peels in the
edge portion of the whole region to be ablated were not observed.
Therefore, it can be confirmed that the satisfactory processing has
been performed.
[0583] In the above-described optical processing, the fourth higher
harmonic wave (wavelength 266 nm) of the Q-Switch YAG laser is
used. However, this effect is similarly achieved, even when the
Q-Switch YAG laser is changed to the third higher harmonic wave
(wavelength 355 nm), second higher harmonic wave (wavelength 532
nm), and basic wave (wavelength 1064 nm). Additionally, with the
light having a wavelength absorbed by the silicon wafer, the
silicon wafer can satisfactorily be processed. Moreover, the
processing apparatus shown in FIG. 60 may also be used to perform
the processing in the atmosphere.
[0584] Furthermore, in FIG. 60 the dicing line is formed in the
silicon wafer, and the technique of forming the dicing line by the
present processing method can also be applied to the separation of
the device of the light emitting diode or semiconductor laser
formed of compound semiconductors such as Ga, P, As, In, Al.
32ND EMBODIMENT
[0585] In addition to the pre-dicing method described in the 31st
embodiment, the present processing method can also be used in a
technique of finally dicing the silicon wafer thinned beforehand.
FIGS. 74A to 74D are diagrams showing the manufacturing steps of
the semiconductor device according to a 32nd embodiment. FIGS. 74A
to 74D are diagrams showing this post-dicing process.
[0586] First, as shown in FIG. 74A, a device layer 1782 of a
silicon wafer 1781 is held by a dicing tape 1783. Here, the
semiconductor device and multilayered wiring layer are formed in
the device layer 1782. A passivation layer is formed in the
uppermost layer of the device layer 1782.
[0587] Subsequently, as shown in FIG. 74B, the silicon wafer 1781
is mechanically polished from the back surface, and the silicon
wafer 1781 is formed into a thin film. In the polished surface of
the thin-film silicon wafer 1781, a fractured layer is formed
because of a mechanical stress and intense deterioration. To
prevent the intense deterioration, the fractured layer is removed
by wet etching, and chip strength is inhibited from dropping.
[0588] Subsequently, as shown in FIG. 74C, the dicing tape 1783 is
removed. Subsequently, the wafer is turned over and the back
surface of the silicon wafer 1781 is held by a dicing tape
1784.
[0589] Subsequently, as shown in FIG. 74D, the device layer 1782 is
processed to be ablated with the light. In the present embodiment,
the processing apparatus shown in FIG. 59 is used to perform the
processing in the solution. The processing is performed by the
exposure with the fourth higher harmonic wave (wavelength 266 nm)
of the Q-Switch YAG laser. The energy density per shot of the laser
beam is 4 J/cm.sup.2/shot.
[0590] In the processing process, in the same manner as described
above, from the image obtained by the CCD camera 222, the gas
member diameter measurement unit 1261 measures the diameter of the
bubble generated from the exposure region by the exposure of the
laser beam. As shown in FIG. 73A, while the bubble 1705 exists
above the exposure region, the next exposure of the laser beam is
not performed. As shown in FIG. 73B, the bubble 1705 is carried by
the solution flow, the gas member diameter measurement unit 1261
confirms that the bubble 1705 has disappeared, and the exposure of
the laser beam 1704 is resumed. The above-described steps are
repeated, the processing is performed. While the above-described
steps are repeated, the wafer 1781 is exposed with the light,
processed, and cut. Thereby, micro processing wastes can be
prevented from sticking to the device layer 1782.
[0591] When a blade is used to perform the dicing, a chip side wall
is damaged, and the chip strength drops. Moreover, in a region
having a thickness of 50 .mu.m or less, the chip is cracked during
the dicing by the blade, and there is a problem that the yield
drops. On the other hand, the present processing method can be used
to form the dicing line without breaking any chip even in the wafer
thickness of 50 .mu.m or less. Moreover, the processing apparatus
shown in FIG. 60 may also be used to perform the processing in the
atmosphere.
33RD EMBODIMENT
[0592] FIGS. 75A and 75B are diagrams showing the manufacturing
steps of the semiconductor device according to a 33rd embodiment of
the present invention. FIGS. 75A and 75B show the steps of removing
an anti-reflection film 1793 and resist 1794 on alignment marks
1792 by the laser processing. The alignment marks 1792 are
buried/formed in an insulating film 1791 formed on the silicon
wafer 1701.
[0593] At the optical processing time, from the image obtained by
the CCD camera 222, the gas member diameter measurement unit 1261
measures the diameter of the bubble generated from the exposure
region by the exposure of the laser beam. As shown in FIG. 75A,
while the bubble 1705 exists above the exposure region, the next
exposure of the laser beam is not performed. As shown in FIG. 75B,
the bubble 1705 is carried by the solution flow, the gas member
diameter measurement unit 1261 confirms that the bubble 1705 has
disappeared, and the exposure of the laser beam 1704 is resumed.
The above-described steps are repeated, the processing is
performed.
[0594] As a result of the SEM observation after the processing, the
pinholes or resist film wastes were not seen in the treated
substrate surface. Moreover, the film peels in the edge portion of
the whole region to be ablated were not observed. When the surface
is processed without being influenced by the scattering by the
bubbles remaining above the exposure region, the alignment mark can
be exposed without any processing defect.
[0595] It is to be noted that the processing apparatus shown in
FIG. 60 may also be used to perform the processing in the
atmosphere.
34TH EMBODIMENT
[0596] A global wiring extends over circuit blocks on the chips,
and is an upper-layer wiring which supplies global clocks. Since
the wiring is a long-distance wiring, it is necessary to reduce
wiring delay as much as possible, and it is important to reduce
resistance. Therefore, the above-described optical processing
method is effectively applied in which the generation of the micro
particles and pinholes can effectively be inhibited.
[0597] FIGS. 76A to 76F are sectional views showing the
manufacturing steps of the semiconductor device according to a 34th
embodiment of the present invention. FIGS. 76A to 76F show the
steps of forming a single-layer global wiring.
[0598] First, as shown in FIG. 76A, a substrate is prepared
including pads 1802 formed on the silicon wafer 1701 vian an
insulating film 1801. Subsequently, as shown in FIG. 76B, a thin
metal film 1803 such as Cu/Ta/TaN, Pd/Ti/Ni is formed on the whose
surface of the insulating film 1801 and pads 1802. Subsequently, as
shown in FIG. 76C, a resin insulating film 1804 is formed on the
thin metal film 1803.
[0599] Subsequently, as shown in FIG. 76D, the resin insulating
film 1804 on the pads formed below layer is exposed with the light,
and the trench is formed in the resin insulating film 1804. In the
processing process, in the same manner as described above, from the
image obtained by the CCD camera 222, the gas member diameter
measurement unit 1261 measures the diameter of the bubble generated
from the exposure region by the exposure of the laser beam. While
the bubble 1705 exists above the exposure region, the next exposure
of the laser beam is not performed. The gas member diameter
measurement unit 1261 confirms that the bubble 1705 has
disappeared, and the exposure of the laser beam 1704 is resumed.
The above-described steps are repeated, the processing is
performed.
[0600] When the optical processing is performed, the satisfactory
pattern can be formed in the processed surface without the pinholes
or particles.
[0601] Subsequently, as shown in FIG. 76E, Cu, Au, solder, and the
like are buried in the trench formed in the resin insulating film
1804 to form a plated layer 1805 by electrolytic plating. Finally,
as shown in FIG. 76F, the resin insulating film 1804 is removed by
an organic solvent, and acids such as acetic acid, hydrochloric
acid, nitric acid, and rare hydrofluoric acid are used to remove
the metal film 1803. Thereby, the global metal wiring and metal
bumps are formed.
[0602] In this method, an expensive mask for exposure or CMP is not
required as in the related-art lithography process, and the wiring
can be accurately formed on the substrate. It is to be noted that
the processing apparatus shown in FIG. 60 may also be used to
perform the processing in an atmosphere.
35TH EMBODIMENT
[0603] FIGS. 77A to 77H are sectional views showing the
manufacturing steps of the semiconductor device according to a 35th
embodiment of the present invention. FIGS. 77A to 77H show the
steps of forming a multilayered global wiring. First, as shown in
FIG. 77A, a substrate is prepared including the pads 1802 formed on
the silicon wafer 1701 via the insulating film 1801. Subsequently,
as shown in FIG. 77B, a first resin insulating film 1811 is formed
on the insulating film 1801.
[0604] Next, a predetermined portion of the first resin insulating
film 1811 is irradiated with the laser beam to perform the optical
processing. The apparatus shown in FIG. 59 is used to perform the
optical processing in the solution flow. In the optical processing,
as shown in FIG. 77C, the first resin insulating film 1811 on the
pads 1802 is removed, and via-holes in which the pads are exposed
are formed.
[0605] Subsequently, as shown in FIG. 77D, a metal film 1812 such
as Cu/Ta/TaN, Pd/Ti/Ni is formed on the first resin insulating
film. Subsequently, as shown in FIG. 77E, a second resin insulating
film 1813 is formed on the metal film 1812. Subsequently, the
second resin insulating film 1813 is irradiated with the laser beam
again, and optically processed. In the optical processing, as shown
in FIG. 77F, the via-holes and wiring trenches are formed.
[0606] Subsequently, as shown in FIG. 77G, Cu, Au, and the like are
buried/formed in the via-holes and wiring trenches to form a plated
layer 1814 by the electrolytic plating. Finally, as shown in FIG.
77H, the second resin insulating film 1813 is removed by the
organic solvent. Furthermore, the thin metal film 1812 is etched by
the acid solution to form metal wirings.
[0607] In the above-described forming, without using the
photolithography process incurring a high manufacturing cost, the
multilayered wiring can be exactly formed with high
reliability.
[0608] The above-described steps can also be applied in forming
solder or Au bumps on the semiconductor device surface, or forming
the global wiring, or wiring on a packaged substrate.
[0609] Moreover, for the processing method, a satisfactory
processing method may appropriately be selected from the processing
method described in the 27th Embodiment.
36TH EMBODIMENT
[0610] In recent years, a chip-on-chip technique of forming a
through hole in the semiconductor device and stacking the
semiconductor chips which are metal wirings such as Cu buried in
the through hole has been noted.
[0611] FIG. 78 is a sectional view showing the semiconductor device
of a chip-on-chip type according to a 36th embodiment of the
present invention. As shown in FIG. 78, a second chip 1830 is held
between first and third chips 1820 and 1840 including metal bumps
1851, 1852 on pads 1823, 1843. The second chip 1830 includes
through plugs 1837 having through holes filling-metal. By
connection among the stacked chips, a wiring length can be largely
reduced, and wiring delay can be suppressed. It is to be noted that
in FIG. 78 reference numerals 1821, 1831, 1841 denote silicon
wafers, reference numerals 1822, 1832, 1842 denote device layers,
1835 denotes a passivation layer, and 1836 denotes a side-wall
insulating film.
[0612] At present, the through holes are made/processed by RIE.
However, a processing rate is slow and productivity is low.
[0613] FIGS. 79A to 79H are sectional views showing the
manufacturing steps of the semiconductor device according to the
36th embodiment of the present invention. FIGS. 79A to 79H show an
example of steps of forming the through hole in the chip for use in
the semiconductor device of the chip-on-chip type. First, as shown
in FIG. 79A, a substrate is prepared in which a semiconductor
device (not shown) and silicon oxide film 1861 are formed on a
silicon wafer 1831. When the laser processing is performed in a
method similar to that of the 27th embodiment, a through hole 1862
is formed in the silicon oxide film 1861 and silicon wafer 1831.
Here, apparatus as shown in FIG. 59 is used to ablate the region.
Subsequently, as shown in FIG. 79B, a second silicon oxide film
1836 is formed on the surface of the through hole 1862.
[0614] Subsequently, as shown in FIG. 79C, a metal film 1837 is
formed on the through hole 1862 and the second silicon oxide film
1836. Subsequently, as shown in FIG. 79D, the surface of the metal
film 1837 is flattened, and the through plug 1837 is formed in the
through hole 1862. Subsequently, as shown in FIG. 79E, an
interlayer insulating film 1863 is formed on the second silicon
oxide film 1836, and pad 1834 is formed in the interlayer
insulating film 1863. It is to be noted that reference numerals
1861, 1836, 1863 on the silicon wafer 1831 correspond to the device
layer 1832.
[0615] Subsequently, as shown in FIG. 79F, the silicon substrate is
formed into the thin film by polishing. Subsequently, as shown in
FIG. 79G, the passivation layer is formed on the back surface of
the silicon wafer 1831. Subsequently, as shown in FIG. 79H, the
surface of the passivation layer 1835 is flattened to expose the
through plug 1837 and to form a connection surface with the
bump.
[0616] By the present processing method, a satisfactory processed
shape is achieved without pinholes or particles, which enhances the
operation reliability of the final semiconductor device.
[0617] Moreover, the apparatus shown in FIG. 60 may also be used to
perform the processing in the atmosphere.
37TH EMBODIMENT
[0618] In a 37th embodiment, a step of using the optical processing
apparatus described in the 26th embodiment to process a photoresist
film which is the organic material formed on the aluminum film will
be described. It is to be noted that in the present embodiment,
instead of the gas member diameter measurement unit 1261, a control
unit is disposed to control at least one of the exposure position
of the laser beam at the exposure irradiation timing of the laser
beam and the scan speed with respect to the substrate.
[0619] The aluminum film formed on the semiconductor substrate
(wafer) having a diameter of 300 mm is coated with the photoresist
film by a spin coat process, and subsequently heated to form the
photoresist film having a film thickness of 1 .mu.m on the aluminum
film. Next, the third higher harmonic wave (wavelength 355 nm) of
the Q-Switch YAG laser is exposed to ablate the photoresist film in
the whole region to be exposed. Here, the energy density per pulse
was set to 0.5 J/cm.sup.2/pulse. The ablation was performed in a
state in which pure water flows.
[0620] The exposure region has a slit shape having a length of 80
.mu.m and width of 5 .mu.m, and a substrate hold mechanism is
relatively scanned against exposure light. The region to be ablated
was set to 80 .mu.m.times.100 .mu.m, and the number of scans is
twice for reciprocation.
[0621] FIGS. 80A and 80B are plan views showing a relation between
the processed region and solution flow. In a first scan, as shown
in FIG. 80A, an exposure region 1872 relatively scans to the right
from the left against the whole region to be ablated 1871. At this
time, the direction of a solution flow 1873a is set to be opposite
to a scan direction. When the scan direction and the solution flow
direction are reversed, the bubble generated by the exposure moves
toward a downstream side, and the next exposure is not influenced.
In a second scan after the end of the whole region to be ablated is
reached, as shown in FIG. 80B, the direction of a solution flow
1873b is set so as to change to a direction opposite to the
direction at the first scan time. Here, the speed of the flowing
liquid was set to 1 m/s.
[0622] A process for obtaining an optimum oscillation frequency of
laser will be described hereinafter. Assuming the scan speed is v
(.mu.m/s), and the oscillation frequency of laser is f (1/s), a
movement distance x per pulse is represented by x=v/f. When the
movement distance x per pulse is smaller, the number of superposed
exposures increases, and therefore the exposed energy amount
increases. On the other hand, when the movement distance x
increases, the exposed energy amount decreases.
[0623] Moreover, when the laser is repeatedly emitted to remove the
processed film, ablation reaction is promoted by heat storage
effect with the increase of the frequency f. The present inventors
have noted v/f.sup.2 obtained by dividing the movement distance x
per pulse by the frequency f. That is, it has been considered that
the irradiation reaction progresses with the decrease of v/f.sup.2.
Here, the scan speeds are set to 1000 .mu.m/sec and 80 .mu.m/sec,
and the oscillation frequency f of the laser is changed. It is seen
from FIG. 81 that a range of v/f.sup.2 indicating a small total
defect arean and satisfactory processing characteristic is not less
than about 6.0.times.10.sup.-5 (.mu.msec) and not more than
1.0.times.10.sup.-3 (.mu.msec). In the region where v/f.sup.2 is
small, the irradiation reaction excessively progresses as described
above, and therefore the photoresist film, which is a mask
material, changes in properties and forms the defect. On the other
hand, in the region where v/f.sup.2 is large, conversely the
ablation reaction is insufficient, and the photoresist film is
insufficiently removed, which forms defects.
[0624] From the result of FIG. 81, a center of the satisfactory
v/f.sup.2 range was obtained, and a condition of v/f.sup.2 was set
to 3.0.times.10.sup.-4 (.mu.msec). When the scan speed v was set to
1000 .mu.m/sec, oscillation frequency f=1825 Hz was obtained.
[0625] It is to be noted that on this condition the bubble
generated by the previous irradiation was quickly transported
toward the downstream side by the flowing liquid and did not exist
at the next irradiation time. Therefore, a satisfactory processing
can be performed without the bubble causing any processing
defect.
[0626] On the above-described condition, after ending the
processing of the photoresist film by the laser irradiation, the
wafer was submerged in an etching solution for aluminum, and the
photoresist film was used as a mask to selectively etch the
aluminum film. Subsequently, the photoresist film, which was the
mask material, was removed. When the processed state was observed
by an optical microscope, satisfactory patterning was confirmed
without any defect.
[0627] As described above, the movement distance x per pulse is
divided by the frequency f to obtain v/f.sup.2 as the
above-described range, and it is possible to realize a satisfactory
rough patterning without any defect.
[0628] It is to be noted that in the present embodiment the scan
speed v is set to 1000 .mu.m/sec, but the present invention is not
limited to this. A combination of the scan speed v and oscillation
frequency f, which satisfies an optimum value of v/f.sup.2, may be
obtained. From a viewpoint of reduction of treatment time, the scan
speed is preferably high.
[0629] In the present embodiment, the slit width was set to 5
.mu.m, but is not limited to this. A similar effect can be obtained
with a slit range of 2 .mu.m to 20 .mu.m, and this was confirmed by
experiment. From a viewpoint of the processed shape, a slit width
in the range of 2 .mu.m to 5 .mu.m is preferable.
[0630] Moreover, in the present embodiment, the third higher
harmonic wave of the Q-Switch YAG laser is used as the light source
for the processing, but the light source is not limited to this,
and the fourth higher harmonic wave (wavelength 266 nm) of the
Q-Switch YAG laser, pulse laser such as the KrF excimer laser, and
lamp light may also be used.
[0631] Moreover, in the present embodiment, the processing of the
photoresist film on the aluminum film has been described, but the
present invention is not limited to this, and can also be applied
to another organic film.
[0632] Furthermore, the energy density per pulse was set to 0.5
J/cm.sup.2/pulse in the present embodiment, but is not limited to
this. The energy density per pulse is set to a value at which
satisfactory patterning is possible without any defect, and thereby
a similar effect can be obtained.
38TH EMBODIMENT
[0633] In the present embodiment, an example will be described in
which the optical processing apparatus including the apparatus
constitution described in the 26th embodiment is used and applied
to various types of processing required in the manufacturing
process of the semiconductor device.
[0634] A semiconductor substrate (wafer) having a diameter of 300
mm was coated with a coat spun on carbon film by a spin coat
process to form the film having a thickness of 300 nm. Next, the
third higher harmonic wave (wavelength 355 nm) of the Q-Switch YAG
laser was used to remove the region to be removed in the film.
Here, the energy density per pulse was set to 0.35
J/cm.sup.2/pulse. The exposure was performed in the state of the
flowing pure water.
[0635] For the exposure region, as shown in FIG. 82, a slit-shaped
exposure region 1881 having a width a (.mu.m) and length b (.mu.m)
was used. The conditions of the width a (.mu.m) and length b
(.mu.m) were changed to change the size of the exposure region
1881, and particle amount per pulse was evaluated.
[0636] FIG. 83 shows a relation between total sum of areas of
particles and total sum of the length (hereinafter referred to as
total extension of the side) of the side of the slit-shaped
exposure region represented by 2.times.(a+b).
[0637] As shown in FIG. 83, in the range where the total extension
of the side is 180 .mu.m or more, as the total extension of the
side increases the total sum of particle areas increases. Moreover,
in the range where the total sum of the length of the side is 180
.mu.m or less, as the total length of the side decreases, the total
sum of particle areas remarkably decrease. That is, it has been
clarified by experiment that the total extension of the side is
preferably 180 .mu.m or less in order to perform the processing
with few particles.
[0638] From this result, the exposure region was set to have a
width of 5 .mu.m and length of 80 .mu.m, and the processing was
performed by the exposure. For the exposure region condition, since
the total extension of the side is 170 .mu.m, the above-described
condition is satisfied.
[0639] The exposure region was relatively scanned against the
substrate hold mechanism, and the substrate were relatively scanned
against exposure light. The whole region to be ablated was set to
80 .mu.m.times.100 .mu.m, and the number of scans were set to two
for the reciprocation. The scan speed v was set to 600 .mu.m/sec,
and the oscillation frequency f was set to 1414 Hz. Since the
relation between the scan direction and flowing liquid is similar
to that of the 37th embodiment, the detailed description is omitted
here.
[0640] The ablation was performed with the exposure region whose
shape a width of 40 .mu.m and length of 80 .mu.m on which the
exposure region does not satisfy the above-described conditions. In
this case, a large number of particles were generated.
[0641] On the other hand, when the ablation was performed with the
exposure region satisfying the above-described conditions and
having a width of 5 .mu.m and length of 80 .mu.m, it was possible
to obtain remarkably satisfactory processing characteristics with
few particles.
[0642] When the total sum of the lengths of the side of the
slit-shaped exposure region was set to 180 .mu.m or less, it was
possible to realize a remarkably satisfactory processing with few
particles.
[0643] It is to be noted that in the present embodiment the scan
speed v was set to 600 .mu.m/sec, but is not limited to this, and
can appropriately be changed.
[0644] Moreover, in the present embodiment, the exposure region has
the total sum of the length of the side of 170 .mu.m, width of 5
.mu.m, and length of 80 .mu.m, but is not limited to this. The
total length of the side with fewer particles is preferably 160
.mu.m.
[0645] Furthermore, the third higher harmonic wave of the Q-Switch
YAG laser is used as the light source for the processing, but the
light source is not limited to this, and the fourth higher harmonic
wave (wavelength 266 nm) of the Q-Switch YAG laser, pulse laser
such as the KrF excimer laser, lamp light, or ion or electron beam
may also be used.
[0646] Additionally, in the present embodiment, the processing of
the spun on carbon film has been described, but the present
invention is not limited to this, and can also be applied to
another material.
[0647] Moreover, the energy density per pulse was set to 0.35
J/cm.sup.2/pulse in the present embodiment, but is not limited to
this. The energy density per pulse is set to the value at which the
satisfactory patterning is possible without any defect, and thereby
a similar effect can be obtained.
[0648] Furthermore, in the present embodiment, a rectangular region
(FIG. 84A) is used as the slit-shaped irradiation region, but the
region is not limited to this. For example, the region may have
shapes shown in FIGS. 84B to 84D. In this case, the total sum of
lengths of sides in the present embodiment corresponds to a contour
length.
[0649] It is to be noted that the method of the present embodiment
can also be applied to the processing methods described in the 23rd
to 25th embodiments. That is, the contour length of the exposure
region (processing unit) is preferably set to 180 .mu.m or
less.
[0650] Additional advantages and modifications will readily occur
to those skilled in the art. Therefore, the invention in its
broader aspects is not limited to the specific details and
representative embodiments shown and described herein. Accordingly,
various modifications may be made without departing from the spirit
or scope of the general inventive concept as defined by the
appended claims and their equivalents.
* * * * *