U.S. patent application number 09/935034 was filed with the patent office on 2001-12-20 for apparatus for processing substrate using process solutions having desired mixing ratios.
This patent application is currently assigned to Shibaura Mechatronics Corporation. Invention is credited to Iso, Akinori, Nishibe, Yukinobu.
Application Number | 20010052354 09/935034 |
Document ID | / |
Family ID | 26533722 |
Filed Date | 2001-12-20 |
United States Patent
Application |
20010052354 |
Kind Code |
A1 |
Nishibe, Yukinobu ; et
al. |
December 20, 2001 |
Apparatus for processing substrate using process solutions having
desired mixing ratios
Abstract
A substrate is processed with a first process solution prepared
by mixing sulfuric acid with a hydrogen peroxide solution, followed
by processing the substrate with a second process solution. After
the substrate is processed with the first process solution, the
supply of sulfuric acid is stopped, with the hydrogen peroxide
alone being supplied to the substrate. Then, the supply of the
hydrogen peroxide solution is stopped, and the substrate is rinsed
with a second process solution. The particular processing makes it
possible to prevent the second process solution from reacting with
sulfuric acid.
Inventors: |
Nishibe, Yukinobu;
(Kanagawa-ken, JP) ; Iso, Akinori; (Kanagawa-ken,
JP) |
Correspondence
Address: |
VOLPE AND KOENIG, P.C.
SUITE 400, ONE PENN CENTER
1617 JOHN F. KENNEDY BOULEVARD
PHILADELPHIA
PA
19103
US
|
Assignee: |
Shibaura Mechatronics
Corporation
Kanagawa-ken
JP
|
Family ID: |
26533722 |
Appl. No.: |
09/935034 |
Filed: |
August 22, 2001 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
09935034 |
Aug 22, 2001 |
|
|
|
09644170 |
Aug 23, 2000 |
|
|
|
6299697 |
|
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Current U.S.
Class: |
134/57R ;
134/100.1; 134/153; 134/18; 134/25.4; 134/25.5; 134/26; 134/28;
134/3; 134/30; 134/32; 134/33; 134/36; 134/41; 134/42; 134/902;
134/95.3; 134/98.1 |
Current CPC
Class: |
H01L 21/67028 20130101;
H01L 21/6708 20130101; G03F 7/423 20130101; H01L 21/67242
20130101 |
Class at
Publication: |
134/57.00R ;
134/95.3; 134/98.1; 134/100.1; 134/153; 134/902; 134/3; 134/18;
134/25.4; 134/25.5; 134/26; 134/28; 134/30; 134/32; 134/33; 134/36;
134/41; 134/42 |
International
Class: |
B08B 003/02; B08B
003/14; C23G 001/02; B08B 007/04; B08B 009/20; B08B 003/00; B08B
001/02; B08B 007/00 |
Foreign Application Data
Date |
Code |
Application Number |
Aug 25, 1999 |
JP |
11-238493 |
Sep 27, 1999 |
JP |
11-273031 |
Claims
What is claimed is:
1. An apparatus for processing a substrate, in which the substrate
is successively processed with a plurality of different kinds of
process solutions, comprising: a spin chuck supporting the
substrate; a driving source for rotating the spin chuck; a nozzle
member for supplying a first process solution prepared by mixing
sulfuric acid and a hydrogen peroxide solution at a predetermined
mixing ratio to the substrate supported by the spin chuck and
second process solution for rinsing the substrate to the substrate;
a switching mechanism for selecting sulfuric acid, the hydrogen
peroxide solution and the second process solution supplied to the
nozzle member; a concentration adjusting mechanism for adjusting
the mixing ratio of sulfuric acid to the hydrogen peroxide
solution, which collectively form the first process solution,
supplied to the nozzle member; and a control device for controlling
the supply of sulfuric acid, the hydrogen peroxide solution and the
second process solution, which is switched by the switching
mechanism, and the adjustment of the mixing ratio of sulfuric acid
to the hydrogen peroxide solution, which is performed by the
concentration adjusting mechanism.
2. The apparatus for processing a substrate according to claim 1,
wherein each of a first supply pipe for supplying the sulfuric
acid, a second supply pipe for supplying the hydrogen peroxide
solution, and a third supply pipe for supplying the second process
solution is connected to the nozzle member.
3. The apparatus for processing a substrate according to claim 1,
wherein the switching mechanism consists of opening-closing valves
mounted to the first to third supply pipes.
4. The apparatus for processing a substrate according to claim 1,
wherein the concentration adjusting mechanism consists of the flow
rate control valves mounted to the first supply pipe and the second
supply pipe.
5. The apparatus for processing a substrate according to claim 1,
wherein a temperature sensor for detecting the temperature of the
first process solution is mounted to the nozzle member, and the
control device serves to control the concentration adjusting
mechanism in accordance with the temperature of the first process
solution detected by the temperature sensor so as to adjust the
concentrations of the sulfuric acid and the hydrogen peroxide
solution, which collectively form the first process solution.
6. The apparatus for processing a substrate according to claim 1,
wherein an angular velocity detecting sensor for detecting the
angular velocity of the spin chuck is connected to the control
device to enable the control device to control the concentration
adjusting mechanism depending on the angular velocity of the spin
chuck detected by the angular velocity detecting sensor so as to
adjust the mixing ratio of sulfuric acid to the hydrogen peroxide
solution, which collectively form the first process solution.
7. The apparatus for processing a substrate according to claim 1,
wherein a mixing mechanism for mixing sulfuric acid and a hydrogen
peroxide solution, which collectively form the first process
solution, supplied to the nozzle member is arranged within the
nozzle member.
8. The apparatus for processing a substrate according to claim 7,
wherein the nozzle member comprises a mixing chamber into which
said sulfuric acid and the hydrogen peroxide solution flow and a
spurting hole for spurting the mixture of the sulfuric acid and the
hydrogen peroxide solution flowing into the mixing chamber, and the
mixing mechanism consists of baffle members arranged within the
spurting hole for converting the streams of said sulfuric acid and
said hydrogen peroxide solution into an eddy current.
9. The apparatus for processing a substrate according to claim 1,
wherein an arm body having a distal end portion and a proximal end
portion is arranged above the spin chuck, said nozzle member being
mounted to the distal end portion, and a driving mechanism for
driving said arm body within a predetermined range of angle being
connected to the proximal end portion, and the nozzle member is
driven in the radial direction of the substrate held by the spin
chuck in accordance with rotation of the arm body.
Description
[0001] CROSS-REFERENCE TO RELATED APPLICATIONS
[0002] This application is a divisional of U.S. patent application
Ser. No. 09/644,170 which claims the benefit of and priority from
Japanese Patent Applications No. 11-238493, filed Aug. 25, 1999;
and No. 11-273031, filed Sep. 27, 1999. The entire contents of each
of the above mentioned related applications is hereby incorporated
by reference herein as if fully set forth.
BACKGROUND
[0003] The present invention relates to a method and apparatus for
processing a substrate by spraying a processing solution onto the
substrate.
[0004] The process of manufacturing a photo mask used in a liquid
crystal display device, a semiconductor device or in the
manufacture thereof includes a lithography step for forming a
circuit pattern on a substrate such as a glass substrate, a
semiconductor wafer or a quartz substrate by using the photo
mask.
[0005] For forming a circuit pattern on the substrate in the
lithography process, the steps of forming a resist pattern on the
substrate, etching the substrate by using the resist pattern as a
mask, removing the resist pattern after the etching step, and
forming a film on the substrate having the resist pattern removed
therefrom are repeated a plurality of times.
[0006] Where the substrate is a photo mask used in the manufacture
of a liquid crystal display device or a semiconductor device, an
insoluble resist that is unlikely to be dissolved in a solvent is
used for forming a pattern. If the pattern is formed by using the
insoluble resist, it is difficult to peel off the pattern by the
ordinary method. Thus, a plasma asking is employed for removing the
resist pattern.
[0007] However, the plasma asking invites an increased
manufacturing cost and a low through-put.
[0008] Under the circumstances, a new technique replacing the
plasma asking is disclosed in, for example, Japanese Patent
Disclosure (Kokai) No. 6-29270 and Japanese Patent Disclosure No.
6-291098. Specifically, it is disclosed that the resist pattern is
peeled off by using a mixed solution consisting of sulfuric acid
and hydrogen peroxide solution, followed by supplying a pure water
onto the substrate for the rinsing treatment.
[0009] However, the prior art exemplified above is defective in
that, in rinsing the substrate with a pure water after peeling of
the resist pattern off the substrate with the mixed solution, the
pure water tends to bring about a dissolving reaction with the
sulfuric acid remaining on the substrate. What should be noted is
that the dissolving reaction brings about the mist generation and
scattering of the sulfuric acid.
SUMMARY
[0010] An object of the present invention is to provide a method
and apparatus for processing a substrate, which permits suppressing
the dissolving reaction between sulfuric acid used as a first
process solution and a rinsing solution used as a second process
solution in the case where the substrate is processed with the
second process solution after the processing with the first process
solution.
[0011] According to a first aspect of the present invention, there
is provided a method of processing a substrate, in which the
substrate is processed successively with a plurality of different
kinds of process solutions, comprising:
[0012] a first step of processing the substrate with a first
process solution prepared by mixing sulfuric acid and hydrogen
peroxide solution;
[0013] a second step of supplying a hydrogen peroxide solution
alone to the substrate after completion of the processing with the
first process solution; and
[0014] a third step of supplying a second process solution for
rinsing the substrate to the substrate after supply of the hydrogen
peroxide solution alone for a predetermined period of time.
[0015] According to another aspect of the present invention, there
is provided an apparatus for processing a substrate, in which the
substrate is successively processed with a plurality of different
kinds of process solutions, comprising:
[0016] a spin chuck supporting the substrate;
[0017] a driving source for rotating the spin chuck;
[0018] a nozzle member for supplying a first process solution
prepared by mixing sulfuric acid and a hydrogen peroxide solution
at a predetermined mixing ratio to the substrate supported by the
spin chuck and second process solution for rinsing the substrate to
the substrate;
[0019] a switching mechanism for selecting sulfuric acid; the
hydrogen peroxide solution and the second process solution supplied
to the nozzle member;
[0020] a concentration adjusting mechanism for adjusting the mixing
ratio of sulfuric acid to the hydrogen peroxide solution, which
collectively form the first process solution, supplied to the
nozzle member;
[0021] and a control device for controlling the supply of sulfuric
acid, the hydrogen peroxide solution and the second process
solution, which is switched by the switching mechanism, and the
adjustment of the mixing ratio of sulfuric acid to the hydrogen
peroxide solution, which is performed by the concentration
adjusting mechanism.
[0022] Additional objects and advantages of the invention will be
set forth in the description which follows, and in part will be
obvious from the description, or may be learned by practice of the
invention. The objects and advantages of the invention may be
realized and obtained by means of the instrumentalities and
combinations particularly pointed out hereinafter.
BRIEF DESCRIPTION OF THE DRAWING(S)
[0023] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate presently
preferred embodiments of the invention, and together with the
general description given above and the detailed description of the
preferred embodiments given below, serve to explain the principles
of the invention.
[0024] FIG. 1 schematically shows the construction of a substrate
processing apparatus according to a first embodiment of the present
invention;
[0025] FIG. 2 shows the piping system for supplying a process
solution to the nozzle member;
[0026] FIG. 3A is a cross sectional view showing in a magnified
fashion a liquid spurting hole portion of the nozzle member;
[0027] FIG. 3B is a cross sectional view along the line 3B-3B shown
in FIG. 3A;
[0028] FIG. 4 is a time chart showing the timings of supplying
sulfuric acid, a hydrogen peroxide solution and a pure water;
[0029] FIG. 5 is a cross sectional view showing the nozzle member
according to a second embodiment of the present invention; and
[0030] FIG. 6 is a cross sectional view showing the nozzle member
according to a third embodiment of the present invention.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT(S)
[0031] Some embodiments of the present invention will now be
described with reference to the accompanying drawings.
[0032] FIGS. 1 to 4 collectively show a first embodiment of the
present invention. Specifically, FIG. 1 shows a processing
apparatus of a substrate. As shown in the drawing, the processing
apparatus comprises a cup body 1 consisting of a lower cup 1a
having a bottom and an open upper end, an upper cup 1b detachably
mounted to the upper end of the lower cup 1a, and an intermediate
cup 1c detachably mounted to the inner surface of the upper cup 1b
by a screw 2.
[0033] A through-hole 3 is formed in the central portion of the
bottom portion of the lower cup 1a. A rotary shaft 4 is inserted
into the through-hole 3. The upper end of the rotary shaft 4
projecting into the cup body 1 is mounted to the lower surface of a
spin chuck 5 arranged within the cup body 1. A substrate 6 such as
a glass substrate used in a liquid crystal display device is
mounted on the upper surface of the spin chuck 5. The spin chuck 5
is provided with a plurality of support pins 7 for supporting the
lower surface of the substrate 6 and with a plurality of engaging
pins 8 engaged with the outer circumferential surface of the
substrate 6.
[0034] The lower end portion of the rotor 4 projecting to the
outside of the lower cup 1a through the through-hole 3 is joined to
a rotary shaft 9a of a first motor 9. It follows that, if the first
motor 9 is rotated, the spin chuck 5 is rotated together with the
substrate 6.
[0035] The first motor 9 is mounted to a first mounting plate 11.
The first mounting plate 11 can be moved up and down by a first
cylinder 12. If the first mounting plate 11 is moved upward, the
spin chuck 5 is moved from the upper surface of the cup body 1 to
reach a height denoted by broken line in FIG. 1. As a result, the
substrate 6 can be mounted to and removed from the spin chuck 5 by,
for example, a robot (not shown).
[0036] A support body 13 is mounted to the upper surface of the
first mounting plate 11. The support body 13 is provided with a
bearing 13a rotatably supporting the rotary shaft 4. A supporting
leg 14 is mounted to the support body 13. The supporting leg 14
projects upward into the lower cup 1a through the through-hole 3,
and a cover 15 covering the through-hole 3 is mounted to the upper
end of the supporting leg 14. The cover 15 is moved up and down
together with the spin chuck 5. It follows that, even when the spin
chuck 5 is in the elevated position, the cover 15 covers the
through-hole 3.
[0037] The cover 15 is inclined downward in the radial direction
from the center toward the periphery. Therefore, the process
solution dripping onto the upper surface of the cover 15 flows
along the inclined surface so as to drip into the lower cup 1a. A
plurality of discharge pipes 16 are connected to the bottom portion
of the periphery of the lower cup 1a so as to permit the process
solution dripping into the lower cup 1a to be discharged to the
outside. Incidentally, a suction pump (not shown) is connected to
the discharge pipe 16.
[0038] A nozzle member 31 for spurting a process solution onto the
substrate 6 held by the spin chuck 5 is arranged above the spin
chuck 5. The nozzle member 31 is rocked in the radial direction of
the substrate 6 by a rotating mechanism 32. The rotating mechanism
32 is provided with a cylindrical horizontal arm 33, and the nozzle
member 31 is mounted to a tip portion 33a of the horizontal arm
33.
[0039] A connecting member 35 is mounted to a proximal end portion
33b of the horizontal arm 33. The upper end of a hollow spline
shaft 34 extending in a vertical direction and acting as a driving
shaft is joined to the connecting member 35. The spline shaft 34
extends through a through-hole 37 formed in a second support plate
36. The lower end portion of the spline shaft 34 is rotatably
supported by a bearing 39, which is mounted to one end portion of a
crank-shaped mounting plate 38.
[0040] A second cylinder 41 is mounted to the second support plate
36. A rod 41a of the second cylinder 41 is joined to the other end
portion of the mounting plate 38. Therefore, if the rod 41a of the
second cylinder 41 is moved upward into the second cylinder 41, the
spline shaft 34 is driven upward via the mounting plate 38.
[0041] A driven pulley 42 is mounted to an intermediate portion of
the spline shaft 34 such that the driven pulley 42 is capable of
sliding along the spline shaft 34 and rotatable together with the
spline shaft 34. A second motor 43 is mounted to the second support
plate 36. A driving pulley 44 is engaged with a rotary shaft 43a of
the second motor 43. Further, a timing belt 45 is stretched between
the driving pulley 44 and the driven pulley 42. It follows that, if
the second motor 43 is rotated, the spline shaft 34 is also
rotated.
[0042] If the spline shaft 34 is rotated, the horizontal arm 33 is
interlocked with the rotation of the spline shaft 34. Therefore,
the nozzle member 31 mounted to the tip portion 33a of the
horizontal arm 33 is moved in the radial direction the substrate 6
held by the spin chuck 5. In other words, the horizontal arm 33 is
reciprocated within a predetermined range of angle by the second
motor 43.
[0043] Incidentally, the movement of the driven pulley 42 in the
vertical direction is restricted by a holding member (not shown),
though the rotation of the driven pulley 42 is not inhibited.
Therefore, even if the spline shaft 43 is driven in the vertical
direction by the second cylinder 41, the driven pulley 42 is not
moved in the vertical direction together with the spline shaft
34.
[0044] The nozzle member 31 includes a nozzle body 51 as shown in
FIG. 2. A mixing chamber 52 is formed within the nozzle body 51,
and formed is a spurting hole 53 with one end communicating with
the mixing chamber 52 and the other end open at the tip surface of
the nozzle body 51.
[0045] Connected to the mixing chamber 52 are a first supply pipe
54, a second supply pipe 55 and a third supply pipe 56. Sulfuric
acid (H2SO4) is supplied through the first pipe 54 into the mixing
chamber 52. Also, a hydrogen peroxide (H2O2) solution is supplied
through the second supply pipe 55 into the mixing chamber 55. The
sulfuric acid and the hydrogen peroxide solution are mixed within
the mixing chamber 52 so as to prepare a first process solution. On
the other hand, a pure water for rinsing the substrate 6 is
supplied as a second process solution through the third supply pipe
56 into the mixing chamber 52.
[0046] Heat of solution is generated when the sulfuric acid and the
hydrogen peroxide solution are mixed within the mixing chamber 52
for preparing the first process solution. As a result, the
temperature of the first process solution is spurted through the
spurting hole 53 of the nozzle member 31 toward the substrate 6.
The temperature of the first process solution can be controlled by
changing the mixing ratio of the sulfuric acid to the hydrogen
peroxide solution.
[0047] It is possible for the sulfuric acid and the hydrogen
peroxide solution not to be mixed sufficiently within the mixing
chamber 52 of the nozzle member 31 so as to be spurted separately
through the spurting hole 53 toward the substrate 6. In such a
case, the temperature of the first process solution is not
sufficiently elevated, resulting in failure to process the
substrate 6 sufficiently and smoothly.
[0048] To overcome the above-noted difficulty, each of the first
and second process solutions supplied into the mixing chamber 52 of
the nozzle member 31 is sufficiently mixed by a mixing mechanism 60
mounted within the nozzle member 31 and, then, spurted through the
spurting hole 53 toward the substrate 6.
[0049] As shown in FIGS. 3A and 3B, the mixing mechanism 60
comprises two baffle members 62a, 62b arranged within the spurting
hole 53. Each of these baffle members 62a, 62b is substantially
semicircular and sized slightly larger than a half of the cross
sectional size of the spurting hole 53. Also, these baffle members
62a, 62b are arranged a predetermined distance apart from each
other in the axial direction of the spurting hole 53 and arranged
deviant from each other by substantially 180.degree. in the
circumferential direction.
[0050] Because of the presence of the baffle members 62a, 62b, each
of the first and second process solutions flowing from the mixing
chamber 52 into the spurting hole 53 forms an eddy current as
denoted by arrows in FIG. 3A. It follows that, even if each of
these process solutions is not sufficiently mixed within the mixing
chamber 52, each of these process solutions is sufficiently mixed
when passing through the spurting hole 53.
[0051] A first opening-closing valve 61 and a first flow rate
control valve 62 are mounted to the first supply pipe 54. Also, a
second opening-closing valve 63 and a second flow rate control
valve 64 are mounted to the second supply pipe 55. Further, a third
opening-closing valve 65 is mounted to the third supply pipe
56.
[0052] The operation of each of these first, second and third
opening-closing valves 61, 63, 65 is controlled by a control device
71. Likewise, the degree of opening of each of the first and second
flow rate control valves 62 and 64 is controlled by the control
device 71.
[0053] The control device 71 controls the degree of opening of each
of the flow rate control valves 62 and 64 in accordance with the
peripheral speed of the substrate 6 that is determined by the
diameter and the angular velocity of the substrate 6. As a result,
the spurting amount of the first process solution spurted from the
nozzle member 31 toward the substrate 6 and the mixing ratio of
sulfuric acid and the hydrogen peroxide solution are
controlled.
[0054] The angular velocity of the substrate 6, i.e., the angular
velocity of the spin chuck 5, is detected by an angular velocity
detecting sensor 72 mounted to the first motor 9, and a signal
denoting the detected angular velocity is supplied to the control
device 71.
[0055] Where the first process solution is supplied to the central
portion of the substrate 6, the temperature drop in the peripheral
portion of the substrate 6, compared with the temperature in the
central portion, is increased with increase in the peripheral speed
of the substrate 6 that is determined by the angular velocity and
the radius of the substrate 6. It follows that, if the amount of
the first solution supplied to the substrate 6 is controlled in
accordance with the change in the angular velocity of the substrate
6 detected by the angular velocity detecting sensor 72, i.e., in
accordance with the change in the peripheral speed of the substrate
6, it is possible to diminish the difference in temperature between
the central portion and the peripheral portion of the substrate
6.
[0056] The supply amount of the first process solution is adjusted
by increasing the flow rates of both sulfuric acid and the hydrogen
peroxide solution without changing the ratio of sulfuric acid to
the hydrogen peroxide solution that are controlled by the first
flow rate control valve 62 and the second flow rate control valve
64.
[0057] A temperature sensor 73 for detecting the temperature of the
mixed process solution is arranged within the mixing chamber 52 of
the nozzle member 31. A signal of the temperature sensor 73
denoting the detected temperature is supplied to the control device
71. As a result, the degree of opening of each of the first and
second flow rate control valves 62 and 64 is controlled so as to
change the mixing ratio of sulfuric acid to the hydrogen peroxide
solution, thereby changing the temperature of the first process
solution. In other words, the temperature of the substrate 6 can be
controlled by the control device 71 on the basis of the detection
signal of the angular velocity detecting sensor 72 and the
detection signal of the temperature sensor 73.
[0058] The opening-closing valves 61, 63, 65 mounted to the first,
second and third supply pipes 54, 55, 56, respectively, are
selectively opened or closed by the control device 71. To be more
specific, when the first process solution is supplied, the control
device 71 permits the first opening-closing valve 61 and the second
opening-closing valve 63 to be opened. On the other hand, when the
second process solution is supplied, the control device 71 permits
the third opening-closing valve 65 to be opened.
[0059] Suppose a resist film or an organic film formed on the
substrate 6 is unlikely to be dissolved in a solvent. In this case,
the resist film or the organic film is removed by the processing
apparatus of the construction described above as follows. In the
first step, the substrate 6 is disposed on the spin chuck 5 and,
then, the spin chuck 5 is rotated. At the same time, the nozzle
member 31 is positioned above the central portion of the substrate
6.
[0060] When the processing of the substrate 6 is started by
operating the control device 71 under this condition, the first and
second opening-closing valves 61 and 63 are opened. At the same
time, the first and second flow rate control valves 62 and 64 are
opened with an opening degree conforming with the angular velocity
of the substrate 6. As a result, sulfuric acid and a hydrogen
peroxide solution are supplied at predetermined rates through the
first supply pipe 54 and the second supply pipe 55, respectively,
into the mixing chamber 52 of the nozzle member 31.
[0061] The sulfuric acid and hydrogen peroxide solution flow into
the mixing chamber 52 and collide against the two baffle members
621, 62b arranged within the spurting hole 53 and collectively
constituting the mixing mechanism 60 so as to form an eddy current.
As a result, the sulfuric acid and hydrogen peroxide solution are
sufficiently mixed to form the first process solution, which is
spurted from the spurting hole 53 toward the central portion of the
substrate 6.
[0062] The first solution prepared by mixing the sulfuric acid and
hydrogen peroxide solution generates heat of solution. As a result,
the temperature of the first process solution is elevated, and the
first process solution is caused to flow centrifugally from the
central portion toward the peripheral portion of the substrate 6.
It follows that the resist pattern or the organic film formed on
the substrate 6 is decomposed by the first process solution.
[0063] In performing the decomposition treatment, the substrate 6
is heated to a predetermined temperature by the heat of solution
generated from the first process solution. As a result, the
decomposition treatment of, for example, the resist pattern formed
on the substrate 6 is promoted so as to further improve the effect
of the processing. To be more specific, since the substrate 6 is
processed by utilizing the heat of solution of the first process
solution, it is unnecessary to heat the substrate 6 and the process
solution to high temperatures, making it possible to carry out
easily the heat treatment of the substrate 6.
[0064] The sulfuric acid and the hydrogen peroxide solution are
mixed within the mixing chamber 52 formed within the nozzle member
31 to form the first process solution. In addition, the first
process solution is caused to form an eddy current by the two
baffle members 62a, 62 collectively forming the mixing mechanism 60
within the spurting hole 53 so as to achieve a satisfactory mixing
of the sulfuric acid and the hydrogen peroxide solution. This makes
it unnecessary to mix in advance the sulfuric acid the hydrogen
peroxide solution, with the result that the construction of the
entire apparatus can be simplified.
[0065] The first and second flow rate control valves 62 and 64 are
mounted, respectively, to the first and second supply pipes 54 and
55 for supplying sulfuric acid and hydrogen peroxide solution to
the nozzle member 31. Also, the degree of opening of each of the
first and second flow rate control valves 62 and 64 is controlled
on the basis of the peripheral speed of the substrate 6 and the
temperature of the first process solution within the mixing chamber
52. To be more specific, the supply rate of the first process
solution is controlled in proportion to the change in the
peripheral speed of the rotating substrate 6, and the ratio of
sulfuric acid contained in the first process solution is controlled
on the basis of the temperature of the first process solution
within the mixing chamber 53. As a result, the substrate 6 is
heated to a substantially uniform temperature by the first process
solution having a predetermined temperature, making it possible to
process the substrate 6 without fail.
[0066] The nozzle member 31 is mounted to the horizontal arm 33 of
the rotating mechanism 32. Therefore, the first process solution
can be spurted from the nozzle member 31 mounted to the tip portion
33a of the horizontal arm 33 toward the substrate 6 while
reciprocating the horizontal arm 33 in the radial direction of the
substrate 6.
[0067] If the horizontal arm 33 is driven, the first process
solution is uniformly supplied from the nozzle member 31 to the
substrate 6, making it possible to process the entire surface of
the substrate 6 more uniformly.
[0068] Where the nozzle member 31 is reciprocated in the radial
direction of the substrate 6, the temperature of the first process
solution on the substrate 6 is scarcely changed by the difference
in the peripheral speed between the central portion and the
peripheral portion of the substrate 6. Therefore, it suffices for
the control device 71 to control only the mixing ratio of sulfuric
acid to the hydrogen peroxide solution depending on the temperature
of the first process solution within the mixing chamber 52, which
is detected by the temperature sensor 73.
[0069] Incidentally, it is possible to supply a predetermined
amount of the first process solution intermittently in place of
supplying the first process solution continuously. where the first
process solution is supplied intermittently, the first process
solution is newly supplied to the substrate 6 after the reaction
such as the decomposing reaction of the first process solution
supplied first has sufficiently proceeded. Therefore, the
efficiency of use of the first process solution is improved, making
it possible to decrease the amount of the first process solution
used.
[0070] FIG. 4 is a time chart showing the timing of supplying
sulfuric acid, a hydrogen peroxide solution and a pure water. At
the process starting time To, sulfuric acid and the hydrogen
peroxide solution, which collectively form the first process
solution, are supplied to the substrate 6. After the processing
with the first process solution is continued until time T1, the
first opening-closing valve 61 is closed so as to stop supply of
sulfuric acid, and the hydrogen peroxide solution alone is supplied
until time T2. Since the hydrogen peroxide solution alone is
supplied during the period between time T1 and time T2, the
sulfuric acid within the nozzle member 31 and attached to the
substrate 6 and the cup body 1 is diluted with the hydrogen
peroxide solution into a low concentration.
[0071] After the hydrogen peroxide solution is supplied until time
T2, the second opening-closing valve 63 is closed, and the third
valve 65 mounted to the third supply pipe 56 is opened so as to
supply a second process solution consisting of a rinsing solution
(pure water) from the nozzle member 31 to the substrate 6. The
rinsing solution is continued to be supplied until time T3 so as to
permit the substrate 6 to be rinsed with the rinsing solution. It
should be noted that, when the substrate 6 is rinsed with the
second process solution, the sulfuric acid contained in the first
process solution and remaining on the substrate 6 and within the
cup body 1 is sufficiently diluted with the hydrogen peroxide
solution into a low concentration. Therefore, even if the second
process solution (pure water) is mixed with the sulfuric acid
contained in the first process solution and attached to the
substrate 6 and the cup body 1, a dissolving reaction (chemical
reaction) between the pure water and the sulfuric acid does not
take place because the sulfuric acid concentration in the first
process solution is sufficiently low. In other words, since a
dissolving reaction between the pure water and sulfuric acid does
not take place, the substrate 6 is not contaminated by the mist
generation and scattering of sulfuric acid.
[0072] When the substrate 6 is rinsed with the second process
solution until time T3, the supply of the second process solution
is stopped and the substrate 6 is rotated at a high speed so as to
centrifugally remove the rinsing solution attached to the substrate
6 and, thus, to dry the substrate 6, thereby finishing a series of
the processing.
[0073] Incidentally, as denoted by broken lines in FIG. 4, it is
possible to operate the first flow rate control valve 62 and the
second flow rate control valve 64 in a manner to stop gradually the
supply of sulfuric acid and the hydrogen peroxide solution.
[0074] In the first embodiment described above, a glass substrate
is used as the substrate 6. Alternatively, it is also possible to
use a semiconductor wafer or a substrate for a photo mask as the
substrate 6, as far as a resist pattern or an organic film is
removed by utilizing the decomposing reaction.
[0075] Also, in the first embodiment described above, the two
baffle members 62a, 62b are arranged within the spurting hole 53 as
a mixing means of the process solution. Alternatively, it is also
possible to arrange two baffle members 62a, 62b, which are
substantially semicircular, within the mixing chamber 52 in a
manner to be deviant from each other by 180.degree. in the
circumferential direction, as shown in FIG. 5 (second
embodiment).
[0076] FIG. 6 shows a third embodiment of the present invention. In
this embodiment, the nozzle member 31 is divided into the nozzle
body 51 having the mixing chamber 52 formed therein and a nozzle
outlet body 75 forming the spurting hole 53. The nozzle outlet body
75 forming the spurting hole 53. The nozzle outlet body 75 is
connected liquid light to the nozzle body 51 so as to form the
nozzle member 31. Further, the two semicircular baffle members 62a,
62b are formed within the nozzle outlet body 75 so as to form the
mixing mechanism 60 for mixing the sulfuric acid and the hydrogen
peroxide solution collectively forming the first process
solution.
[0077] Where the nozzle member 31 is divided into the nozzle body
51 and the nozzle outlet body 75 as shown in FIG. 6, the baffle
members 62a, 62b can be mounted easily within the nozzle outlet
body 75. Incidentally, it is possible to form the baffle members
62a, 62b integral with the nozzle outlet body 75, or to mount the
baffle members 62a, 62b formed separately within the nozzle outlet
body 75.
[0078] In the third embodiment described above, it is possible to
arrange the baffle members 62a, 62b within the mixing chamber 52 of
the nozzle body 51, though the particular arrangement is not shown
in the drawing.
[0079] In the third embodiment, the shape and the number of baffle
members 62a, 62b of the mixing mechanism 61 are not particularly
limited, as far as the process solution supplied to the mixing
chamber 52 is sufficiently mixed.
[0080] 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.
* * * * *