U.S. patent application number 12/015029 was filed with the patent office on 2008-07-24 for substrate treatment method, coating film removing apparatus, and substrate treatment system.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. Invention is credited to Junichi Kitano, Hideharu Kyouda, Osamu Miyahara, Kenji TSUTSUMI.
Application Number | 20080176002 12/015029 |
Document ID | / |
Family ID | 39641516 |
Filed Date | 2008-07-24 |
United States Patent
Application |
20080176002 |
Kind Code |
A1 |
TSUTSUMI; Kenji ; et
al. |
July 24, 2008 |
SUBSTRATE TREATMENT METHOD, COATING FILM REMOVING APPARATUS, AND
SUBSTRATE TREATMENT SYSTEM
Abstract
According to the present invention, during the photolithography
processing of a substrate, exposure processing is performed
immediately after removal of a coating film on the rear surface of
the substrate, and a coating film is formed on the rear surface of
the substrate immediately after the exposure processing.
Thereafter, etching treatment and so on are performed, and a series
of these treatment and processing steps are performed a
predetermined number of times. The coating film has been formed on
the rear surface of the substrate at the time for the etching
treatment, so that even if the coating film gets minute scratches,
the rear surface of the substrate itself is protected by the
coating film and thus never scratched. Further, since the coating
film on the rear surface of the substrate is removed immediately
before the exposure processing, the rear surface of the substrate
can be flat for the exposure processing.
Inventors: |
TSUTSUMI; Kenji; (Koshi-shi,
JP) ; Kitano; Junichi; (Koshi-shi, JP) ;
Miyahara; Osamu; (Koshi-shi, JP) ; Kyouda;
Hideharu; (Koshi-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
TOKYO ELECTRON LIMITED
Tokyo
JP
|
Family ID: |
39641516 |
Appl. No.: |
12/015029 |
Filed: |
January 16, 2008 |
Current U.S.
Class: |
427/496 ;
156/345.23; 257/E21.231; 427/372.2; 427/508 |
Current CPC
Class: |
H01L 21/6715 20130101;
H01L 21/308 20130101; G03F 7/70916 20130101; H01L 21/68707
20130101; H01L 21/67225 20130101; G03F 7/707 20130101; C23C 26/00
20130101; G03F 1/80 20130101; H01L 21/67178 20130101; H01L 21/67745
20130101; H01L 21/67742 20130101; H01L 21/6708 20130101 |
Class at
Publication: |
427/496 ;
427/508; 156/345.23; 427/372.2 |
International
Class: |
C23C 26/00 20060101
C23C026/00; H01L 21/306 20060101 H01L021/306 |
Foreign Application Data
Date |
Code |
Application Number |
Jan 22, 2007 |
JP |
2007-011262 |
Claims
1. A substrate treatment method of performing at least
photolithography processing and etching treatment for a substrate
in this order a plurality of times, comprising the steps of:
forming a coating film on a rear surface of the substrate after
exposure processing in the photolithography processing is
performed; and removing the coating film between the formation of
the coating film and performance of next exposure processing.
2. The substrate treatment method as set forth in claim 1, wherein
said step of forming a coating film comprises the steps of:
inverting the substrate to direct the rear surface of the substrate
upward; applying a coating solution to the rear surface of the
substrate; and curing the coating solution applied on the rear
surface of the substrate.
3. The substrate treatment method as set forth in claim 1, wherein
said step of removing the coating film comprises the step of
supplying a removing solution to the coating film.
4. The substrate treatment method as set forth in claim 3, wherein
said step of removing the coating film comprises the step of,
before supplying the removing solution to the coating film,
inverting the substrate to direct the rear surface of the substrate
upward.
5. The substrate treatment method as set forth in claim 1, further
comprising the step of: immediately before said step of forming a
coating film, cleaning the rear surface of the substrate.
6. The substrate treatment method as set forth in claim 2, wherein
the coating solution applied on the rear surface of the substrate
is cured by being heated.
7. The substrate treatment method as set forth in claim 2, wherein
the coating solution applied on the rear surface of the substrate
is cured by being irradiated with ultraviolet rays or electron
beams.
8. A coating film removing apparatus for removing a coating film
formed on a rear surface of a substrate, comprising: a transfer arm
transferring the substrate; a turning mechanism supporting said
transfer arm and turning said transfer arm around a horizontal
axis; a raising and lowering mechanism supporting said turning
mechanism and raising and lowering said turning mechanism; a
transfer mechanism supporting said raising and lowering mechanism
and transferring said raising and lowering mechanism in the
horizontal direction; a substrate holding unit horizontally holding
the substrate with the rear surface of the substrate directed
upward; and a removing solution supply nozzle supplying a removing
solution for the coating film to the rear surface of the substrate
held by said substrate holding unit.
9. The coating film removing apparatus as set forth in claim 8,
wherein a rotating mechanism rotating said substrate holding unit
around a vertical axis is provided below said substrate holding
unit.
10. The coating film removing apparatus as set forth in claim 8,
wherein said removing solution supply nozzle is a nozzle having a
discharge port in a slit form extending in a direction of a width
of the substrate.
11. A substrate treatment system including a coating film removing
apparatus for removing a coating film formed on a rear surface of a
substrate and an exposure processing apparatus for performing
exposure processing on the substrate, said coating film removing
apparatus comprising: a transfer arm transferring the substrate; a
turning mechanism supporting said transfer arm and turning said
transfer arm around a horizontal axis; a raising and lowering
mechanism supporting said turning mechanism and raising and
lowering said turning mechanism; a transfer mechanism supporting
said raising and lowering mechanism and transferring said raising
and lowering mechanism in the horizontal direction; a substrate
holding unit horizontally holding the substrate with the rear
surface of the substrate directed upward; and a removing solution
supply nozzle supplying a removing solution for the coating film to
the rear surface of the substrate held by said substrate holding
unit.
12. The substrate treatment system as set forth in claim 11,
further comprising: a coating film forming apparatus for forming
the coating film on the rear surface of the substrate.
Description
BACKGROUND OF THE INVENTION
[0001] 1. Field of the Invention
[0002] The present invention relates to a method of treating a
substrate, for example, a semiconductor wafer or the like, a
coating film removing apparatus, and a substrate treatment
system.
[0003] 2. Description of the Related Art
[0004] In photolithography processing in a process of manufacturing
a semiconductor device, for example, resist coating treatment of
applying a resist solution above a semiconductor wafer
(hereinafter, referred to as a "wafer") to form a resist film,
exposure processing of exposing the resist film to light under a
predetermined pattern, and developing treatment of developing the
exposed resist film and so on are performed in sequence, to form a
predetermined resist pattern above the wafer. Etching treatment of
the wafer is performed using this resist pattern as a mask, and
stripping processing of the resist film and cleaning of the wafer
are then performed to form a predetermined pattern on the wafer.
The process of forming a predetermined pattern in a predetermined
layer is generally repeatedly performed 20 to 30 times to
manufacture a semiconductor device.
[0005] Out of these treatments and processing, the above-described
exposure processing is performed, for example, by applying ArF
laser, KrF laser, or the like to the resist film on the wafer with
the rear surface of the wafer being suction-held by a chuck in the
apparatus for performing the exposure processing. If, for example,
contaminants adhere to the rear surface of the wafer when the
exposure processing is performed, the wafer is not horizontally
held by the chuck, thus causing defocus during the exposure
processing. Accordingly, it is necessary that the wafer is
horizontally held by the chuck, that is, the rear surface of the
wafer sucked by the chuck is flat, in order to appropriately
perform the exposure processing.
[0006] Hence, a scribing apparatus including a transfer arm for
inverting the front and rear surfaces of the wafer, a freely
rotatable spin chuck for holding the wafer, and a scribing brush
for cleaning the front and rear surfaces of the wafer held by the
spin chuck has been conventionally proposed as an apparatus for
removing the contaminants on the rear surface of the wafer.
Conventionally, before performance of the exposure processing for
the wafer, the scribing apparatus is used to first direct the rear
surface of the wafer upward by means of the transfer arm and hold
the wafer in this state by means of the spin chuck. The scribing
brush is brought into contact with the rear surface of the wafer
while rotating the spin chuck is rotating, thereby removing the
contaminants adhering to the rear surface of the wafer (Japanese
Patent Publication Laid-open No. Hei 3-52226).
[0007] However, even if the contaminants on the rear surface of the
wafer are removed, minute scratches may be generated on the rear
surface of the wafer during various kinds of treatments and
processing in the process of manufacturing the wafer to cause
projections and depressions on the rear surface of the wafer.
Especially when the etching treatment is performed, the rear
surface of the wafer is likely to get minute scratches if the
surface temperatures of the wafer and the electrostatic chuck are
increased during the etching treatment due to the difference in
coefficient of thermal expansion between the wafer and the
electrostatic chuck holding the wafer. Due to such minute scratches
on the rear surface of the wafer, the wafer is not horizontally
held during the exposure processing, thus causing defocus.
SUMMARY OF THE INVENTION
[0008] The present invention has been developed in consideration of
the above points, and its object is to planarize the rear surface
of a substrate before exposure processing in order to appropriately
perform the exposure processing with the substrate being
horizontally held.
[0009] To attain the above object, in the present invention, a
substrate treatment method of performing at least photolithography
processing and etching treatment for a substrate in this order a
plurality of times, includes the steps of forming a coating film on
a rear surface of the substrate after exposure processing in the
photolithography processing is performed; and removing the coating
film between the formation of the coating film and performance of
next exposure processing.
[0010] According to the substrate treatment method of the present
invention, after performance of exposure processing, the coating
film is formed on the rear surface of the substrate, for example,
immediately after the exposure processing, so that even if the
coating film on the rear surface of the substrate gets minute
scratches, for example, during the etching treatment performed
after the photolithography processing and the transfer of the
substrate, the rear surface of the substrate itself is protected by
the coating film and thus never scratched. Since the coating film
on the rear surface of the substrate is then removed before next
exposure processing is performed, the rear surface of the substrate
can be flat without projections and depressions in the exposure
processing performed after the removal of the coating film.
Accordingly, the substrate can be horizontally held during the
exposure processing, so that the exposure processing can be
appropriately performed. In this case, as a matter of course, the
step of forming the coating film on the rear surface of the
substrate may be performed before the photolithography processing
for the first time is performed, and the step of removing the
coating film formed before the photolithography processing for the
first time may be performed before exposure processing in the
photolithography processing for the first time. Thereby, even if
the coating film formed on the rear surface of the substrate gets
minute scratches during performance of treatment steps prior to the
exposure processing performed in the photolithography processing
for the first time, for example, the step of forming a resist film,
and during the transfer of the substrate, the rear surface of the
substrate itself is protected by the coating film and thus never
scratched. In addition, since the coating film is removed before
the exposure processing in photolithography processing for the
first time is performed, for example, immediately before the
exposure processing, the rear surface of the substrate can be flat
for the exposure processing.
[0011] The method may further include the step of, immediately
before the step of forming a coating film, cleaning the rear
surface of the substrate. This removes the contaminants on the rear
surface of the substrate immediately before a coating film is
formed on the rear surface of the substrate, thereby ensuring that
the coating film is planarized more reliably.
[0012] According to another aspect, the present invention is a
coating film removing apparatus for removing a coating film formed
on a rear surface of a substrate including a transfer arm
transferring the substrate; a turning mechanism supporting the
transfer arm and turning the transfer arm around a horizontal axis;
a raising and lowering mechanism supporting the turning mechanism
and raising and lowering the turning mechanism; a transfer
mechanism supporting the raising and lowering mechanism and
transferring the raising and lowering mechanism in the horizontal
direction; a substrate holding unit horizontally holding the
substrate with the rear surface of the substrate directed upward;
and a removing solution supply nozzle supplying a removing solution
for the coating film to the rear surface of the substrate held by
the substrate holding unit.
[0013] According to the coating film removing apparatus of the
present invention, the coating film on the rear surface of the
substrate can be removed by directing the rear surface of the
substrate upward by means of the transfer arm and the turning
mechanism and supplying the removing solution from the removing
solution supply nozzle to the rear surface of the substrate.
[0014] A rotating mechanism may be provided below the substrate
holding unit for rotating the substrate holding unit around a
vertical axis. The rotating mechanism rotates the substrate held by
the substrate holding unit, thereby allowing the removing solution
supplied on the coating film on the rear surface of the substrate
to uniformly spread.
[0015] The coating film removing apparatus may be located in the
same substrate treatment system with the exposure processing
apparatus for performing exposure processing on the substrate. A
coating film forming apparatus for forming the coating film on the
rear surface of the substrate may further be located in the
substrate treatment system. This ensures that the removal of the
coating film on the rear surface of the substrate, the exposure
processing of the substrate, and the formation of the coating film
on the rear surface of the substrate can be performed in line, thus
smoothly performing a series of treatment and processing of the
substrate.
[0016] According to the present invention, the rear surface of the
substrate can be planarized before exposure processing, thus
ensuring that preferable exposure processing can be performed.
BRIEF DESCRIPTION OF THE DRAWINGS
[0017] FIG. 1 is a plan view schematically showing the outline of a
configuration of a coating and developing treatment system
incorporating a coating film removing apparatus according to an
embodiment;
[0018] FIG. 2 is a front view of the coating and developing
treatment system according to the embodiment;
[0019] FIG. 3 is a rear view of the coating and developing
treatment system according to the embodiment;
[0020] FIG. 4 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film removing
apparatus;
[0021] FIG. 5 is a plan view schematically showing the outline of a
configuration of the coating film removing apparatus;
[0022] FIG. 6 is a perspective view of a transfer arm, a turning
mechanism and a transfer mechanism;
[0023] FIG. 7 is a side view of the transfer arm holding a
wafer;
[0024] FIG. 8 is a longitudinal sectional view of a spin chuck;
[0025] FIG. 9 is a longitudinal sectional view showing a structure
of a support pin of the spin chuck;
[0026] FIG. 10 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film forming
apparatus;
[0027] FIG. 11 is a plan view schematically showing the outline of
a configuration of the coating film forming apparatus;
[0028] FIG. 12 is a flow showing a procedure of wafer
treatment;
[0029] FIG. 13 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film forming
apparatus;
[0030] FIG. 14 is a plan view schematically showing the outline of
a configuration of the coating film forming apparatus;
[0031] FIG. 15 is a perspective view of a coating nozzle having a
discharge port in a slit form;
[0032] FIG. 16 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film removing
apparatus;
[0033] FIG. 17 is a plan view schematically showing the outline of
a configuration of the coating film removing apparatus;
[0034] FIG. 18 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film removing
apparatus;
[0035] FIG. 19 is a longitudinal sectional view a spin chuck;
[0036] FIG. 20 is a longitudinal sectional view schematically
showing the outline of a configuration of a coating film removing
apparatus;
[0037] FIG. 21 is a plan view schematically showing the outline of
a configuration of a coating film removing system;
[0038] FIG. 22 is a front view of the coating film removing
system;
[0039] FIG. 23 is a flowchart showing a time to remove the coating
film by the coating film removing system, and a time to form the
coating film by the coating film forming system; and
[0040] FIG. 24 is a plan view schematically showing the outline of
a configuration of a coating film forming system.
DETAILED DESCRIPTION OF THE INVENTION
[0041] Hereinafter, a preferred embodiment of the present invention
will be described. FIG. 1 is a plan view showing the outline of a
configuration of a coating and developing treatment system 1 as a
substrate treatment system incorporating a coating film removing
apparatus 200 according to the embodiment, FIG. 2 is a front view
of the coating and developing treatment system 1, and FIG. 3 is a
rear view of the coating and developing treatment system 1.
[0042] The coating and developing treatment system 1 has, as shown
in FIG. 1, a configuration in which, for example, a cassette
station 2 for transferring 25 wafers W per cassette as a unit
from/to the outside into/from the coating and developing treatment
system 1 and transferring the wafers W into/out of a cassette C; a
processing station 3 including a plurality of various kinds of
processing and treatment units, which are multi-tiered, for
performing predetermined processing or treatment in a manner of
single wafer processing in the photolithography process; and an
interface section 4 for delivering the wafers W to/from an exposure
processing apparatus 8 provided adjacent to the processing station
3, are integrally connected.
[0043] In the cassette station 2, a cassette mounting table 5 is
provided and configured such that a plurality of cassettes C can be
mounted thereon in a line in an X-direction (a top-to-bottom
direction in FIG. 1). In the cassette station 2, a wafer transfer
body 7 is provided which is movable in the X-direction on a
transfer path 6. The wafer transfer body 7 is also movable in a
wafer-arrangement direction of the wafers W housed in the cassette
C (a Z-direction; the vertical direction), and thus can selectively
access the wafer W in each of the cassettes C arranged in the
X-direction.
[0044] The wafer transfer body 7 is rotatable in a
.theta.-direction around a Z-axis, and can access a temperature
regulating unit 60 for regulating the temperature of the wafer W
and a transition unit 61 for passing the wafer W included in a
later-described third processing unit group G3 on the processing
station 3 side.
[0045] The processing station 3 adjacent to the cassette station 2
includes, for example, five processing unit groups G1 to G5 in each
of which a plurality of processing and treatment units are
multi-tiered. On the side of the negative direction in the
X-direction (the downward direction in FIG. 1) in the processing
station 3, the first processing unit group G1 and the second
processing unit group G2 are placed in order from the cassette
station 2 side. On the side of the positive direction in the
X-direction (the upward direction in FIG. 1) in the processing
station 3, the third processing unit group G3, the fourth
processing unit group G4, and the fifth processing unit group G5
are placed in order from the cassette station 2 side. Between the
third processing unit group G3 and the fourth processing unit group
G4, a first transfer unit A1 is provided, and a first transfer arm
10 that supports and transfers the wafer W is provided inside the
first transfer unit A1. The first transfer arm 10 can selectively
access the processing and treatment units in the first processing
unit group G1, the third processing unit group G3, and the fourth
processing unit group G4 and transfer the wafer W to them. Between
the fourth processing unit group G4 and the fifth processing unit
group G5, a second transfer unit A2 is provided, and a second
transfer arm 11 that supports and transfers the wafer W is provided
inside the second transfer unit A2. The second transfer arm 11 can
selectively access the processing and treatment units in the second
processing unit group G2, the fourth processing unit group G4, and
the fifth processing unit group G5 and transfer the wafer W to
them.
[0046] In the first processing unit group G1, as shown in FIG. 2,
solution treatment units each for supplying a predetermined liquid
to the wafer W to perform treatment, for example, resist coating
units 20, 21, and 22 each for applying a resist solution to the
wafer W, and bottom coating unit 23 and 24 each for forming an
anti-reflection film that prevents reflection of light at the time
of exposure processing, are five-tiered in order from the bottom.
In the second processing unit group G2, solution treatment units,
for example, developing treatment units 30 to 34 each for supplying
a developing solution to the wafer W to develop it are five-tiered
in order from the bottom. Further, chemical chambers 40 and 41 for
supplying various kinds of treatment solutions to the solution
treatment units in the processing unit groups G1 and G2 are
provided at the lowermost tiers of the first processing unit group
GI and the second processing unit group G2, respectively.
[0047] As shown in FIG. 3, in the third processing unit group G3,
for example, the temperature regulating unit 60, the transition
unit 61, high-precision temperature regulating units 62 to 64 each
for regulating the temperature of the wafer W under a high
precision temperature control, and high-temperature thermal
processing units 65 to 68 each for heat-processing the wafer W at a
high temperature, are nine-tiered in order from the bottom.
[0048] In the fourth processing unit group G4, for example, a
high-precision temperature regulating unit 70, pre-baking units 71
to 74 each for heat-processing the wafer W after resist coating
treatment, and post-baking units 75 to 79 each for heat-processing
the wafer W after developing treatment, are ten-tiered in order
from the bottom.
[0049] In the fifth processing unit group G5, a plurality of
thermal processing units each for thermally processing the wafer W,
for example, high-precision temperature regulating units 80 to 83,
and post-exposure baking units 84 to 89, are ten-tiered in order
from the bottom.
[0050] As shown in FIG. 1, on the positive direction side in the
X-direction to the first transfer unit A1, a plurality of
processing and treatment units are arranged, for example, adhesion
units 90 and 91 each for performing hydrophobic treatment on the
wafer W and heating units 92 and 93 each for heating the wafer W
being four-tiered in order from the bottom as shown in FIG. 3. As
shown in FIG. 1, on the positive direction side in the X-direction
to the second transfer unit A2, for example, an edge exposure unit
94 is disposed which selectively exposes only the edge portion of
the wafer W to light.
[0051] In the interface section 4, for example, a wafer transfer
body 101 moving on a transfer path 100 extending in the
X-direction, a buffer cassette 102, and a coating film processing
unit group G6 are provided as shown in FIG. 1. The buffer cassette
102 is disposed on the positive direction side in the X-direction
(the upward direction in FIG. 1) in the interface section 4, and
the coating film processing unit group G6 is disposed on the
negative direction side in the X-direction (the downward direction
in FIG. 1). The wafer transfer body 101 is movable in the
Z-direction and also rotatable in the .theta.-direction, and thus
can access the exposure processing apparatus 8 adjacent to the
interface section 4, the buffer cassette 102, the coating film
processing unit group G6, and the fifth processing unit group G5
and transfer the wafer W to them.
[0052] As shown in FIG. 2, for example, coating film forming
apparatuses 300 at two tiers each for forming a coating film on the
rear surface of the wafer W and coating film removing apparatuses
200 at two tiers each for removing the coating film on the rear
surface of the wafer W according to the embodiment are stacked in
order from the bottom in the coating film processing unit group
G6.
[0053] Next, the configuration of the above-described coating film
removing apparatus 200 will be described based on FIG. 4. The
coating film removing apparatus 200 has a treatment container 250
whose inside can be closed. On one side surface of the treatment
container 250, a transfer-in/out port 251 for the wafer W is
provided in a surface facing a transfer-in region for the wafer
transfer body 101 being a transfer means for the wafer W, and an
opening/closing shutter 252 is provided at the transfer-in/out port
251.
[0054] Inside the treatment container 250, as shown in FIG. 5, a
wafer delivery table 240 for mounting the wafer W transferred
thereinto through the transfer-in/out port 251. On the wafer
delivery table 240, for example, three support pints 240a for
supporting the wafer W are provided.
[0055] Inside the treatment container 250, a transfer arm 260 is
provided which transfers the wafer W between the wafer delivery
table 240 and a later-described spin chuck 220. The transfer 260
has a pair of chuck portions 261 capable of approaching to and
separating from each other as shown in FIG. 6. The chuck portion
261 has a flame portion 261 a formed in a quarter ring, and an arm
portion 261b integrally formed with the flame portion 261a for
supporting the flame portion 261a. The flame portions 261a are
provided with respective wafer clamp portions 262, and tapered
grooves 262a are formed in the side surfaces of the wafer clamp
portions 262 as shown in FIG. 7. The pair of separated chuck
portions 261 approach to each other, whereby peripheral portions of
the wafer W are inserted into the tapered grooves 262a so that the
wafer W is supported.
[0056] The transfer arm 260 is supported by a turning mechanism 263
as shown in FIG. 6. The turning mechanism 263 has a drive unit (not
shown) such as a motor or the like therein, and allows the transfer
arm 260 to turn around the horizontal axis (around the X-axis) and
expand and contract in the horizontal direction (the X-direction).
In other words, the front and rear surfaces of the wafer W held by
the transfer arm 260 can be inverted, and the wafer W can be moved
in the horizontal direction (the X-direction). A shaft 264 is
provided on the lower surface of the turning mechanism 263, and the
lower end of the shaft 264 is connected to a raising and lowering
mechanism 265. The raising and lowering mechanism 265 has a drive
unit (not shown) such as a motor or the like therein, and can raise
and lower the turning mechanism 263 and the transfer arm 260. The
raising and lowering mechanism 265 is supported by a transfer
mechanism 266, and the transfer mechanism 266 allows the raising
and lowering mechanism 265, the turning mechanism 263, and the
transfer arm 260 to move along a guide rail 267 provided along the
longitudinal direction (the Y-direction) of the treatment container
250 as shown in FIG. 5. In other words, the wafer W supported by
the transfer arm 260 can be transferred in the treatment container
250.
[0057] Inside the treatment container 250, a spin chuck 220 as a
substrate holding unit is provided which horizontally holds the
wafer W with the rear surface of the wafer W directed upward as
shown in FIG. 4. The spin chuck 220 can rotate around the vertical
axis and raise and lower by means of a rotating mechanism 221
including a motor and the like. On the upper surface of the spin
chuck 220, for example, eight holding pins 222 for holding the
peripheral portion of the wafer W are provided along the peripheral
portion of the wafer W as shown in FIG. 8. The holding pin 222 has
a horizontal holding surface 222a for directly holding the wafer W
and a vertical wall 222b parallel to the peripheral side edge of
the wafer W as shown in FIG. 9, and the top portion of the vertical
wall 222b has a height to protrude from the upper surface of the
wafer W when the wafer W is held on the holding surface 222a. At
the central portion of the upper surface of the spin chuck 220, a
recessed portion 224 is formed downward as shown in FIG. 8, so that
a space 223 is formed between the recessed portion 224 and the
wafer W.
[0058] At the central portion of the upper surface of the spin
chuck 220, a gas supply port 224a is formed which jets an inert
gas, for example, nitrogen gas toward the space 223, and a gas
supply pipe 225 penetrating through the spin chuck 220 is connected
to the gas supply port 224a. The inert gas jetted from the gas
supply port 224a toward the space 223 flows from the side of the
lower surface of the wafer W, then around the peripheral side edge,
to the upper surface. Then, the pressure of the inert gas flowing
around to the side of the upper surface of the wafer W presses and
fixes the wafer W onto the holding pins 222. For this technique,
the publicly known technique described in JP H3-52226 can be
employed.
[0059] Around the spin chuck 220, a cup body 226 is provided as
shown in FIG. 4. The cup body 226 has an opening portion formed in
its upper face which is larger than the wafer W and the spin chuck
220 to allow the spin chuck 220 holding the wafer W thereon to rise
and lower therethrough. The bottom portion of the cup body 226 is
formed with drain ports 227 for draining a coating solution or a
rinse solution dropping out of the top of the wafer W, and drain
pipes 228 are connected to the drain ports 227.
[0060] Above the spin chuck 220, a removing solution supply nozzle
230 is located for supplying the removing solution for removing the
coating film onto the central portion of the rear surface of the
wafer W as shown in FIG. 4. The removing solution supply nozzle 230
is connected to a removing solution supply source 232 via a
removing solution supply pipe 231. The removing solution supply
pipe 231 is provided with a supply controller 233 including a
valve, a flow control unit, and so on. The removing solution
supplied from the removing solution supply source 232 is
selectively used depending on the kind of the coating film formed
on the rear surface of the wafer W, so that, for example, when the
coating film is an SOG (Spin On Glass) film, a treatment solution
such as hydrofluoric acid is used as the removing solution.
Besides, when the coating film is, for example, a resist film of an
organic material, PGMEA or the like, or acetone-based or
ketone-based solvent is used as the removing solution.
[0061] The removing solution supply nozzle 230 is connected to a
moving mechanism 235 via an arm 234 as shown in FIG. 5. The arm 234
is configured such that it can be moved by the moving mechanism 235
along a guide rail 236 provided along the longitudinal direction
(the Y-direction) of the treatment container 250, from a waiting
region 237 provided outside on the side of one end of the cup body
226 (the right side in FIG. 5) toward the other end side and
vertically moved. The waiting region 237 is configured to be able
to accommodate the removing solution supply nozzle 230 and includes
a cleaning portion 237a which can clean the tip end portion of the
removing solution supply nozzle 230.
[0062] Above the spin chuck 220, a rinse nozzle 270 is located for
cleaning the rear surface of the wafer W after the coating film is
removed as shown in FIG. 4. The rinse nozzle 270 is connected to a
rinse solution supply source 272 via a rinse solution supply pipe
271. The rinse solution supply pipe 271 is provided with a supply
controller 273 including a valve, a flow control unit, and so on.
As the rinse solution supplied from the rinse solution supply
source 272, for example, pure water is used.
[0063] An arm 274 and a moving mechanism 275 connected to the rinse
nozzle 270 have the same configuration as those of the arm 234 and
the moving mechanism 235 as shown in FIG. 5. The moving mechanism
275 of the rinse nozzle 270 and the moving mechanism 235 of the
removing solution supply nozzle 230 share the guide rail 236. The
arm 274 of the rinse nozzle 270 is configured such that it can be
moved by the moving mechanism 275 along the guide rail 236, from a
waiting region 276 provided outside on the side of one end of the
cup body 226 (the left side in FIG. 5) toward the other end side
and vertically moved. The waiting region 276 is configured to be
able to accommodate the rinse nozzle 270 and includes a cleaning
portion 276a which can clean the tip end portion of the rinse
nozzle 270.
[0064] Next, the configuration of the above-described coating film
forming apparatus 300 will be described based on FIG. 10. The
coating film forming apparatus 300 has a treatment container 350
whose inside can be closed. On one side surface of the treatment
container 350, a transfer-in/out port 351 for the wafer W is
provided in a surface facing a transfer-in region for the wafer
transfer body 101 being a transfer means for the wafer W, and an
opening/closing shutter 352 is provided at the transfer-in/out port
351. Inside the treatment container 350, a partition member 353 is
provided that partitions the inside of the treatment container 350
into a first treatment chamber 311 and a second treatment chamber
312, and the insides of the first treatment chamber 311 and the
second treatment chamber 312 are closable, respectively. The
partition member 353 is formed with a passing port 354 through
which a later-described transfer arm 360, turning mechanism 363,
raising and lowering mechanism 365, and transfer mechanism 366 can
pass, and an opening and closing shutter 355 is provided at the
passing port 354.
[0065] Inside the first treatment chamber 311, a wafer delivery
table 340 is provided for mounting the wafer W transferred
thereinto through a transfer-in/out port 351 as shown in FIG. 11.
On the wafer delivery table 340, for example, three support pints
340a for supporting the wafer W are provided.
[0066] Inside the coating film forming apparatus 300, a transfer
arm 360 is provided which receives the wafer W from the wafer
delivery table 340 and transfers the wafer W between the first
treatment chamber 311 and the second treatment chamber 312. The
transfer arm 360 has the same configuration as that of the transfer
arm 260 in the coating film removing apparatus 200 and thus can
hold the wafer W.
[0067] The turning mechanism 363 for supporting the transfer arm
360, a shaft 364 connected to the lower surface of the turning
mechanism 363, the raising and lowering mechanism 365 connected to
the lower end portion of the shaft 364, and the transfer mechanism
366 for supporting the raising and lowering mechanism 365 have the
same configurations as those of the turning mechanism 263, the
shaft 264, the raising and lowering mechanism 265, and the transfer
mechanism 266 in the coating film removing apparatus 200, and thus
can invert the front and rear surfaces of the wafer W held by the
transfer arm 360, and move the wafer W in the horizontal direction
(the X-direction) and raise and lower the wafer W.
[0068] A guide rail 367 on which the transfer mechanism 366 moves
is provided along the longitudinal direction (the Y-direction) of
the treatment container 350 as shown in FIG. 11 to allow the wafer
W supported by the transfer arm 360 to be transferred between the
first treatment chamber 311 and the second treatment chamber
312.
[0069] Inside the first treatment chamber 311, a spin chuck 320 is
provided which horizontally holds the wafer W with the rear surface
of the wafer W directed upward as shown in FIG. 10. The spin chuck
320 has the same configuration as that of the spin chuck 220 in the
coating film removing apparatus 200 and can be rotated around the
vertical axis and raised and lowered by a rotating mechanism 321,
and the wafer W can be fixed to the spin chuck 320 with the rear
surface of the wafer W directed upward.
[0070] A cup body 326 provided around the spin chuck 320, drain
ports 327 provided in the bottom portion of the cup body 326, drain
pipes 328 connected to the drain ports 327 have the same
configurations as those of the cup body 226, the drain ports 227,
and the drain pipes 228 in the coating film removing apparatus
200.
[0071] Above the spin chuck 320, a coating nozzle 330 is located
for supplying a coating solution onto the central portion of the
rear surface of the wafer W. The coating nozzle 330 is connected to
a coating solution supply source 332 via a coating solution supply
pipe 331. The coating solution supply pipe 331 is provided with a
supply controller 333 including a valve, a flow control unit, and
so on. As the coating solution supplied from the coating solution
supply source 332, for example, SOG material, or a resist of an
organic material or the like is used.
[0072] The coating nozzle 330 is connected to a moving mechanism
335 via an arm 334 as shown in FIG. 11. The arm 334 is configured
such that it can be moved by the moving mechanism 335 along a guide
rail 336 provided along the Y-direction of the first treatment
chamber 311, from a waiting region 337 provided outside on the side
of one end of the cup body 326 (the right side in FIG. 11) toward
the other end side and vertically moved. The waiting region 337 is
configured to be able to accommodate the coating nozzle 330 and
includes a cleaning portion 337a which can clean the tip end
portion of the coating nozzle 330.
[0073] In an upper portion of the second treatment chamber 312, a
lamp heating unit 341 is provided which cures the coating solution
applied on the wafer W as shown in FIG. 10. The lamp heating unit
341 can cure the coating solution on the wafer W by heating the
wafer W.
[0074] The coating and developing treatment system 1 incorporating
the coating film removing apparatus 200 according to this
embodiment is configured as described above, and the
photolithography processing and various kinds of treatments
performed on the wafer W after completion of the photolithography
processing which are performed in this coating and developing
treatment system 1 will be described next. FIG. 12 is a flow
showing the procedure of the wafer treatment.
[0075] First of all, one wafer W is taken out of the cassette C on
the cassette mounting table 5 by the wafer transfer body 7 and
transferred to the temperature regulating unit 60 in the third
processing unit group G3. The wafer W transferred to the
temperature regulating unit 60 is temperature-regulated to a
predetermined temperature and is then transferred by the first
transfer arm 10 into bottom coating unit 23, where an
anti-reflection film is formed. The wafer W above which the
anti-reflection film has been formed is transferred by the first
transfer arm 10 to the heating unit 92, the high-temperature
thermal processing unit 65, and the high-precision temperature
regulating unit 70 in sequence so that predetermined processing is
performed in each of the units. Thereafter, the wafer W is
transferred to the resist coating unit 20.
[0076] After a resist film has been formed over the front surface
of the wafer W in the resist coating unit 20, the wafer W is
transferred by the first transfer arm 10 to the pre-baking unit 71
and subjected to heating processing and subsequently transferred by
the second transfer arm 11 to the edge exposure unit 94 and the
high-precision temperature regulating unit 83 in sequence so that
the wafer W is subjected to predetermined processing in each of the
units. Thereafter, the wafer W is transferred by the wafer transfer
body 101 in the interface section 4 to the exposure processing
apparatus 8. In the exposure processing apparatus 8, the rear
surface of the wafer W is suction-held, and the resist film above
the wafer W is exposed to light under a predetermined pattern (Step
S1 in FIG. 12). The wafer W for which exposure processing has been
finished is transferred by the wafer transfer body 101 to the
coating film forming apparatus 300 (Step S2 in FIG. 12).
[0077] The wafer W transferred into the treatment container 350
through its transfer-in/out port 351 is mounted on the wafer
delivery table 340 by the wafer transfer body 101. Then, the
turning mechanism 363 extends the transfer arm 360 to a position of
the wafer delivery table 340 so that the transfer arm 360 holds the
wafer W.
[0078] The turning mechanism 363 then turns and inverts the wafer W
held by the transfer arm 360 to direct the rear surface of the
wafer W upward. In this state, the transfer mechanism 366 moves the
wafer W to above the spin chuck 320. The spin chuck 320 is then
raised to pass the wafer W from the transfer arm 360 to the spin
chuck 320. The transfer arm 360 is retracted from above the spin
chuck 320 and the inert gas is jetted from the gas supply port 324
of the spin chuck 320, whereby the wafer W is horizontally held on
the spin chuck 320. The spin chuck 320 is then lowered to lower the
wafer W to a predetermined position.
[0079] Subsequently, the rotating mechanism 321 rotates the wafer
W, and the coating nozzle 330 is moved to above the central portion
of the wafer W. The coating solution is discharged from the coating
nozzle 330 to the central portion of the rear surface of the wafer
W. The discharged coating solution spreads over the rear surface of
the wafer W by the centrifugal force generated by rotation of the
wafer W. Thereafter, the coating nozzle 330 is moved from above the
central portion of the wafer W to the waiting region 337. Note that
the coating solution may be applied within a range where the rear
surface of the wafer W is sucked in the exposure processing
apparatus 8, and the coating solution may not be applied at the
peripheral portion of the rear surface of the wafer W.
[0080] After spread of the coating solution on the rear surface of
the wafer W, the wafer W on the spin chuck 320 is raised to a
predetermined position, and the transfer arm 360 is extended to
move to above the spin chuck 320. The wafer W is passed from the
spin chuck 320 to the transfer arm 360.
[0081] Next, the transfer mechanism 366 moves the wafer W into the
second treatment chamber 312. The turning mechanism 363, the
raising and lowering mechanism 365, and the transfer mechanism 366
adjust the position of the wafer W so that the wafer W is located
directly below the lamp heating unit 341 as shown by broken line
portions in FIG. 10 and FIG. 11. Then, with the wafer W being held
by the transfer arm 360, the lamp heating unit 341 heats the wafer
W to cure the coating solution on the rear surface of the wafer
W.
[0082] After formation of the coating film by curing the coating
solution on the rear surface of the wafer W, the transfer mechanism
366 moves again the wafer W into the first treatment chamber 311.
The turning mechanism 363 then turns and inverts the wafer W to
direct the front surface of the wafer W upward, and the wafer W is
passed from the transfer arm 360 to the wafer delivery table 340.
The wafer W is then transferred by the wafer transfer body 101 to
the outside of the coating film forming apparatus 300.
[0083] The wafer W having the coating film formed on its rear
surface is transferred by the wafer transfer body 101, for example,
to the post-exposure baking unit 84, where the wafer W is subjected
to predetermined processing. After completion of the thermal
processing in the post-exposure baking unit 84, the wafer W is
transferred by the second transfer arm 11 to the high-precision
temperature regulating unit 81, where the wafer W is
temperature-regulated, and then transferred to the developing
treatment unit 30, where developing treatment is performed on the
wafer W so that a pattern is formed in the resist film. The wafer W
is then transferred by the second transfer arm 11 to the
post-baking unit 75, where the wafer W is subjected to heating
processing, and subsequently transferred to the high-precision
temperature regulating unit 63, where the wafer W is
temperature-regulated. The wafer W is then transferred by the first
transfer arm 10 to the transition unit 61, and returned by the
wafer transfer body 7 to the cassette C, with which a series of
photolithography process ends.
[0084] After the photolithography processing is performed on the
wafer W in this manner (Steps S1 and S2 in FIG. 12), etching
treatment is performed to selectively etch the thin film on the
wafer W using the pattern formed in the resist film above the wafer
W as a mask (Step S3 in FIG. 12). Then, ashing processing of
stripping the resist film remaining above the wafer W, for example,
by generating plasma is performed (Step S4 in FIG. 12), and
cleaning treatment of removing contaminants such as metal and
organic substance adhering onto the wafer W is then performed (Step
S5 in FIG. 12).
[0085] Thereafter, the wafer W is transferred into the coating and
developing treatment system 1 so that the wafer W is subjected to
the photolithography processing for the second time. The wafer W
transferred in the interface section 4 after the wafer W is
subjected to above-described predetermined treatment and processing
such as the above-described formation of the resist film and so on
in the coating and developing treatment system 1 is transferred by
the wafer transfer body 101 to the coating film removing apparatus
200 in order to remove the coating film on the rear surface of the
wafer W before the wafer W is transferred to the exposure
processing apparatus 8 (Step S6 in FIG. 12).
[0086] The wafer W transferred by the wafer transfer body 101 into
the treatment container 250 is mounted on the wafer delivery table
240. The turning mechanism 263 then extends the transfer arm 260 to
a position of the wafer delivery table 240 so that the transfer arm
260 holds the wafer W.
[0087] The turning mechanism 263 then turns and inverts the wafer W
held by the transfer arm 260 to direct the rear surface of the
wafer W upward. In this state, the transfer mechanism 266 moves the
wafer W to above the spin chuck 220. The spin chuck 220 is then
raised to pass the wafer W from the transfer arm 260 to the spin
chuck 220. The transfer arm 260 is retracted from above the spin
chuck 260 and the inert gas is jetted from the gas supply port 224a
of the spin chuck 220, whereby the wafer W is horizontally held on
the spin chuck 220. The spin chuck 220 is then lowered to lower the
wafer W to a predetermined position.
[0088] Subsequently, the rotating mechanism 221 rotates the wafer
W, and the removing solution supply nozzle 230 is moved to above
the central portion of the wafer W. The removing solution is
discharged from the 10 removing solution supply nozzle 230 to the
central portion of the rear surface of the wafer W. The discharged
removing solution spreads over the rear surface of the wafer W by
the centrifugal force generated by rotation of the wafer W to
remove the coating film on the rear surface of the wafer W.
Thereafter, the removing solution supply nozzle 230 is moved from
above the central portion of the wafer W to the waiting region
237.
[0089] After removal of the coating film existing on the rear
surface of the wafer W, the rinse nozzle 270 is moved to above the
central portion of the wafer W so that the rinse solution is
discharged from the rinse nozzle 270 to the central portion of the
rear surface of the wafer W. The discharged rinse solution spreads
on the rear surface of the wafer W by the centrifugal force to
clean the rear surface of the wafer W.
[0090] After completion of the cleaning of the rear surface of the
wafer W, the wafer W on the spin chuck 220 is raised to a
predetermined position, and the transfer arm 260 is extended to
move to above the spin chuck 220. The wafer W is passed from the
spin chuck 220 to the transfer arm 260. The turning mechanism 263
then turns and inverts the wafer W to direct the front surface of
the wafer W upward, and the wafer W is passed from the transfer arm
260 to the wafer delivery table 240. The wafer W is then
transferred by the wafer transfer body 101 to the outside of the
coating film removing apparatus 200.
[0091] The wafer W having the coating film on its rear surface
removed is transferred by the wafer transfer body 101 to the
exposure processing apparatus 8, where the resist film above the
wafer W is exposed to light under a predetermined pattern (Step S7
in FIG. 12). The wafer W for which the exposure processing has been
finished is transferred by the wafer transfer body 101 to the
coating film forming apparatus 300, where the coating film is
formed on the rear surface of the wafer W (Step S8 in FIG. 12).
Thereafter, treatments such as the development of the resist film
and so on are performed, with which the photolithography processing
ends.
[0092] After performance of the photolithography processing for the
second time is performed on the wafer W, etching treatment for the
second time (Step S9 in FIG. 12), ashing processing for the second
time (Step S10 in FIG. 12), and cleaning treatment for the second
time (Step S11 in FIG. 12) are performed in sequence. The
photolithography processing, etching treatment, ashing processing,
and cleaning treatment (Steps S6 to S11 in FIG. 12) are performed
in this order a predetermined number of times, whereby multilayer
patterns are formed above the wafer W, with which a series of
treatment and processing of wafer W ends.
[0093] According to the above embodiment, the coating film is
formed on the rear surface of the wafer W in the coating film
forming apparatus 300 immediately after the exposure processing for
the wafer W is performed in the exposure processing apparatus 8, so
that even if the coating film on the rear surface of the wafer W
gets minute scratches during the etching treatment and the transfer
of the wafer W before reaching the exposure processing apparatus 8,
the rear surface of the wafer W itself is protected by the coating
film and thus never scratched. In the photolithography processing
subsequently performed, the coating film on the rear surface of the
wafer W is removed in the coating film removing apparatus 200
immediately before the exposure processing is performed in the
exposure processing apparatus 8, so that the rear surface of the
wafer W can be flat without projections and depressions for the
exposure processing. Therefore, the wafer W can be horizontally
held during the exposure processing to allow the exposure
processing to be appropriately performed.
[0094] Planarizing the rear surface of the wafer W before the
exposure of the pattern is particularly effective in the case of
performing double patterning processing that is used for forming a
fine pattern on the wafer W. In the double patterning processing,
the pattern to be formed in a fine layer on the wafer W is
subjected to exposure processing in twice in which the etching
treatment is performed after the exposure processing for the first
time and the exposure processing for the second time is performed
on the same layer. When the coating and developing treatment system
1 according to this embodiment is used for the double patterning
processing, the coating film is formed on the rear surface of the
wafer W immediately after the exposure processing for the first
time and the coating film is removed immediately before the
exposure processing for the second time, whereby the rear surface
of the wafer W can be protected by the coating film during the
etching treatment and the transfer of the wafer W, so that the rear
surface of the wafer W can be flat for the exposure processing.
Accordingly, the exposure processing in the double patterning
processing can be appropriately performed.
[0095] Since the coating film forming apparatus 300 and the coating
film removing apparatus 200 are provided in the coating and
developing treatment system 1, the formation of the coating film on
the rear surface of the wafer W and the removal of the coating film
can be performed in line, thus smoothly performing a series of
wafer treatment.
[0096] In the first treatment chamber 311 of the coating film
forming apparatus 300 of the above embodiment, a scribing brush 370
for cleaning the rear surface of the wafer W may further be
provided as shown in FIG. 13. The scribing brush 370 is located
above the spin chuck 320. A cleaning solution supply port (not
shown) is formed in the lower surface of the scribing brush 370,
and is connected to a cleaning solution supply source 372 via a
cleaning solution supply pipe 371. The cleaning solution supply
pipe 371 is also provided with a supply controller 373 including a
valve, a flow control unit, and so on.
[0097] The scribing brush 370 is connected to a moving mechanism
375 via an arm 374 as shown in FIG. 14. The moving mechanism 375 of
the scribing brush 370 and the moving mechanism 335 of the coating
nozzle 330 share the guide rail 336. The arm 374 of the scribing
brush 370 is configured such that it can be moved by the moving
mechanism 375 along the guide rail 336, from a waiting region 376
provided outside on the side of one end of the cup body 326 (the
left side in FIG. 14) toward the other end side and vertically
moved. The waiting region 376 is configured to be able to
accommodate the scribing brush 370 and includes a cleaning portion
376a which can clean the tip end portion of the scribing brush
370.
[0098] In this case, after the wafer W is passed from the transfer
arm 360 to the spin chuck 320, the wafer W is rotated by the
rotating mechanism 321 and the scribing brush 370 is brought into
contact with the rear surface of the wafer W. Thereafter, the rear
surface of the wafer W is cleaned while the cleaning solution is
being supplied from the cleaning solution supply port of the
scribing brush 370. After the contaminants adhering to the rear
surface of the wafer W are removed in the above manner, the
scribing brush 370 is moved from above the wafer W to the waiting
region 376. The coating nozzle 330 is moved to above the wafer W
and applies the coating solution to the rear surface of the wafer
W. The contaminants adhering to the rear surface of the wafer W are
removed by the scribing brush 370 immediately before the coating
solution is applied from the coating nozzle 330 to the rear surface
of the wafer W, thereby ensuring that a coating film to be formed
on the rear surface of the wafer W thereafter is planarized more
reliably.
[0099] In place of the removing solution supply nozzle 230 of the
coating film removing apparatus 200 used in the above embodiment, a
removing solution supply nozzle 280 may be used which has a
discharge port 280a in a slit form extending in the X-direction as
shown in FIG. 15. To the upper portion of the removing solution
supply nozzle 280, a removing solution supply pipe 281 is connected
which leads to a removing solution supply source 282. The removing
solution supply pipe 281 is also provided with a supply controller
283 including a valve, a flow control unit, and so on. As shown in
FIG. 16 and FIG. 17, the removing solution supply nozzle 280 is
formed, for example, longer than the width in the X-direction of
the wafer W, and is connected to a moving mechanism 285 via an arm
284. The arm 284 can be moved by the moving mechanism 285 along the
guide rail 236, from a waiting region 287 provided outside on the
side of one end of the cup body 226 (the right side in FIG. 17)
toward the other end side and vertically moved. The waiting region
287 can accommodate the removing solution supply nozzle 280.
[0100] In the case where the removing solution supply nozzle 280 is
used as described above, movement of the moving mechanism 285
allows the removing solution to be discharged from the removing
solution supply nozzle 280 to the rear surface of the wafer W.
Accordingly, in place of the rotating mechanism 221 which rotates
and raises and lowers the spin chuck 220, a raising and lowering
mechanism 229 may be used which can only raise and lower the spin
chuck 220 as shown in FIG. 16.
[0101] For the coating nozzle 330 of the coating film forming
apparatus 300 used in the above embodiment, a coating nozzle may be
used which has the above-described discharge port in a slit
form.
[0102] In place of the spin chuck 220 of the coating film removing
apparatus 200 used in the above embodiment, a spin chuck 400 may be
used which has a removing solution supply nozzle 410 and a rinse
nozzle 420 therein as shown in FIG. 18 and FIG. 19. The removing
solution supply nozzle 410 and the rinse nozzle 420 provided inside
the spin chuck 400 are installed at a slant each inclining from the
vertical direction toward the center. The removing solution supply
nozzle 410 and the rinse nozzle 420 can discharge the removing
solution and the rinse solution from the upper surface of the spin
chuck 400 toward the lower surface of the wafer W,
respectively.
[0103] The removing solution supply nozzle 410 is connected to a
removing solution supply source 412 via a removing solution supply
pipe 411 passing through the spin chuck 400. The rinse nozzle 420
is similarly connected to a rinse solution supply source 422 via a
rinse solution supply pipe 421 passing through the spin chuck 400.
At the central portion of the upper surface of the spin chuck 400,
a recessed portion 402 is formed downward, so that a space 401 is
formed between the recessed portion 402 and the wafer W. At the
central portion of the upper surface of the spin chuck 400, a gas
supply port 402a is formed which jets an inert gas, for example,
nitrogen gas toward the space 401, and a gas supply pipe 403
penetrating through the spin chuck 400 is connected to the gas
supply port 402a. On the upper surface of the spin chuck 400, for
example, eight holding pins 404 for holding the peripheral portion
of the wafer W are provided along the peripheral portion of the
wafer W. The holding pin 404 has the same shape as that of the
holding pin 222.
[0104] In this case, the wafer W transferred by the transfer body
101 to the coating film removing apparatus 200 is passed from the
wafer transfer body 101 to the spin chuck 400 by raising the spin
chuck 400. The inert gas is then jetted from the gas supply port
402a toward the space 401 to fix the wafer W to the spin chuck 400,
and then the wafer W is lowered to a predetermined position. The
rotating mechanism 221 rotates the wafer W, and the removing
solution is discharged from the removing solution supply nozzle 400
to the rear surface of the wafer W to remove the coating film on
the rear surface of the wafer W. Thereafter, the rinse solution is
discharged from the rinse nozzle 410 to the rear surface of the
wafer W to clean the rear surface of the wafer W. Using the coating
film removing apparatus 200 as described above allows the coating
film on the rear surface of the wafer W to be removed with the rear
surface of the wafer W directed downward.
[0105] Note that in the case where such a spin chuck 400 is used,
the removing solution can be discharged to the rear surface of the
wafer W with the front surface of the wafer W directed upward, so
that the wafer delivery table 140 and the transfer arm 260 which
are provided for inverting the wafer W and members and mechanisms
associated with them become unnecessary and thus may be omitted
from the coating film removing apparatus 200.
[0106] In place of the spin chuck 220 of the coating film removing
apparatus 200 used in the above embodiment, three spin chucks 430,
431, and 431 may be used which vacuum-sucks the rear surface of the
wafer W as shown in FIG. 20. The first spin chuck 430 is located to
suction-hold the central portion of the wafer W. The second spin
chucks 431 and 431 are located to suck the position other than the
portion which is sucked by the first spin chuck 430 so that the two
spin chucks 431 and 431 hold the wafer W. Below the spin chucks
430, 431 and 431, a rotating mechanism 440 is provided which can
rotate and raise and lower the first spin chuck 430 and the second
spin chucks 431 and 431 independently. Obliquely below the wafer W
held by the spin chucks 430, 431 and 431, a removing solution
supply nozzle 450 and a rinse nozzle 460 are separately provided in
the cup body 226. The removing solution supply nozzle 450 is
connected to a removing solution supply source 452 via a removing
solution supply pipe 451. The rinse nozzle 460 is connected to a
rinse solution supply nozzle 462 via a rinse solution supply pipe
461.
[0107] In this case, the wafer W transferred by the wafer transfer
body 101 to the coating film removing apparatus 200 is passed from
the wafer transfer body 101 to the first spin chuck 430 by raising
the first spin chuck 430. The wafer W suction-held by the first
spin chuck 430 is then lowered to a predetermined position. The
wafer W is then rotated by the rotating mechanism 440, and the
removing solution is discharged from the removing solution supply
nozzle 450 to the rear surface of the wafer W to remove the coating
film on the rear surface at a portion other than the portion which
is sucked by the first spin chuck 430.
[0108] Subsequently, the rotation of the wafer W is stopped, the
second spin chucks 431 and 431 are raised to suction-hold the rear
surface of the wafer W, and the first spin chuck 430 is lowered.
The wafer W is then rotated again, and the removing solution is
discharged from the removing solution supply nozzle 450 to the rear
surface of the wafer W to remove the coating film at the central
portion which has been sucked by the first spin chuck 430. As a
result, the coating solution on the entire rear surface of the
wafer W can be removed.
[0109] Thereafter, the rinse solution is discharged from the rinse
nozzle 460 to the rear surface of the wafer W to clean the rear
surface of the wafer W. For this cleaning, the rear surface of the
wafer W is cleaned in twice in which cleaning is performed with the
wafer W being sucked by the first spin chuck 430 and cleaning is
performed with the wafer W being sucked by the second spin chucks
431 and 431 whereby the entire rear surface of the wafer W can be
cleaned. Using the coating film removing apparatus 200 as described
above allows the coating film on the rear surface of the wafer W to
be removed with the rear surface of the wafer W directed
downward.
[0110] In the case where such spin chucks 430 and 431 are used, the
removing solution can be discharged to the rear surface of the
wafer W with the front surface of the wafer W directed upward, so
that the wafer delivery table 140 and the transfer arm 260 which
are provided for inverting the wafer W and members and mechanisms
associated with them become unnecessary and thus may be omitted
from the coating film removing apparatus 200.
[0111] In place of the lamp heating unit 341 in the coating film
forming apparatus 300 in the above embodiment, any conventional
ultraviolet irradiation unit (not shown) for applying ultraviolet
rays and a conventional electron beam irradiation unit (not shown)
for applying electron beams to the coating solution applied on the
wafer W may be provided. This allows selective use of the lamp
heating unit 341, the ultraviolet irradiation unit, or the electron
beam irradiation unit depending on the kind of the coating solution
in use.
[0112] Although the coating film removing apparatus 200 is provided
in the coating and developing treatment system 1 in the above
embodiment, the coating film removing apparatus 200 may be provided
outside the coating and developing treatment system 1. As such an
example, a coating film removing system 500 has, as shown in FIG.
21 and FIG. 22, a configuration in which, for example, a cassette
station 501 for transferring 25 wafers W per cassette as a unit
from/to the outside into/from the coating film removing system 500
and transferring the wafers W into/out of a cassette C; and a
treatment station 502 for performing treatment of removing the
coating film on the rear surface of the wafer W, are integrally
connected.
[0113] In the cassette station 501, a cassette mounting table 503
is provided and configured such that a plurality of cassettes C can
be mounted thereon in a line in an X-direction (a top-to-bottom
direction in FIG. 21). In the cassette station 501, a wafer
transfer body 505 is provided which is movable in the X-direction
on a transfer path 504. The wafer transfer body 505 is also movable
in a wafer-arrangement direction of the wafers W housed in the
cassette C (a Z-direction; the vertical direction), and thus can
selectively access the wafer W in each of the cassettes C arranged
in the X-direction. The wafer transfer body 505 is rotatable in a
.theta.-direction around a Z-axis, and can access a later-described
coating film removing apparatus 200 on the treatment station 502
side.
[0114] On the side of the positive direction in the X-direction
(the upward direction in FIG. 21) in the treatment station 502,
treatment unit groups G10 and G20 are placed in order from the
cassette station 501 side, and on the side of the negative
direction in the X-direction (the downward direction in FIG. 21),
treatment unit groups G30 and G40 are placed in order from the
cassette station 501 side. Between the treatment unit groups G10
and G20, and the treatment unit groups G30 and G40, a wafer
transfer body 507 which is movable in the Y-direction on a transfer
path 506 is provided. The wafer transfer body 507 is also movable
in the X-direction and the vertical direction (the Z-direction) and
rotatable in the .theta.-direction around the Z-axis to selectively
access the treatment units in the treatment unit groups G10, G20,
G30, and G40 and transfer the wafer W to them.
[0115] In each of the treatment unit groups G30 and G40, as shown
in FIG. 22, the coating film removing apparatuses 200 are
four-tiered. Also in each of the treatment unit groups G10 and G20,
the coating film removing apparatuses 200 are four-tiered. More
specifically, a total of 16 coating film removing apparatuses 200
are provided in the treatment station 502. Since the plurality of
coating film removing apparatuses 200 are provided in the coating
film removing system 500, the coating films on the rear surfaces of
a plurality of wafers W can be removed at the same time.
[0116] The removal of the coating film on the rear surface of the
wafer W by the coating film removing system 500 is performed, for
example, after the etching treatment of the wafer W and before the
ashing processing (an arrow a in FIG. 23). Thereby, even if the
coating film on the rear surface of the wafer W gets minute
scratches during performance of the etching treatment, the rear
surface of the wafer W itself is protected by the coating film and
thus never scratched, so that the rear surface of the wafer W can
be flat for the exposure processing to be performed subsequent
thereto. Note that the removal of the coating film by the coating
film removing system 500 may be performed after the ashing
processing and before the cleaning treatment (an arrow b in FIG.
23), or after the cleaning treatment and before the
photolithography processing (an arrow c in FIG. 23).
[0117] Although the coating film forming apparatus 300 is provided
in the coating and developing treatment system 1 in the above
embodiment, the coating film forming apparatus 300 may be provided
outside the coating and developing treatment system 1. As such an
example, a coating film forming system 600 has a configuration in
which treatment unit groups G50 to G80 as shown in FIG. 24, in
place of the treatment unit groups G10 to G40 of the coating film
removing system 500. In each of the treatment unit groups G50 to
G80, the coating film forming apparatuses 300 are four-tiered.
[0118] The formation of the coating film on the rear surface of the
wafer W by the coating film forming system 600 is performed, for
example, after the photolithography processing for the wafer W and
before the etching treatment (an arrow d in FIG. 23). Thereby, even
if the coating film on the rear surface of the wafer W gets minute
scratches during the etching treatment, the rear surface of the
wafer W itself is protected by the coating film and thus never
scratched, so that the rear surface of the wafer W can be flat for
the exposure processing subsequent thereto. Note that the formation
of the coating film on the rear surface of the wafer W by the
coating film forming system 600 may be performed before the
photolithography processing performed for the first time (an arrow
e in FIG. 23).
[0119] Although the inside of the coating film forming apparatus
300 is divided into the first treatment chamber 311 and the second
treatment chamber 312 in the above embodiment, the first treatment
chamber 311 and the second treatment chamber 312 may be divided
into separate units. More specifically, the coating film forming
apparatus 300 may be divided into a unit for applying the coating
solution from the coating nozzle 330 to the rear surface of the
wafer W and a unit for heating the wafer W using the lamp heating
unit 341 to cure the coating solution on the rear surface of the
wafer W.
[0120] Although the coating film is formed on the rear surface of
the wafer W by applying the coating solution in the above
embodiment, a thin film may be formed on the rear surface of the
wafer W, for example, by the CVD (Chemical Vapor Deposition)
method. In other words, a material gas may be supplied to the rear
surface of the wafer W to deposit into a thin film on the rear
surface of the wafer W by chemical catalytic reaction so as to
protect the rear surface of the wafer W.
[0121] Preferred embodiments of the present invention have been
described above with reference to the accompanying drawings, but
the present invention is not limited to the embodiments. It should
be understood that various changes and modifications within the
scope of the spirit as set forth in claims are readily apparent to
those skilled in the art, and those should also be covered by the
technical scope of the present invention. The present invention is
also applicable, for example, to the case where the substrate is a
substrate other than the wafer, such as an FPD (Flat Panel
Display), a mask reticle for a photomask, or the like.
[0122] The present invention is useful to a method of treating a
substrate, for example, a semiconductor wafer or the like, a
coating film removing apparatus, and a substrate treatment
system.
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