U.S. patent application number 10/824422 was filed with the patent office on 2004-09-30 for processing apparatus for processing sample in predetermined atmosphere.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Hara, Shinichi, Tanaka, Yutaka, Terashima, Shigeru.
Application Number | 20040187786 10/824422 |
Document ID | / |
Family ID | 18701744 |
Filed Date | 2004-09-30 |
United States Patent
Application |
20040187786 |
Kind Code |
A1 |
Tanaka, Yutaka ; et
al. |
September 30, 2004 |
Processing apparatus for processing sample in predetermined
atmosphere
Abstract
A load-lock chamber has a substrate transfer path between a
first gas atmosphere and a second gas atmosphere. The load-lock
chamber includes a first gate valve through which a substrate is
transferred between the first gas atmosphere and the load-lock
chamber, a second gate valve through which a substrate is
transferred between the second gas atmosphere and the load-lock
chamber and a gas supply mechanism which supplies the first gas and
the second gas to the load-lock chamber. The gas supply mechanism
is arranged to supply the second gas to the load-lock chamber when
the first gate valve is closed and the second gate valve is opened
during the substrate being transferred between the second
atmosphere and the load-lock chamber.
Inventors: |
Tanaka, Yutaka; (Tochigi,
JP) ; Terashima, Shigeru; (Tochigi, JP) ;
Hara, Shinichi; (Saitama, JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
18701744 |
Appl. No.: |
10/824422 |
Filed: |
April 15, 2004 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
10824422 |
Apr 15, 2004 |
|
|
|
09897930 |
Jul 5, 2001 |
|
|
|
6750946 |
|
|
|
|
Current U.S.
Class: |
118/719 |
Current CPC
Class: |
H01L 21/67017 20130101;
G03F 7/7075 20130101; G03F 7/70808 20130101; G03F 7/70866 20130101;
H01L 21/67201 20130101; G03F 7/70841 20130101; H01L 21/67196
20130101 |
Class at
Publication: |
118/719 |
International
Class: |
C23C 016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 6, 2000 |
JP |
204491/2000 (PAT. |
Claims
1-13. Cancel.
14. A load-lock chamber having a substrate transfer path between a
first gas atmosphere and a second gas atmosphere, the load-lock
chamber comprising: a first gate valve through which a substrate is
transferred between the first gas atmosphere and the load-lock
chamber; a second gate valve through which a substrate is
transferred between the second gas atmosphere and the load-lock
chamber; and a gas supply mechanism which supplies the first gas
and the second gas to the load-lock chamber, wherein the gas supply
mechanism is arranged to supply the second gas to the load-lock
chamber when the first gate valve is closed and the second gate
valve is opened during the substrate being transferred between the
second atmosphere and the load-lock chamber.
15. A load-lock chamber having a substrate transfer path between a
first gas atmosphere and a second gas atmosphere, the load-lock
chamber comprising: a gas supply pipe which supplies the first gas
and the second gas to the load-lock chamber; and a straightening
plate provided at an entire upper portion of an interior space
within the load-lock chamber to cause the flow of the first gas and
the second gas supplied through the gas supply pipe to be
uniform.
16. The load-lock chamber according to claim 15, wherein the
straightening plate comprises a metal plate with a plurality of
perforations formed therein.
17. A substrate processing system, comprising: a load-lock chamber
having a substrate transfer path between a first gas atmosphere and
a second gas atmosphere, the load-lock chamber including a first
gate valve through which a substrate is transferred between the
first gas atmosphere and the load-lock chamber, a second gate valve
through which a substrate is transferred between the second gas
atmosphere and the load-lock chamber, and a gas supply mechanism
which supplies the first gas and the second gas to the load-lock
chamber, the gas supply mechanism being arranged to supply the
second gas to the load-lock chamber when the first gate valve is
closed, and the second gate valve is opened during the substrate
being transferred between the second atmosphere and the load-lock
chamber; and a processing device adapted to process the substrate
in the first gas atmosphere.
18. An exposure processing system comprising: a load-lock chamber
having a substrate transfer path between a first gas atmosphere and
a second gas atmosphere, the load-lock chamber including a first
gate valve through which a substrate is transferred between the
first gas atmosphere and the load-lock chamber, a second gate valve
through which a substrate is transferred between the second gas
atmosphere and the load-lock chamber, and a gas supply mechanism
which supplies the first gas and the second gas to the load-lock
chamber, the gas supply mechanism being arranged to supply the
second gas to the load-lock chamber when the first gate valve is
closed and the second gate valve is opened during the substrate
being transferred between the second atmosphere and the load-lock
chamber; and an exposure device adapted to expose the substrate in
the first gas atmosphere.
19. A device manufacturing method, comprising: exposing a substrate
using an exposure processing system defined in claim 18; and
developing the exposed substrate using a developer.
20. A substrate processing system comprising: a load-lock chamber
having a substrate transfer path between a first gas atmosphere and
a second gas atmosphere, the load-lock chamber including a gas
supply pipe which supplies the first gas and the second gas to the
load-lock chamber, and a straightening plate provided at an entire
upper portion of an interior space within the load-lock chamber to
cause the flow of the first gas and the second gas supplied through
the gas supply pipe to be uniform; and a processing device adapted
to process the substrate in the first gas atmosphere.
21. An exposure processing system comprising: a load-lock chamber
having a substrate transfer path between a first gas atmosphere and
a second gas atmosphere, the load-lock chamber including a gas
supply pipe which supplies the first gas and the second gas to the
load-lock chamber, and a straightening plate provided at an entire
upper portion of an interior space within the load-lock chamber to
cause the flow of the first gas and the second gas supplied through
the gas supply pipe to be uniform; and an exposure device adapted
to expose the substrate in the first gas atmosphere.
22. A device manufacturing method comprising: exposing a substrate
using an exposure processing system defined in claim 21; and
developing the exposed substrate using a developer.
Description
FIELD OF THE INVENTION
[0001] The present invention relates to a sample processing
apparatus and method and device manufacturing method and, more
particularly, to a sample processing apparatus and method and
device manufacturing method, which process a sample such as a wafer
in a predetermined atmosphere such as a reduced-pressure atmosphere
of a specific gas and are suitable for an X-ray exposure apparatus,
F2 exposure apparatus, CVD apparatus, and the like.
BACKGROUND OF THE INVENTION
[0002] As an example of a processing apparatus for processing a
substrate in a predetermined atmosphere such as a reduced-pressure
atmosphere, an X-ray exposure apparatus for transferring a pattern
formed on a mask onto a wafer in reduced-pressure helium atmosphere
is known (Japanese Patent-Laid Open No. 2-100311).
[0003] FIG. 7 is a view showing a conventional semiconductor
manufacturing apparatus. This apparatus uses, as exposure light, SR
light, i.e., synchrotron radiation (synchrotron radiation) as soft
X-rays and comprises an SR light source 101 for generating the SR
light, a beam line 102, and a hermetic process chamber 103. The
beam line 102 having an ultra-high vacuum atmosphere is connected
to the SR light source 101 through a gate valve 102a to guide SR
light to the process chamber 103.
[0004] A mask M.sub.0 with a transfer pattern formed on a thin
membrane and a wafer W.sub.0 are placed in the process chamber 103.
The mask M.sub.0 and wafer W.sub.0 are placed on alignment stages
(not shown), respectively. At the time of exposure in which the
pattern formed on the mask M.sub.0 is transferred onto the wafer
W.sub.0, a helium atmosphere at a reduced pressure of, e.g., 150
Torr is set in the process chamber 103 to suppress any attenuation
of the SR light as exposure light.
[0005] The process chamber 103 has an X-ray window 104 which is
normally made of beryllium. The X-ray window 104 serves as a
partition for separating the helium atmosphere in the process
chamber 103 from the ultra-high vacuum atmosphere in the beam line
102.
[0006] In such a processing apparatus, if the entire process
chamber 103 is opened to outer air every time the mask M.sub.0 or
wafer W.sub.0 is loaded to or unloaded from the process chamber
103, a considerably long time is required to open the process
chamber to outer air and set the predetermined atmosphere. This
reduces the throughput. To avoid this problem, a small load-lock
chamber 105 is arranged next to the process chamber 103 such that
the mask M.sub.0 or wafer W.sub.0 is loaded/unloaded to/from the
process chamber 103 through the load-lock chamber 105. The
load-lock chamber 105 has a gate valve 106 on the process chamber
side and a gate valve 107 on the outer air side.
[0007] The apparatus also has a coater/developer 108 for applying a
resist onto the wafer and developing the wafer after exposure, and
a transfer mechanism 109 inserted between the load-lock chamber 105
and the coater/developer 108 to transfer the wafer.
[0008] The procedure of loading the wafer W.sub.0 to the process
chamber 103 will be described below.
[0009] (STEP 1) The gate valve 107 on the outer air side is opened,
and the wafer is fed to the load-lock chamber 105 by the transfer
mechanism 109. At this time, the gate valve 106 on the process
chamber 103 side is kept closed.
[0010] (STEP 2) The gate valve 107 on the outer air side is closed,
and a reduced-pressure helium atmosphere is set in the load-lock
chamber 105.
[0011] (STEP 3) The gate valve 106 on the process chamber 103 side
is opened, and the wafer W.sub.0 is transferred into the process
chamber 103 by a transfer mechanism (not shown) in the process
chamber 103.
[0012] For unloading, the procedures are reversed.
[0013] In the conventional semiconductor manufacturing process, the
whole manufacturing apparatus is installed in a clean room of a
factory, thereby taking a measure against contamination by dust or
the like. However, for micropatterning of 0.2- to 0.1-.mu.m level
coping with recent semiconductor integration, the required
cleanliness becomes strict from class 10 to class 1. To achieve
this cleanliness in the entire clean room, the clean room
building/maintenance cost becomes incredibly high. In addition,
maintenance of one apparatus decreases the cleanliness in the
entire clean room, resulting in adverse effect on other
apparatuses.
[0014] As described above, the processing apparatus requires a
load-lock chamber to improve the throughput. Since the load-lock
chamber atmosphere changes from outer air to the same atmosphere as
in the process chamber 103 and vice versa, the cleanliness must be
managed depending on the atmosphere.
SUMMARY OF THE INVENTION
[0015] The present invention has been made in consideration of the
above conventional problems, which are kept unsolved, and has as
its object to provide a processing apparatus and method and a
device manufacturing method which can inexpensively manage the
cleanliness throughout the transfer path for a sample such as a
substrate and effectively avoid contamination of the sample.
[0016] It is the second object of the present invention to manage
the cleanliness throughout the sample transfer path and efficiently
manage the cleanliness in the load-lock chamber at the time of
loading/unloading a sample.
[0017] It is the third object of the present invention to manage
the cleanliness throughout the sample transfer path and easily
manage the cleanliness in the load-lock chamber depending on the
atmosphere.
[0018] It is the fourth object of the present invention to manage
the cleanliness throughout the sample transfer path and manage the
cleanliness in the load-lock chamber depending on the atmosphere
while suppressing moisture mixing.
[0019] The first aspect of the present invention is related to a
processing apparatus for processing a sample. The processing
apparatus comprises a process chamber for processing the sample in
a predetermined atmosphere, a load-lock chamber connected to the
process chamber, a transfer mechanism for transferring the sample
between the load-lock chamber and another unit or container, a
clean booth which covers a transfer path of the transfer mechanism,
and a transfer atmosphere forming mechanism for flowing a clean gas
in the clean booth.
[0020] According to a preferred embodiment of the present
invention, the transfer atmosphere forming mechanism preferably
comprises, e.g., a supply source of the gas, and a filter inserted
between the supply source of the gas and the transfer path, and
more preferably, further comprises a straightening plate for
passing the gas from the filter, which has passed through the
transfer path.
[0021] According to a preferred embodiment of the present
invention, the processing apparatus preferably further comprises,
in the load-lock chamber, a gas control mechanism for supplying a
clean gas which is the same as in the process chamber or as in the
clean booth into the load-lock chamber or exhausting the gas from
the load-lock chamber. To supply the gas which is the same as in
the process chamber to the load-lock chamber, the gas control
mechanism supplies, e.g., the clean gas in the process chamber to
the load-lock chamber, and to supply the gas which is the same as
in the clean booth to the load-lock chamber, the gas control
mechanism supplies, e.g., the clean gas in the clean booth to the
load-lock chamber. More preferably, gates are arranged between the
load-lock chamber and the process chamber and between the load-lock
chamber and the clean booth, in transferring the sample from the
load-lock chamber to the process chamber, the gas control mechanism
supplies the same clean gas as in the process chamber to the
load-lock chamber before the gate between the load-lock chamber and
the process chamber is opened, and in transferring the sample from
the load-lock chamber to the clean booth, the gas control mechanism
supplies the same clean gas as in the clean booth to the load-lock
chamber before the gate between the load-lock chamber and the clean
booth is opened.
[0022] According to a preferred embodiment of the present
invention, the processing apparatus preferably further comprises,
in the load-lock chamber, a gas control mechanism for supplying a
clean gas which is the same as in the process chamber or a clean
dry gas into the load-lock chamber or exhausting the gas from the
load-lock chamber. More preferably, gates are arranged between the
load-lock chamber and the process chamber and between the load-lock
chamber and the clean booth, in transferring the sample from the
load-lock chamber to the process chamber, the gas control mechanism
supplies the same clean gas as in the process chamber to the
load-lock chamber before the gate between the load-lock chamber and
the process chamber is opened, and in transferring the sample from
the load-lock chamber to the clean booth, the gas control mechanism
supplies the clean dry gas to the load-lock chamber before the gate
between the load-lock chamber and the clean booth is opened.
[0023] According to a preferred embodiment of the present
invention, the transfer atmosphere forming mechanism forms a
laminar flow of the clean gas in the clean booth.
[0024] According to a preferred embodiment of the present
invention, preferably, the processing apparatus further comprises
an exposure apparatus in the process chamber, and another unit
comprises a coater/developer.
[0025] Another aspect of the present invention is related to a
method of processing a sample, comprising the steps of transferring
the sample to a load-lock chamber by a transfer mechanism installed
in a clean booth in which a clean gas flows, adjusting a pressure
in the load-lock chamber and transferring the sample from the
load-lock chamber into a process chamber, processing the sample in
the process chamber, transferring the sample from the process
chamber to the load-lock chamber, and adjusting the pressure in the
load-lock chamber, extracting the sample from the load-lock
chamber, and transferring the sample by the transfer mechanism
installed in the clean booth in which the clean gas flows.
[0026] According to still another aspect of the present invention
is related to a method of manufacturing a device, comprising the
steps of transferring a substrate coated with a photosensitive
agent to a load-lock chamber by a transfer mechanism installed in a
clean booth in which a clean gas flows, adjusting a pressure in the
load-lock chamber and transferring the substrate from the load-lock
chamber into a process chamber, transferring a pattern onto the
substrate by an exposure apparatus installed in the process
chamber, transferring the substrate from the process chamber to the
load-lock chamber, and adjusting the pressure in the load-lock
chamber, extracting the substrate from the load-lock chamber, and
transferring the substrate by the transfer mechanism installed in
the clean booth in which the clean gas flows.
[0027] The preferred embodiment of the present invention solves a
problem that if the transfer mechanism for transferring the
substrate to be processed from the coater/developer for executing
preprocess and post-process of the substrate to be processed to the
load-lock chamber is exposed to air in the clean room, the
cleanliness in the entire clean room must be increased to maintain
the cleanliness of the atmosphere in the process chamber and
load-lock chamber, resulting in an increase in cost. According to
the preferred embodiment of the present invention, the entire
transfer path by the transfer mechanism is arranged in the clean
booth, and a laminar flow of a clean gas is formed in the clean
booth, thereby preventing dust from sticking to the substrate to be
processed.
[0028] According to a preferred embodiment of the present
invention, the substrate such as a wafer to be processed can be
kept in the clean state during transfer only by managing the
compact clean booth without increasing the cleanliness in the
entire clean room. For this reason, as compared to the case wherein
the entire clean room is strictly managed, the cost can be reduced,
and the maintenance does not adversely affect other
apparatuses.
[0029] Providing a load-lock chamber gas fluidizing mechanism (gas
control mechanism) for generating a laminar flow of a clean gas in
the load-lock chamber in accordance with the preferred embodiment
of the present invention is very effective in keeping the substrate
to be processed in the load-lock chamber clean.
[0030] When the gas control mechanism for selectively supplying the
ambient gas in the process chamber or air in the clean booth to the
load-lock chamber is arranged in accordance with the preferred
embodiment of the present invention so as to circulate the gas, the
cost can be further reduced.
[0031] When the gas control mechanism for selectively supplying the
ambient gas in the process chamber or dry gas to the load-lock
chamber is arranged in accordance with the preferred embodiment of
the present invention, moisture can be prevented from entering the
load-lock chamber to prevent contamination of the substrate to be
processed, or the vacuum suction time can be shortened.
[0032] Other features and advantages of the present invention will
be apparent from the following description taken in conjunction
with the accompanying drawings, in which like reference characters
designate the same or similar parts throughout the figures
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0033] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention and, together with the description, serve to explain
the principles of the invention.
[0034] FIG. 1 is a schematic view showing the first embodiment;
[0035] FIGS. 2A and 2B are views for explaining pipe switching in
the apparatus shown in FIG. 1;
[0036] FIG. 3 is a schematic view showing a modification to the
first embodiment;
[0037] FIG. 4 is a schematic view showing the second
embodiment;
[0038] FIG. 5 is a flow chart showing a semiconductor manufacturing
process;
[0039] FIG. 6 is a flow chart showing a wafer process; and
[0040] FIG. 7 is a schematic view showing a prior art.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0041] The embodiments of the present invention will be described
with reference to the accompanying drawings.
[0042] FIG. 1 is a view showing a processing apparatus according to
the first embodiment of the present invention. This processing
apparatus is a semiconductor manufacturing apparatus including an
X-ray exposure apparatus of a so-called inline system, which has an
exposure system using SR light, i.e., soft X-rays as exposure light
and continuously processes wafers as substrates to be processed.
The apparatus has an SR light source 1 for generating SR light, a
beam line 2, and a hermetic process chamber 3.
[0043] The beam line 2 has an ultra-high vacuum atmosphere and is
connected to the SR light source 1 through a gate valve 2a. The SR
light from the SR light source 1 is guided to the process chamber 3
through the beam line 2. A mask M with a transfer pattern formed on
a thin membrane and a wafer W are placed in the process chamber 3.
The mask M and wafer W are placed on alignment stages (not shown),
respectively. At the time of exposure in which the pattern formed
on the mask M is transferred onto the wafer W, a reduced-pressure
helium atmosphere at a reduced pressure of, e.g., 150 Torr is set
in the process chamber 3 to suppress any attenuation of the SR
light as exposure light. The process chamber 3 has an X-ray window
4 which is generally made of beryllium. The X-ray window 4 serves
as a partition for separating the helium atmosphere in the process
chamber 3 from the ultra-high vacuum atmosphere in the beam line
2.
[0044] In such a processing apparatus for processing a wafer in a
predetermined atmosphere, if the entire process chamber 3 is opened
to outer air or clean room atmosphere every time the mask M or
wafer W is loaded to or unloaded from the process chamber 3, a
considerably long time is required to open the process chamber to
outer air and set the above-described reduced-pressure atmosphere
as the predetermined atmosphere. This reduces the throughput. To
avoid this problem, a small load-lock chamber 5 is arranged next to
the process chamber 3 such that the mask M or wafer W is
loaded/unloaded to/from the process chamber 3 through the load-lock
chamber 5. The load-lock chamber 5 has a gate valve 6 on the
process chamber side and a gate valve 7 on the outer air side (on
the clean booth (to be described later) side).
[0045] The apparatus also has a coater/developer 8 for applying a
resist onto the wafer before exposure and developing the wafer
after exposure, and a transfer mechanism 9 inserted between the
load-lock chamber 5 and the coater/developer 8 to transfer the
wafer.
[0046] A filter 10 for removing particles and chemical components
is provided on the upper side of the process chamber 3. A
straightening plate 11 is arranged on the entire lower surface.
Helium as the ambient gas in the process chamber 3 is exhausted by
a helium circulation unit 12 and returned to the upper side of the
filter 10 in the process chamber 3 through a helium circulation
duct 13. With this arrangement, a laminar flow of clean helium is
formed in the process chamber 3.
[0047] On the outer air side of the load-lock chamber 5, a clean
booth 14 is provided, which has one surface connected to the gate
valve 7 and the other surface connected to the coater/developer 8
and covers the whole wafer transfer path by the transfer mechanism
9. The clean booth 14 has a clean booth gas fluidizing mechanism or
transfer atmosphere forming mechanism which comprises a filter 15
arranged above the full range of the transfer path by the transfer
mechanism 9, an air circulation unit 16, an air circulation duct
17, and a straightening plate 16a arranged below the full range of
the transfer path by the transfer mechanism 9. The air in the clean
booth 14 is exhausted by the air circulation unit 16 and returned
above the filter 15 in the clean booth 14 through the air
circulation duct 17. With this arrangement, a laminar flow of clean
air with high cleanliness is formed in the full range of the wafer
transfer path.
[0048] A straightening plate 18 is arranged under the entire upper
surface of the load-lock chamber 5. A supply pipe 19 that opens to
the upper side of the straightening plate 18 has one end connected
to the load-lock chamber 5 and the other side connected to the
process chamber 3 and clean booth 14 through a supply switching
valve 20 serving as a selection mechanism or gas control mechanism,
thereby constructing a load-lock chamber gas fluidizing mechanism.
By the supply switching valve 20, one of three states can be
selected: 1) a state wherein no gas is supplied into the load-lock
chamber 5, 2) a state wherein helium is supplied into the load-lock
chamber 5 through the supply pipe 19 (state wherein the valve is
opened to the "process chamber 3 side"), or 3) a state wherein air
is supplied into the load-lock chamber 5 through the supply pipe 19
(state wherein the valve is opened to the "clean booth 14
side").
[0049] One end of an exhaust pipe 21 is connected to the load-lock
chamber 5, and the other end is connected to an exhaust unit 23,
helium circulation unit 12, and air circulation unit 16 through an
exhaust switching valve 22. By the exhaust switching valve 22, one
of three states can be selected: 1) a state wherein the gas is
exhausted from the load-lock chamber 5 through the exhaust pipe 21
by the exhaust mechanism 23 ("exhaust"), 2) air is circulated
through the load-lock chamber 5 ("air circulation"), or 3) a state
wherein helium is circulated through the load-lock chamber 5
("helium circulation"). The straightening plate 18 is formed from,
e.g., a punching metal with a number of perforations formed in a
metal plate so as to form, in the load-lock chamber 5, a uniform
flow (laminar flow) of a gas supplied through the supply pipe
19.
[0050] The procedure of loading the wafer W to the process chamber
3 will be described below.
[0051] (STEP 0) First, the process chamber 3 is exhausted to a
vacuum (e.g., 0.1 Torr) by an exhaust mechanism (not shown), and
helium is supplied to, e.g., 150 Torr by a helium supply mechanism
(not shown). After that, the helium circulation unit 12 is driven
to form a laminar flow of helium in the process chamber 3. At this
time, the gate valve 6 on the process chamber 3 is kept closed, and
the gate valve 7 on the outer air side (clean booth 14 side) is
kept open. The supply switching valve 20 is switched to the clean
booth 14 side, and the exhaust switching valve 22 is switched to
air circulation, thereby forming a laminar flow of clean air in the
load-lock chamber 5 (FIG. 2B).
[0052] (STEP 1) A wafer coated with a resist by the
coater/developer 8 is fed into the load-lock chamber 5 by the
transfer mechanism 9 in the clean booth 14. Since the laminar flow
of clean air is formed in the clean booth 14 and load-lock chamber
5, i.e., throughout the transfer path, the wafer can be transferred
while keeping a very high cleanliness.
[0053] (STEP 2) The gate valve 7 and supply switching valve 20 are
closed, the exhaust switching valve 22 is switched to exhaust by
the exhaust mechanism 23, and the load-lock chamber 5 is exhausted
to 0.1 Torr. After that, the exhaust switching valve 22 is switched
to helium circulation.
[0054] (STEP 3) The supply switching valve 20 is switched to the
process chamber 3 side. At this time, a decrease in pressure in the
process chamber 3 can be compensated with helium by the helium
supply mechanism (not shown), as needed. In this state, a laminar
flow of helium is formed in the load-lock chamber 5, as in the
process chamber 3 (FIG. 2A).
[0055] (STEP 4) When the pressure in the load-lock chamber 5 equals
that in the process chamber 3, the gate valve 6 on the process
chamber 3 side is opened, and the wafer is transferred into the
process chamber 3 by the transfer mechanism (not shown) in the
process chamber 3.
[0056] In this state, exposure processing is executed to transfer
the pattern formed on the mask M onto the wafer W.
[0057] The procedure of unloading the wafer after exposure
processing will be described next.
[0058] (STEP 5) The wafer that has undergone the exposure
processing is transferred into the load-lock chamber 5 by the
transfer mechanism (not shown) in the process chamber 3.
[0059] (STEP 6) The gate valve 6 on the process chamber 3 side is
closed, the exhaust switching valve 22 is switched to air
circulation, and the supply switching valve 20 is switched to the
clean booth side. After that, air is fed into the load-lock chamber
5 to restore the atmospheric pressure. In this state, a laminar
flow of air is formed in the load-lock chamber 5 (FIG. 2B).
[0060] (STEP 7) When the pressure in the load-lock chamber 5 equals
that in the clean booth 14, the gate valve 7 on the outer air side
is opened, and the wafer is transferred to the coater/developer 8
by the transfer mechanism 9.
[0061] FIG. 3 is a view showing a modification to the first
embodiment. In this modification, a wafer is loaded/unloaded
to/from the reduced-pressure processing apparatus using a transfer
container 30 which stores a wafer carrier 31 and is filled with
clean air. The clean booth 14 has an elevating mechanism 32 for
loading/unloading the wafer carrier 31 to/from the clean booth
14.
[0062] FIG. 4 is a view showing the second embodiment of the
present invention. In this case, a load-lock chamber 5 is opened to
outer air using dry nitrogen as a dry gas. A clean booth 44 has one
surface connected to a gate valve 7 of the load-lock chamber 5 on
the outer air side and the other surface connected to a
coater/developer 8 and covers the wafer transfer path. A filter 45
is provided under the entire upper surface of the clean booth 44.
The clean booth 44 is open, and a fan unit 49 is arranged on the
upper side of the clean booth 44. Air is supplied from the upper
side to the clean booth 44 by the fan unit 49 through the filter 45
and exhausted outside from the lower side of the clean booth 44.
With this arrangement, a laminar flow of clean air with high
cleanliness is formed in the full range of the wafer transfer
path.
[0063] A supply pipe 19 has one end connected to the load-lock
chamber 5 and the other end connected to a process chamber 3 and
dry nitrogen supply source 61 through a supply switching valve 50.
By the supply switching valve 50, one of three states can be
selected: 1) a state wherein no gas is supplied into the load-lock
chamber 5, 2) a state wherein helium is supplied into the load-lock
chamber 5 through the supply pipe 19 (state wherein the valve is
opened to the "process chamber side"), or 3) a state wherein dry
nitrogen is supplied into the load-lock chamber 5 through the
supply pipe 19 (state wherein the valve is opened to the "nitrogen
side"). In addition, by a flow rate adjusting valve 62, the flow
rate of nitrogen can be adjusted such that a predetermined pressure
is set in the load-lock chamber 5.
[0064] One end of an exhaust pipe 51 is connected to the load-lock
chamber 5, and the other end is connected to an exhaust mechanism
53 and helium circulation unit 12 through an exhaust switching
valve 52. By the exhaust switching valve 52, one of two states can
be selected: 1) a state wherein the gas is exhausted from the
load-lock chamber 5 through the exhaust pipe 51 by the exhaust
mechanism 53 ("exhaust"), or 2) a state wherein helium is
circulated through the load-lock chamber 5 ("helium
circulation").
[0065] The process chamber 3, X-ray window 4, load-lock chamber 5,
gate valves 6 and 7, coater/developer 8, and transfer mechanism 9
denoted by the same reference numerals as in the first embodiment
have the same arrangements as in the first embodiment, and a
detailed description thereof will be omitted.
[0066] (STEP 0) First, a laminar flow of helium is formed in the
process chamber 3 in accordance with the same procedures as in the
first embodiment. At this time, the gate valve 6 on the process
chamber 3 side is kept closed, and the gate valve 7 on the outer
air side (clean booth 44 side) is kept open. The supply switching
valve 50 is switched to the nitrogen side, and the exhaust
switching valve 52 is switched to the exhaust mechanism 53 side,
thereby forming a laminar flow of clean dry nitrogen in the
load-lock chamber 5.
[0067] (STEP 1) A wafer coated with a resist by the
coater/developer 8 is sent into the load-lock chamber 5 by the
transfer mechanism 9.
[0068] (STEP 2) The gate valve 7 on the outer air side (clean booth
44 side) and the supply switching valve 50 are closed and the
load-lock chamber 5 is exhausted to 0.1 Torr. After that, the
exhaust switching valve 52 is switched to helium circulation.
[0069] (STEP 3) The supply switching valve 50 is switched to the
process chamber side. At this time, a decrease in pressure in the
process chamber 3 can be compensated with helium by the helium
supply mechanism (not shown), as needed. In this state, a laminar
flow of helium is formed in the load-lock chamber 5, as in the
process chamber 3.
[0070] (STEP 4) When the pressure in the load-lock chamber 5 equals
that in the process chamber 3, the gate valve 6 on the process
chamber 3 side is opened, and the wafer is transferred into the
process chamber 3 by the transfer mechanism (not shown) in the
process chamber 3.
[0071] In this state, exposure processing is executed to transfer a
pattern formed on a mask M onto a wafer W.
[0072] The procedure of unloading the wafer after exposure
processing will be described next.
[0073] (STEP 5) The wafer that has undergone the exposure
processing is transferred into the load-lock chamber 5 by the
transfer mechanism (not shown) in the process chamber 3.
[0074] (STEP 6) The gate valve 6 on the process chamber side is
closed, the supply switching valve 50 is switched to the nitrogen
side, and the exhaust switching valve 52 is switched to the exhaust
mechanism 53 side. Nitrogen is supplied while adjusting the flow
rate by the flow rate adjusting valve 62 until the atmospheric
pressure is restored in the load-lock chamber 5.
[0075] (STEP 7) When the pressure in the load-lock chamber 5 equals
that in the clean booth 44, the gate valve 7 on the outer air side
(clean booth 44 side) is opened, and the wafer is transferred to
the coater/developer 8 by the transfer mechanism 9.
[0076] In the first and second embodiments, a reduced-pressure
processing apparatus suitable for an X-ray exposure apparatus has
been described. The arrangement can also be applied to any other
processing apparatus for processing a sample in a predetermined
atmosphere.
[0077] In the first and second embodiments, the clean booth and
load-lock chamber are connected through a gate valve. However, the
load-lock chamber may be connected to the clean booth by partially
inserting the load-lock chamber into the clean booth.
[0078] In the first and second embodiments, a filter capable of
removing particles and chemical components is used. However, a
filter capable of removing either particles or chemical components
may be used. In the first and second embodiments, a straightening
plate is used. However, only the filter may be used.
[0079] In the first and second embodiments, the load-lock chamber
is opened to outer air using air or nitrogen. However, any other
gas may be used depending on the situation.
[0080] In the first and second embodiments, one load-lock chamber
is prepared in correspondence with one process chamber. However,
two or more load-lock chambers may be provided for one process
chamber. In this case, each load-lock chamber preferably has a
clean booth that covers a transfer mechanism for
transferring/receiving a sample such as a substrate to/from the
load-lock chamber.
[0081] In the first and second embodiments, one clean booth is
prepared in correspondence with one load-lock chamber. However, two
or more clean booths each of which covers a transfer mechanism for
transferring/receiving a sample such as a substrate to/from the
load-lock chamber may be provided for one load-lock chamber. In
this case, a sample such as a substrate may be transferred to the
load-lock chamber by the transfer mechanism in the first clean
booth, and the sample such as a substrate in the load-lock chamber
may be received by the transfer mechanism in the second clean
booth.
[0082] According to the first and second embodiments, a laminar
flow of a clean gas is formed in the reduced-pressure process
chamber, and a clean booth connected to a load-lock chamber is
installed on the transfer path in outer air. Hence, the cleanliness
in the entire factory clean room need not be strictly managed, and
the cost can be largely reduced. In addition, the maintenance does
not adversely affect other apparatuses.
[0083] When a circulation unit and filter are provided in the
process chamber, and the gas in the process chamber is circulated
to form a laminar flow, ambient gas consumption can be reduced, and
the cost reduction can be promoted.
[0084] When the ambient gas in the process chamber or the gas in
the clean booth is selectively supplied depending on the state of
the load-lock chamber, the cleanliness can be improved by a simple
mechanism without independently preparing a cylinder (bomb) or
filter.
[0085] When the ambient gas in the process chamber or dry nitrogen
is selectively supplied depending on the state of the load-lock
chamber, moisture mixing into the load-lock chamber can be
suppressed, contamination of the substrate to be processed can be
prevented, and the vacuum suction time can be shortened.
[0086] An embodiment of a device manufacturing method will be
described next. FIG. 5 shows the flow of manufacturing a
semiconductor device (e.g., a semiconductor chip such as an IC or
an LSI, a liquid crystal panel, or a CCD). In step 1 (circuit
design), the pattern of a semiconductor device is designed. In step
2 (mask preparation), a mask (reticle) as a master having the
designed pattern is prepared. In step 3 (wafer manufacture), a
wafer as a substrate is manufactured using a material such as
silicon. In step 4 (wafer process) called a preprocess, an actual
circuit is formed on the wafer by lithography using the prepared
mask and wafer. In step 5 (assembly) called a post-process, a
semiconductor chip is formed from the wafer prepared in step 4.
This step includes processes such as assembly (dicing and bonding)
and packaging (chip encapsulation). In step 6 (inspection),
inspections including operation check test and durability test of
the semiconductor device manufactured in step 5 are performed. A
semiconductor device is completed with these processes and shipped
(step 7).
[0087] FIG. 6 is a flow chart showing the detailed flow of the
wafer process. In step 11 (oxidation), the surface of the wafer is
oxidized. In step 12 (CVD), an insulating film is formed on the
wafer surface. In step 13 (electrode formation), an electrode is
formed on the wafer by deposition. In step 14 (ion implantation),
ions are implanted into the wafer. In step 15 (resist process), a
photosensitive agent is applied to the wafer. In step 16
(exposure), the circuit pattern of the mask is printed on the wafer
by exposure using the above X-ray exposure apparatus. In step 17
(development), the exposed wafer is developed. In step 18
(etching), portions other than the developed resist image are
etched. In step 19 (resist removal), any unnecessary resist
remaining after etching is removed. By repeating these steps, a
multilayered structure of circuit patterns is formed on the wafer.
When the manufacturing method of this embodiment is used, a
semiconductor device with high degree of integration, which is
conventionally difficult to manufacture, can be manufactured.
[0088] According to the present invention with the above-described
arrangements, the following effects can be obtained.
[0089] A laminar flow of clean air is formed in the transfer path
for a wafer such as a substrate to be processed up to the load-lock
chamber to prevent dust from sticking to the substrate to be
processed, thereby the required cleanliness in the entire clean
room can be reduced, and the facility and maintenance cost can be
largely reduced.
[0090] Use of a semiconductor manufacturing apparatus for
processing a wafer by processing apparatus in a predetermined
atmosphere can contribute to cost reduction of a semiconductor
device and the like.
[0091] As many apparently widely different embodiments of the
present invention can be made without departing from the spirit and
scope thereof, it is to be understood that the invention is not
limited to the specific embodiments thereof except as defined in
the appended claims.
* * * * *