U.S. patent application number 12/606569 was filed with the patent office on 2010-04-29 for vacuum exhaust method and a substrate processing apparatus therefor.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. Invention is credited to Hidefumi MATSUI, Tsuyoshi Moriya, Nobuyuki Nagayama.
Application Number | 20100104760 12/606569 |
Document ID | / |
Family ID | 42117773 |
Filed Date | 2010-04-29 |
United States Patent
Application |
20100104760 |
Kind Code |
A1 |
MATSUI; Hidefumi ; et
al. |
April 29, 2010 |
VACUUM EXHAUST METHOD AND A SUBSTRATE PROCESSING APPARATUS
THEREFOR
Abstract
A vacuum exhaust method of a substrate processing apparatus,
after opening to the atmosphere, depressurizes a vacuum processing
chamber having therein a mounting table for mounting a target
substrate thereon. The vacuum exhaust method includes covering a
surface of the mounting table with a protection member; sealing the
vacuum processing chamber; vacuum evacuating the sealed vacuum
processing chamber; and adsorbing at least one of foreign
substances and out-gases by the protection member.
Inventors: |
MATSUI; Hidefumi; (Nirasaki
City, JP) ; Moriya; Tsuyoshi; (Tokyo, JP) ;
Nagayama; Nobuyuki; (Nirasaki City, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND MAIER & NEUSTADT, L.L.P.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
TOKYO ELECTRON LIMITED
Tokyo
JP
|
Family ID: |
42117773 |
Appl. No.: |
12/606569 |
Filed: |
October 27, 2009 |
Current U.S.
Class: |
427/294 ;
118/50 |
Current CPC
Class: |
B08B 7/04 20130101; C23C
16/4401 20130101; C23C 16/4412 20130101; B08B 7/0035 20130101; B08B
6/00 20130101; B08B 5/04 20130101 |
Class at
Publication: |
427/294 ;
118/50 |
International
Class: |
B05D 7/00 20060101
B05D007/00; B05C 11/00 20060101 B05C011/00 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 27, 2008 |
JP |
2008-276026 |
Claims
1. A vacuum exhaust method of a substrate processing apparatus
including a vacuum processing chamber having therein a mounting
table for mounting a target substrate thereon, the vacuum exhaust
method comprising: opening the vacuum processing chamber to the
atmosphere; covering a surface of the mounting table with a
protection member; sealing the vacuum processing chamber; vacuum
evacuating the sealed vacuum processing chamber; and adsorbing at
least one of foreign substances and out-gases by the protection
member.
2. The vacuum exhaust method of claim 1, wherein said vacuum
evacuating includes cooling the protection member to exert a
thermophoretic force on a foreign substance being adsorbed in the
protection member.
3. The vacuum exhaust method of claim 1, wherein the vacuum
evacuating includes charging the protection member to apply an
electrostatic force to a foreign substance being adsorbed in the
protection member.
4. The vacuum exhaust method of claim 1, wherein after the vacuum
evacuating, the protection member is accommodated in a waiting
chamber outside the vacuum processing chamber, and before vacuum
evacuating the vacuum processing chamber again, the protection
member is unloaded from the waiting chamber and loaded in the
vacuum processing chamber.
5. The vacuum exhaust method of claim 4, further comprising
regenerating an used protection member in the waiting chamber.
6. The vacuum exhaust method of claim 5, wherein said regenerating
includes blowing a gas or an aerosol to the used protection member
to remove said at least one of the foreign substances and the
out-gases adsorbed in the protection member.
7. The vacuum exhaust method of claim 5, wherein said regenerating
includes heating the used protection member to exert a
thermophoretic force on the foreign substances adsorbed in the
protection member so that the foreign substances are detached from
the protection member.
8. The vacuum exhaust method of claim 7, wherein said heating
includes applying an ultrasonic wave to the protection member to
vibrate a surface of the protection member.
9. The vacuum exhaust method of claim 7, wherein the heating
includes irradiating light onto the protection member to cause
thermal vibration or energy vibration to vibrate a surface of the
substrate.
10. A substrate processing apparatus comprising: a mounting table
for mounting a target substrate thereon; a vacuum processing
chamber in which the mounting table is provided; an exhaust unit
for evacuating the vacuum processing chamber; and an adsorption
layer coating a surface of the mounting table and, during
evacuating the vacuum processing chamber, adsorbing at least one of
foreign substances and out-gases.
11. The substrate processing apparatus of claim 10, wherein the
adsorption layer is a layer of a mesh structure made of inorganic
fibers, or a woven or a nonwoven fabric structure.
12. The substrate processing apparatus of claim 10, wherein the
adsorption layer is formed of mesh-structured activated carbon, or
a woven or a nonwoven fabric-structured carbon fibers.
13. The substrate processing apparatus of claim 10, wherein the
adsorption layer includes a resin sheet layer on its backside
surface.
14. A substrate processing apparatus comprising: a vacuum
processing chamber; a mounting table provided in the vacuum
processing chamber to mount a target substrate thereon; an exhaust
unit for depressurizing an interior of the vacuum processing
chamber; a protection member that, during vacuum evacuation of the
interior of the vacuum processing chamber by the exhaust unit,
covers a surface of the mounting table, and, after vacuum
evacuation by the exhaust unit, is moved to the outside of the
vacuum processing chamber for waiting; and an waiting chamber for
accommodating the protection member outside of the vacuum
processing chamber.
15. The substrate processing apparatus of claim 14, further
comprising a regeneration unit provided in the waiting chamber to
regenerate an used protection member.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application claims the benefit of priority to Japanese
Patent Application No. 2008-276026, filed on Oct. 27, 2008, the
entire contents of which are incorporated herein by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a vacuum exhaust method and
a substrate processing apparatus therefor; and more particularly,
to a vacuum exhaust method that vacuum-exhausts a vacuum processing
chamber of a substrate processing apparatus.
BACKGROUND OF THE INVENTION
[0003] In a substrate processing apparatus such as a plasma ashing
apparatus or a CVD (Chemical Vapor Deposition) apparatus for
performing a required process on a substrate, e.g., a semiconductor
substrate, a flat panel display substrate, or the like, there is
known that when a vacuum processing chamber is evacuated to vacuum
after maintenance accompanied by opening to the atmosphere,
particle contamination is caused by, e.g., dispersion of
particles.
[0004] The attachment of particles onto parts included in the
chamber contaminates a substrate (hereinafter, referred to as
"wafer") in subsequent processes or makes it difficult for the
wafer to be adsorbed on a surface of a mounting table. This may
cause a process failure or abnormal discharge.
[0005] If the interior of the chamber is evacuated while a wafer is
mounted on the mounting table (hereinafter, referred to as "stage")
and if mapping measurement is made after evacuation for particles
attached on a surface of the wafer, a particle map is often
observed which duplicates the array of gas holes of a shower head
disposed to face the stage. From the above observation, it can be
seen that, during evacuation, particles are dispersed from the gas
holes of the shower head and attached onto the stage. Such
particles in the chamber may be originated from particles entered
from the external environment into the chamber during maintenance,
particles remaining in a gas line, particles generated by
condensation of moisture, and the like.
[0006] Furthermore, it is known that gases are released or
outgassed from parts included in the chamber during evacuation. The
out-gases do not only prolong an evacuation time needed to lower
the inner pressure of the chamber down to a required vacuum level,
but also cause problems such as process variation, abnormal
discharge, or the like. The term "out-gases" used herein refers to
gases released or outgassed from parts inside the processing
chamber during vacuum evacuating thereof.
[0007] FIG. 13 illustrates a relationship between an amount of a
species in out-gases generated from parts included in a chamber of
a substrate processing apparatus and a release time thereof.
[0008] It can be seen from FIG. 13 that the species in the
out-gases may include N.sub.2/CO, O.sub.2, and CO.sub.2 in addition
to moisture (H.sub.2O), which have been entered from the external
environment when the chamber was opened to the atmosphere. It can
also be seen that the amount of released moisture is greater by at
least one order of magnitude than the amount of the other released
species, and thus main species of the out-gases is moisture. An
alumite based material, thermally sprayed yttria based material,
ceramics based material, carbon based material, or the like may be
considered as a material that releases a great amount of
out-gases.
[0009] There is known a technology of reducing particles generated
in the chamber of the substrate processing apparatus during chamber
evacuation (see, e.g., Japanese Patent Laid-open Application No.
1996-255784). The patent application supra discloses a vacuum
processing method for use in an apparatus provided with a wafer
stage for mounting thereon a wafer at a bottom portion of a vacuum
processing chamber; a wafer stage cover for vacuum-sealing the
interior of the vacuum processing chamber; a gas inlet line for
introducing a gas into the sealed vacuum processing chamber that is
formed by the wafer stage and the wafer stage cover; and a vacuum
exhaust line for performing evacuation. In the vacuum processing
method, the gas is injected from the gas inlet line to the wafer
mounted on the wafer stage to blow particles off the wafer and then
the particles are sucked through the vacuum exhaust line.
[0010] In the above prior art, the gas is injected toward the wafer
to blow particles off the wafer, and then the particles are
exhausted through the vacuum exhaust line. However, the blown
particles may be attached to and remain on other parts included in
the chamber so that particles may not be removed completely.
Therefore, there is a need for a technology that can effectively
collect particles present in the chamber and introduced into the
chamber during evacuation, and adsorb out-gases generated during
evacuation to remove the particles and the out-gases.
SUMMARY OF THE INVENTION
[0011] In view of the above, the present invention provides vacuum
evacuating method and a substrate processing apparatus therefor,
which can adsorb and remove particles and out-gases generated in a
chamber during vacuum evacuation.
[0012] In accordance with a first aspect of the present invention,
there is provided a vacuum exhaust method of a substrate processing
apparatus including a vacuum processing chamber having therein a
mounting table for mounting a target substrate thereon, the vacuum
exhaust method including opening the vacuum processing chamber to
the atmosphere; covering a surface of the mounting table with a
protection member; sealing the vacuum processing chamber; vacuum
evacuating the sealed vacuum processing chamber; and adsorbing at
least one of foreign substances and out-gases by the protection
member.
[0013] In accordance with a second aspect of the present invention,
there is provided a substrate processing apparatus including a
mounting table for mounting a target substrate thereon; a vacuum
processing chamber in which the mounting table is provided; an
exhaust unit for evacuating the vacuum processing chamber; and an
adsorption layer coating a surface of the mounting table and,
during evacuating the vacuum processing chamber, adsorbing at least
one of foreign substances and out-gases.
[0014] In accordance with a third aspect of the present invention,
there is provided a substrate processing apparatus including a
vacuum processing chamber; a mounting table provided in the vacuum
processing chamber to mount a target substrate thereon; an exhaust
unit for depressurizing an interior of the vacuum processing
chamber; a protection member that, during vacuum evacuation of the
interior of the vacuum processing chamber by the exhaust unit,
covers a surface of the mounting table, and, after vacuum
evacuation by the exhaust unit, is moved to the outside of the
vacuum processing chamber for waiting; and an waiting chamber for
accommodating the protection member outside of the vacuum
processing chamber.
BRIEF DESCRIPTION OF THE DRAWINGS
[0015] The objects and features of the present invention will
become apparent from the following description of preferred
embodiments, given in conjunction with the accompanying drawings,
in which:
[0016] FIG. 1 is a view schematically illustrating a configuration
of a substrate processing apparatus in accordance with an
embodiment of the present invention;
[0017] FIG. 2 is a side view of a protection member;
[0018] FIG. 3 is a view illustrating a variation of the protection
member shown in FIG. 2;
[0019] FIG. 4 is a view illustrating another variation of the
protection member shown in FIG. 2;
[0020] FIG. 5 is a view illustrating still another variation of the
protection member shown in FIG. 2;
[0021] FIG. 6 schematically illustrates an arrangement relationship
between a vacuum processing chamber vacuum and a waiting chamber
which is provided adjacent to the processing chamber and serves as
an area for accommodating a protection member;
[0022] FIG. 7 is an explanatory diagram illustrating an example of
protection member regenerating unit provided in the waiting
chamber;
[0023] FIG. 8 is an explanatory diagram illustrating another
example of protection member regenerating unit provided in the
waiting chamber;
[0024] FIG. 9 is an explanatory diagram illustrating still another
example of protection member regenerating unit provided in the
waiting chamber;
[0025] FIG. 10 is an explanatory diagram illustrating yet still
another example of protection member regenerating unit provided in
the waiting chamber;
[0026] FIG. 11 is an explanatory diagram illustrating a further
example of protection member regenerating unit provided in the
waiting chamber;
[0027] FIG. 12 schematically shows a configuration of an example of
a substrate processing system; and
[0028] FIG. 13 is a view illustrating a relationship between an
amount of species in out-gases and a release time thereof, the
out-gases being generated from parts included in a chamber of a
substrate processing apparatus during vacuum evacuation.
DETAILED DESCRIPTION OF THE EMBODIMENTS
[0029] Hereinafter, embodiments of the present invention will be
described in more detail with reference to accompanying drawings
which forms a part hereof.
[0030] FIG. 1 is a view schematically illustrating a substrate
processing apparatus in accordance with an embodiment of the
present invention.
[0031] Referring to FIG. 1, the substrate processing apparatus 10
includes a chamber (processing chamber) 11; a mounting table
(stage) 12 arranged in the chamber 11 to mount a wafer W thereon;
an enclosure 13 arranged along the circumference of the stage 12; a
focus ring 14 and a cover ring 15 provided on top of the enclosure
13 and an outer peripheral portion of the stage 12 in a manner that
they surround the wafer W (not shown); a ceiling member (shower
head) 16 arranged at the upper portion of the chamber 11 opposite
to the stage 12; sidewall member 17 of the chamber; a sidewall
member 19 of the stage 12; and a shutter 18 provided at a transfer
port through which the wafer W is loaded and unloaded into and from
the chamber 11.
[0032] A gas exhaust path 20 is provided between the sidewall
member 19 of the stage 12 and the sidewall member 17 of the chamber
11, and connected to a TMP (Turbo Molecular Pump) 22 via a gas
exhaust plate 21. Further, an APC (Adaptive Pressure Control) valve
23 which is of a variable butterfly valve is provided between the
chamber 11 and the TMP 22 to control a pressure in the chamber 11.
The TMP 22 exhausts a gas or the like from the interior of the
chamber 11.
[0033] In the above substrate processing apparatus when, e.g., an
ashing process is performed on the wafer W, vacuum evacuation is
first performed to depressurize the interior of the chamber down to
a required pressure of, e.g., 1.3 Pa (10 mTorr). At this time, a
surface of the stage 12 and a surface of a sidewall member 17 are
covered by protection members 25 to be protected from particles P
generated in the chamber.
[0034] In FIG. 1, the surface of the stage 12 which mounts the
wafer W thereof is covered by a protection member 25 whose area is
larger than that of the surface of the stage 12 (i.e., the diameter
of the protection member 25 being greater than that of the stage
12). A surface of the sidewall member 17 that is a part included in
the chamber is covered by a protection member 25 as well.
[0035] FIG. 2 shows a side view of a protection member 25.
[0036] Referring to FIG. 2, the protection member 25 is a
plate-shaped or sheet-shaped member that adsorbs and captures
particles P dispersed from, e.g., gas holes of the shower head 16
during vacuum evacuation. The protection member 25 includes a base
portion 26, a trap portion 27 provided on the top surface of the
base portion 26 to serve as a foreign substance adsorption layer,
and an adsorption portion 28 provided on the rear surface of the
base portion 26.
[0037] The trap portion 27 is formed to have, e.g., a knitted mesh
structure, or a woven or a nonwoven fabric structure made of
fibers, e.g., silica, alumina, or a mixture thereof. As for the
mixture of silica and alumina, a mixing ratio is, e.g., 7:3. The
mesh structure, or the woven or the nonwoven fabric structure
allows the particles P entering into the trap portion to collide
with fibrous tissues several times and consume their kinetic
energies, thereby enabling the particles P to be easily
captured.
[0038] The base portion 26 is made of a material, e.g., quartz,
silicon, or the like, that hardly outgases. Further, it is not
desirable to adopt Cu or the like as the material constituting the
base portion 26 because such material may cause contamination in
the wafer W.
[0039] The adsorption portion 28 on the rear surface of the base
portion 26 is made of an adhesive or adsorptive resin sheet such as
a polyimide sheet. The adsorption portion 28 contacts a surface of
a member to be protected, e.g., the stage 12 and adsorbs and
detaches particles attached thereon. An adhesive surface (rear
surface) of the adsorption portion 28 is formed to have an uneven
surface that is conformal to the shapes of the top surface of stage
12 and surfaces of the focus ring 14 and the cover ring 15
surrounding the top surface of the stage 12 to thereby be in tight
contact therewith.
[0040] The top surface of the stage 12 and the surface of the
sidewall member 17 are covered by the protection members 25
configured as described above. And then, the vacuum evacuation is
performed by, e.g., closing a shutter 18, activating the TMP 22,
and exhausting the gases from the interior of the chamber 11 via
the gas exhaust plate 21. At this time, particles P introduced into
the chamber 11 from the gas holes (not shown) of the shower head
16, they collide with and are captured by the trap portion 27 of
each of the protection members 25 arranged to cover the top surface
of the stage 12 and the surface of the sidewall member 17.
[0041] With this embodiment, particles P generated during vacuum
evacuation can be captured by the trap portions 27 of each of the
protection members 25 disposed on the top surface of stage 12 and
to cover the surface of the sidewall member 17. Therefore, it is
possible to prevent particle contamination that may occur during
vacuum evacuation and stabilize subsequent processes.
[0042] Moreover, since a self-cleaning effect can be achieved in
the inside of the substrate processing apparatus 10, apparatus
assembling or maintenance accompanied by opening to the atmosphere,
which conventionally needed to be performed in a clean room at a
high degree of cleanness, may be carried out at a lower degree of
cleanness.
[0043] In the present embodiment, the members included in the
chamber (referred to as "in-chamber members" herein after) which
are covered by the protection members 25 are not limited to the
stage 12 and the sidewall member 17, but may include other members,
e.g., the sidewall member 19 of the stage 12, a shield ring, and
the like, which are needed to be protected from the attachment of
particles P.
[0044] Further, in the embodiment, the trap portion 27 of the
protection member 25 may be formed in a multi-layer structure. With
this configuration, when adsorptive power of a first trap layer
adsorbing the particles P is weakened, the first trap layer is
detached to allow a second trap layer to be exposed and used. As
such, the trap portion 27 may be configured to have multiple trap
layers that may be sequentially detached and used.
[0045] In the embodiment, it may be preferable that the gap between
the protection member 25 and the in-chamber members to be protected
thereby, e.g., the top surface of the stage 12 made to be smaller.
The protection member 25 is disposed directly on the stage 12 by
using, e.g., an arm mechanism. Thus, it is possible to avoid
contamination due to particles P entering in between the protection
member 25 and the top surface of the stage 12. Further, although it
can be considerable that the protection member 25 is contact with
the stage 12, the protection member 25 may be preferably made not
to be in contact with the stage 12.
[0046] In the embodiment, the protection member 25 may also have a
cooling function.
[0047] FIG. 3 illustrates a variation of the protection member 25
shown in FIG. 2.
[0048] Referring to FIG. 3, a protection member 30 includes a
cooling adsorption portion 29 which is formed by embedding, e.g., a
peltier element 31 serving as a cooling unit in the adsorption
portion 28 shown in FIG. 2.
[0049] The protection member 30 thus configured is arranged to
cover the top surface of the stage 12 in the chamber 11. Then, the
vacuum evacuation is performed while the cooling adsorption portion
29 is being cooled such that the temperature difference between the
cooling adsorption portion 29 and the interior of the chamber is,
e.g., 0.degree. C. to -20.degree. C. As a result, a temperature
difference occurs between particles P generated during vacuum
evacuation and the trap portion 27 cooled by the cooling adsorption
portion 29 of the protection member 30 and a thermophoretic force
is exerted on the particles P such that the particles P are pulled
toward the trap portion 27 of the protection member 30.
Accordingly, the efficiency of capturing the particles P by the
trap portion 27 is improved.
[0050] The thermophoretic force is used herein may be defined as
follows. When a large temperature gradient occurs in a space where
particles exist, a momentum of gaseous molecules colliding with the
particles increases at a high temperature side in comparison with a
low temperature side. That is, particles are subjected to a force
oriented from the high temperature side to the low temperature
side. Such a force as exerted on the particles is called
"thermophoretic force".
[0051] Alternatively, the efficiency of capturing the particles P
may be improved by charging the protection member.
[0052] FIG. 4 shows a variation of the protection member 25 shown
in FIG. 2.
[0053] Referring to FIG. 4, a protection member 35 has a charging
adsorption portion 32 instead of the adsorption portion 28 included
in the protection member 25 shown in FIG. 2. The charging
adsorption portion 32 is electrically connected to, e.g., a DC
power supply 33.
[0054] In this configuration, the protection member 35 having the
charging adsorption portion 32 is arranged to cover the top surface
of the stage 12 in the chamber 11. Thereafter, a positive or a
negative DC voltage is applied to the charging adsorption portion
32 of the protection member 35 so that its polarity becomes
opposite to that of particles electrically charged. Then, an
electrostatic force is exerted on the particles P, which leads to
enhancing capturing efficiency of particles P. At this time, the DC
voltage applied to the charging adsorption unit 32 ranges, e.g.,
from -5 kV to +5 kV.
[0055] In this embodiment, a porous member having an adsorption
function, such as an activated carbon layer, an alumina layer, or
the like, may be employed as the base portion 26 of each of the
protection members 25, 30, and 35. When the porous layer is adopted
as the base portion 26, out-gases released from the in-chamber
members during vacuum evacuation can be adsorbed. Each of the
protection members 25, 30, and 35 conducts two functions, i.e.,
capturing the particles by a trap portion 27 in the top surface and
adsorbing the out-gases by the base portion 26.
[0056] The out-gases are generally released from porous in-chamber
members which include yttria, ceramics, or the like.
[0057] In this embodiment, the trap portion 27 of the protection
member 25 may be made of a gas adsorption material to capture
particles and adsorb out-gases.
[0058] FIG. 5 is a view illustrating a variation of the protection
member 25 shown in FIG. 2.
[0059] Referring to FIG. 5, a protection member 40 includes a trap
portion 38 instead of the trap portion 27 of the protection member
25 shown in FIG. 2. The trap portion 38 is made of a porous member
having a large surface area, such as activated carbon, porous
ceramic, or the like, e.g., in a mesh structure to provide a gas
adsorptive function.
[0060] The protection member 40 thus configured is arranged to
cover the top surface of the stage 12 in the chamber 11. Thus,
particles P (solid) released from, e.g., gas holes of the shower
head and introduced into the chamber 11 and out-gases (molecules)
generated from in-chamber members during vacuum evacuation are
simultaneously captured and adsorbed by the trap portion 38 with a
gas adsorptive function and removed.
[0061] Since the trap portion 38 is formed of mesh-structured
activated carbon, or a woven or a nonwoven fabric-structured carbon
fibers, the foreign particles and the out-gases generated during
vacuum evacuation can be adsorbed and removed with high
efficiency.
[0062] In this embodiment, a waiting chamber is provided adjacent
to the processing chamber to which the protection member is
installed. Accordingly, when necessary, the protection member can
be loaded from the waiting chamber into the processing chamber, and
when unnecessary, the protection member may be withdrawn into the
waiting chamber.
[0063] Since the protection member can be withdrawn into the
waiting chamber after the vacuum evacuation, the subsequent
processes on the substrate are not be interfered by the protection
member.
[0064] FIG. 6 schematically illustrates a configuration of a
substrate processing system that includes a processing chamber
where a vacuum evacuation is performed and a waiting chamber that
is provided adjacent to the processing chamber and serves as an
area for accommodating a protection member.
[0065] Referring to FIG. 6, the substrate processing system
includes two process ships, each of which include a process module
61, a processing chamber 62 provided in the process module 61, a
load lock module 64 having a transfer arm 63 for loading a wafer W
into the processing chamber 62, a waiting chamber 65 for a
protection member 66 provided adjacent to the load lock module 64.
The substrate processing system further includes a loader module 53
serving as a common transfer chamber to which the two process ships
are connected, and a transfer arm 69 provided in the loader module
53 to pick up a wafer W from a hoop 68 and transfer it to a load
lock module 64.
[0066] In the substrate processing system thus configured, the
protection member 66, is transferred, when not used, for standby
from the processing chamber 62 to the waiting chamber 65 by the
transfer arm 63 provided in the load lock module 64. When used, the
protection member 66 is loaded from the waiting chamber 65 to the
processing chamber 62.
[0067] In this embodiment, a protection member regenerating unit
may be provided in the waiting chamber 65 to release particles P
and out-gases from the protection member 66 on which the particles
P and the out-gases are attached. Accordingly, the protection
member can be reused repeatedly.
[0068] FIG. 7 is a view illustrating an example of the protection
member regenerating unit provided in the waiting chamber.
[0069] Referring to FIG. 7, a heating table 72 is provided in a
waiting chamber 71 to heat a protection member 75 on which
particles P and out-gases are adsorbed. The heating table 72 has
therein an electric heater 73 which electrically connected to,
e.g., a DC power supply 74.
[0070] With this configuration, the protection member 75 on which
particles P and out-gases are adsorbed is loaded into the waiting
chamber 71 and is mounted on the heating table to be heated to,
e.g., 100.degree. C..about.150.degree. C. by the electric heater
73. When the protection member 75 is heated, the particles P
collected in a trap portion 77 thereof are also heated so that a
temperature gradient occurs in a space surrounding the particles P.
That is, the temperature gradient is generated such that the
temperature at the protection member side of the particles P (lower
side in FIG. 7) is high and that at the side of the particles P
opposite to the protection member (upper side in FIG. 7) is
low.
[0071] Due to such temperature gradient, a thermophoretic force is
exerted on the particles P, from the surface of the protection
member 75 at the higher temperature to at the lower temperature
above the protection member 75. Accordingly, the particles P are
detached from the surface of the trap portion 77 and released along
with the out-gases, thereby regenerating the protection member
75.
[0072] In this embodiment, an ultrasonic vibrating process may be
conducted as well when the heating process is performed in order to
regenerate the protection member.
[0073] FIG. 8 illustrates another example of protection member
regenerating unit which is applied in the waiting chamber.
[0074] The protection member regenerating unit shown in FIG. 8 is
different from the protection member regenerating unit shown in
FIG. 7 in that the heating table 72 is replaced with a heating and
vibrating table 82 in which an ultrasonic oscillator 86 and an
electric heater 83 are embedded.
[0075] With this configuration, an used protection member 85 is
transferred and mounted on the heating and vibrating table 82 in a
waiting chamber 81. Then, while the protection member 85 is being
heated to 100.degree. C. to 150.degree. C. by the electric heater
83 under a pressure of, e.g., 1.3 kPa (10 Torr) in the waiting
chamber, the protection member 85 is vibrated by an ultrasonic
oscillator 86. As a consequence, the particles P and the out-gases
are detached from the protection member 85, and the protection
member 85 is regenerated. The particles P and the out-gases
released in the waiting chamber 81 are subjected to vacuum
evacuation by a dry pump. Further, a gas adsorption mechanism, such
as Cryo pump or the like, may be separately provided.
[0076] When the ultrasonic vibrating process is conducted together
with the heating process, an adhesive force of the particles P onto
the protection member 85 may be smaller than when only the heating
process is performed. Accordingly, the particles P are easily
detached from the protection member 85, thereby improving
regeneration efficiency. A frequency of the ultrasonic wave
generated by the ultrasonic oscillator is, e.g., 1.about.100
kHz.
[0077] In this embodiment, when the protection member is
regenerated, a light irradiating process may be performed together
with the heating process.
[0078] FIG. 9 presents still another example of the protection
member regenerating unit provided in a waiting chamber. The
protection member regenerating unit shown in FIG. 9 is different
from the protection member regenerating unit shown in FIG. 7 in
that a light source 96 is further provided above and opposite to
the heating table 92 to irradiate a protection member 95 to be
processed.
[0079] In this configuration, the used protection member 95 is
mounted on top surface of a heating table 92. Then, while the
protection member 95 is heated in 100.degree. C..about.150.degree.
C. by an electric heater 93 under a pressure of, e.g., 1.3 kPa (10
Torr) in the waiting chamber, an electromagnetic wave whose
frequency is, e.g., 100 kHz is irradiated on a surface of the
protection member 95 by the light source 96. Accordingly, particles
P are detached from the protection member 95, thereby regenerating
the protection member 95.
[0080] With the above configuration that the heating process is
performed together with the light irradiating process, the
particles P attached on the trap portion 97 of the protection
member 95 is subjected to a micro vibration, thereby reducing an
adhesive force of the particles P to the trap portion 97. Thus, the
particles P can be easily detached from the protection member
95.
[0081] In this case, an infrared laser beam may be irradiated to
the particles P that are attached on the surface of the protection
member 95. As irradiated with the infrared laser light, the
particles P absorb the infrared light which makes thermal vibration
much stronger. Accordingly, an adhesive force of the particles P to
the protection member 95 is weakened such that the particles P can
be easily detached from the surface of the protection member
95.
[0082] Further, out-gases adsorbed onto the protection member also
can be easily detached from the surface of the protection member
95. The particles P and the out-gases detached from the protection
member 95 are subjected to vacuum evacuation by a dry pump
separately.
[0083] In this embodiment, short wavelength light, e.g., UV (Ultra
Violet) light or EUV (Extreme Ultra Violet) light may be irradiated
onto a surface of the protection member 95 by the light source 96.
As irradiated with the short wavelength light, the particles P are
vibrated by energy of the short wavelength light. Accordingly, an
adhesive force of the particles P to the protection member 95 is
weakened such that the particles P can be easily blown and detached
from the surface of the protection member 95. Further, the
out-gases adsorbed onto the protection member 95 can be easily
detached from the surface of the protection member 95.
[0084] In this embodiment, when the protection member is
regenerated, a gas inject process may be employed.
[0085] FIG. 10 illustrates yet still another example of the
protection member regenerating unit provided in a waiting
chamber.
[0086] Referring to FIG. 10, the protection member regenerating
unit is further provided with a gas inject nozzle 106 for spraying
a cleaning gas to a surface of a protection member 105.
[0087] With this configuration, a cleaning gas such as N.sub.2 gas,
Ar gas, CO.sub.2 gas, or the like is sprayed at a speed of 1000
ml/sec to a surface of the used protection member 105 loaded in the
waiting chamber, thereby detaching particles P from the surface of
the protection member 105. Further, if out-gases are adsorbed on
the protection member 105, the out-gases also are released such
that the protection member 105 is regenerated.
[0088] With the gas inject process, the particles P and the
out-gases collected and adsorbed on the protection member 105 can
be easily detached, thereby regenerating the protection member 105.
The particles P and the out-gases detached from the protection
member 105 are subjected to vacuum evacuation by a dry pump
separately.
[0089] In this embodiment, when the protection member is
regenerated, an aerosol inject process may be employed.
[0090] FIG. 11 shows yet still another example of the protection
member regenerating unit provided in a waiting chamber.
[0091] The protection member regenerating unit shown in FIG. 11 is
different from the protection member regenerating unit shown in
FIG. 10 in that an aerosol inject nozzle 116 is provided instead of
the gas inject nozzle 106. An aerosol refers to tiny liquid or
solid substances that float in gas, e.g., steam as a liquid aerosol
and CO.sub.2 blast as a solid aerosol.
[0092] With this configuration, an aerosol is sprayed from an
aerosol inject nozzle 116 onto a surface of the used protection
member 115 loaded in the waiting chamber 111, so that the particles
and the out-gases collected and adsorbed on the protection member
115 are detached therefrom, thereby regenerating the protection
member 115. The particles P and the out-gases detached from the
protection member 115 are subjected to vacuum evacuation by a dry
pump separately.
[0093] Further, when the aerosol inject process is applied, an
aerosol, e.g., steam or CO.sub.2 blast may be injected to a surface
of the used protection member 115, so that the particles P and the
out-gases collected and adsorbed on the protection member 115 are
detached from the protection member 115, thereby regenerating the
protection member 115.
[0094] In this embodiment, a shock wave of a gas may be employed.
That is, the shock wave is applied to the used protection member by
a well-known method, so that the collected particles P and
out-gases are detached and released.
[0095] In accordance with the embodiment of the present invention,
when the load lock module of the substrate processing system is
evacuated, the above-described protection member may be used to
prevent contamination of the transfer arm which is caused by the
particles P or the like generated during vacuum evacuation.
[0096] Another embodiment of the present invention will be
hereinafter described.
[0097] FIG. 12 schematically illustrates an example of
configuration of a substrate processing system.
[0098] Referring to FIG. 12, the substrate processing system
includes a transfer module 51 which is hexagonal in a plan view; a
plurality of process modules 52a to 52f arranged at a peripheral
portion of the transfer module 51; a rectangular loader module 53
that is disposed by the transfer module 51 and serves as a transfer
chamber; and load lock modules 57 and 58 arranged between the
transfer module 51 and the loader module 53 to connect
therebetween. The loader module 53 includes a transfer arm 54 and a
load port 56 arranged at a connection portion between the loader
module 53 and each hoop mounting tables 55.
[0099] In the substrate processing system thus configured, wafer
mounting tables 57c and 58c serving as wafer transfer members are
provided in the load lock modules 57 and 58, respectively, and are
overcoated by a protection member 25.
[0100] In the substrate processing system 50, while an inside of
the loader module 53 is maintained as an atmospheric pressure, an
inside of the transfer module 51 is maintained in a vacuum.
Therefore, each of the load lock modules 57 and 58 is provided with
a vacuum gate valve at a connection portion to which the transfer
module 51 is connected, and an atmospheric door valve at a
connection portion to which the loader module 53 is connected. Each
load lock modules serves as a preliminary vacuum transfer chamber
whose inner pressure can be adjusted. The load lock modules 57 and
58 are subjected to vacuum evacuation if necessary and, therefore,
the wafer mounting tables 57c and 58c are coated by a protection
member 59 in order to prevent contamination of the wafer mounting
tables due to particles P entering into the load lock modules
during vacuum evacuation.
[0101] With this embodiment, the wafer mounting tables 57c and 58c
which are wafer transfer members are coated by the protection
member 59 when the load lock modules 57 and 58 of the substrate
processing system 50 are evacuated. Accordingly, it is possible to
certainly prevent particles P generated during vacuum evacuation
from being attached onto the mounting tables 57c and 58c, and
resultant contamination of the mounting tables 57c and 58c.
[0102] In this embodiment, the protection member 59 may be
preferably formed as a plate that has the same shape as and whose
diameter is larger than that of a wafer mounted on each of the
wafer mounting tables 57c and 58c in order to entirely cover the
wafer, for example, the dimension of the protection member 59 may
be 10% larger than that of the wafer. The protection member 59 may
be of mesh-structured porous material made of, for example,
activated carbon to adsorb particles P generated in the load lock
modules 27 and 28 during vacuum evacuation and substantially
simultaneously adsorb out-gases generated from in-chamber members.
Accordingly, a time required for evacuating the load lock modules
27 and 28 can be prevented from being increased. Further, since the
protection member 59 does not interfere with transfer of the wafer
W, it does not need to be withdrawn after vacuum evacuation.
[0103] In the above-described embodiments, a substrate to be
processed is not limited to a wafer for a semiconductor device, but
may be various substrates used for LCDs (Liquid Crystal Displays)
or FPDs (Flat Panel Displays), photomasks, CD substrates, print
boards, or the like.
[0104] Further, characteristic configurations of the above
embodiments, e.g., structure and material of a foreign substance
adsorption layer and an out-gases adsorption layer included in the
protection member, an application of a cooling unit and a charging
unit, an application of violation to the wafer W by ultrasonic wave
or by light irradiation at the regeneration heating process of the
protection member, or the like may be applied independently or in a
combination of two or more thereof.
[0105] Moreover, in accordance with another aspect of the present
invention, there is provided a storage medium storing program codes
of software capable of implementing functions of each of the
above-mentioned embodiments, which is supplied to a system or
device whose computer (or CPU, MPU, etc.) may read and executes the
program codes stored in the storage medium.
[0106] In this case, the program codes themselves, which are read
from the storage medium, realize the functions of each of the
above-described embodiments, and the program codes and the storage
medium storing the program codes fall within a scope of the present
invention.
[0107] Further, the storage medium storing program codes may
include, for example, floppy (registered trademark) discs, hard
discs, magneto-optical discs, optical discs such as CD-ROMs, CD-Rs,
CD-RWs, DVD-ROMs, DVD-RAMS, DVD-RWs, DVD+RWs, or the like, magnetic
tapes, non-volatile memory cards, ROMs, and the like.
Alternatively, the program codes may be downloaded over a
network.
[0108] The functions of each of the above-described embodiments may
be implemented by executing the program codes read by the computer,
or by executing a part or all of actual processes by OS (Operating
System) operating in the computer based on commands of the program
codes.
[0109] The program codes read from the storage medium may be
written in a memory provided in a function extension board inserted
in the computer or a function extension unit connected to the
computer. Then, the functions of each of the above-described
embodiments may be implemented by allowing a CPU provided in the
extension board or extension unit to execute a part or all of
actual processes for an extension function based on commands of the
program codes.
[0110] While the invention has been shown and described with
respect to the embodiments, it will be understood by those skilled
in the art that various changes and modifications may be made
without departing from the scope of the invention as defined in the
following claims.
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