U.S. patent application number 10/086708 was filed with the patent office on 2002-06-27 for vacuum processing apparatus and a vacuum processing system.
Invention is credited to Kawahara, Hironobu, Suehiro, Mitsuru, Takahashi, Kazue, Watanabe, Katsuya, Yamamoto, Hideyuki.
Application Number | 20020081174 10/086708 |
Document ID | / |
Family ID | 17975670 |
Filed Date | 2002-06-27 |
United States Patent
Application |
20020081174 |
Kind Code |
A1 |
Kawahara, Hironobu ; et
al. |
June 27, 2002 |
Vacuum processing apparatus and a vacuum processing system
Abstract
The vacuum processing apparatus has an atmospheric loader having
a plurality of cassette tables and a transport unit for carrying
wafers, a vacuum loader equipped with vacuum wafer-processing
chambers and a vacuum transport chamber communicating with the
processing chambers via gate valves, and a locking unit provided
with a loading lock chamber and unloading lock chambers that have
gate valves for connecting the atmospheric transport unit and
vacuum transport chamber; wherein two etching chambers, formed by
UHF-ECR reactors, are arranged symmetrically with respect to an
axial line passing through the middle of the vacuum transport
chamber and locking unit, only at the opposite side of the locking
unit across the vacuum transport chamber, and at an acute angle
with respect to the vacuum transport chamber, and UHF-ECR antennas,
almost parallel to the foregoing axial line, are opened at the
opposite side to that of the vacuum transport chamber.
Inventors: |
Kawahara, Hironobu;
(Kudamatsu, JP) ; Suehiro, Mitsuru; (Kudamatsu,
JP) ; Takahashi, Kazue; (Kudamatsu, JP) ;
Yamamoto, Hideyuki; (Kudamatsu, JP) ; Watanabe,
Katsuya; (Kudamatsu, JP) |
Correspondence
Address: |
ANTONELLI TERRY STOUT AND KRAUS
SUITE 1800
1300 NORTH SEVENTEENTH STREET
ARLINGTON
VA
22209
|
Family ID: |
17975670 |
Appl. No.: |
10/086708 |
Filed: |
March 4, 2002 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10086708 |
Mar 4, 2002 |
|
|
|
09697324 |
Oct 27, 2000 |
|
|
|
Current U.S.
Class: |
414/217 |
Current CPC
Class: |
H01L 21/67196 20130101;
Y10S 414/139 20130101; H01L 21/6719 20130101; H01L 21/67207
20130101; Y10S 414/135 20130101; H01L 21/67201 20130101; H01L
21/67161 20130101 |
Class at
Publication: |
414/217 |
International
Class: |
B65G 049/07 |
Foreign Application Data
Date |
Code |
Application Number |
Oct 29, 1999 |
JP |
11-307997 |
Claims
What is claimed is:
1. Vacuum processing apparatus comprising: a vacuum chamber having
a side wall member and a top member for separating the vacuum
chamber from atmospheric condition, so as to provide a vacuum
condition therein, an inner unit inside said side wall member, and
a hinge unit for pivotally connecting an upper edge of said side
wall member and one end of said top member; and a water stand on
which a wafer is mounted in said vacuum chamber, said top member
being rotated about a shaft of said hinge so that all upper
portions of said wall are seen from a top view, whereby said inner
unit can be lifted off upwardly.
Description
[0001] This application is a Divisional application of application
Ser. No. 09/697,324, filed Oct. 27, 2000.
BACKGROUND OF THE INVENTION
[0002] The present invention relates to vacuum processing
apparatuses, and, more particularly, to a vacuum processing
apparatus suitable for providing samples, namely, silicon
substrates and the like, with single-wafer processing, such as
etching, CVD (chemical vapor deposition), spattering, ashing, or
rinsing, and to semiconductor manufacturing equipment using such a
vacuum processing apparatus.
[0003] Vacuum processing apparatuses for processing samples can be
broadly divided into a cassette block type and a vacuum processing
block type. The cassette block type has its front extending
longitudinally with respect to the bay passageway of semiconductor
manufacturing equipment and includes cassette-and-sample
orientation alignment units and atmospheric robots; whereas, the
vacuum processing block type has a loading lock chamber, an
unloading lock chamber, vacuum processing chambers, vacuum
post-processing chambers, vacuum pumps, vacuum robots, and the
like.
[0004] According to the abovementioned equipment, for a
corresponding vacuum processing apparatus, the samples within a
cassette are each carried from the cassette block to the loading
lock chamber of the vacuum processing block by an atmospheric
robot. The sample is further transferred from the loading lock
chamber to a processing chamber by a vacuum robot, and then, after
being set on an electrode structure, the sample undergoes plasma
etching or other similar processing. The sample, after being
processed, is transported to and further processed in a vacuum
post-processing chamber, as required.
[0005] Examples of vacuum processing apparatuses for etching
samples with plasma are disclosed in, for example, Patent
Disclosure Collection 1986--Official Gazette Issue No. 8153, Patent
Disclosure Collection 1988--Official Gazette Issue No. 133532,
Patent Disclosure Collection 1994--Official Gazette Issue No.
30369, Patent Disclosure Collection 1994--official Gazette Issue
No. 314729, Patent Disclosure Collection 1994--Official Gazette
Issue No. 314730, and U.S. Pat. Nos. 5,314,509 and 5,784,799.
[0006] Vacuum processing apparatus based on the above-identified
prior art has a concentric or rectangular arrangement of processing
chambers and loading/unloading lock chambers. For example, the
apparatus set forth in U.S. Pat. No. 5,314,509 has a vacuum robot
located near the center of the vacuum processing block, with three
processing chambers concentrically arranged around the robot and a
loading lock chamber and an unloading lock chamber provided between
the robot and the cassette block. Such apparatus has the problem
that the transport arms of the atmospheric robot and vacuum robot
have too wide a rotational angle range, and, thus, that the entire
apparatus requires a large floor space.
[0007] At the same time, the processing chambers, vacuum pumps, and
other piped/tubed units within the vacuum processing block of the
vacuum processing apparatus require periodic and non-periodic
maintenance, such as checking and repairing. Accordingly, around
the vacuum processing block there are usually provided access doors
to enable the maintenance of the loading lock chamber, unloading
lock chamber, processing chambers, vacuum robots, and various
piped/tubed units.
[0008] Conventional vacuum processing apparatus can handle samples
up to 8 inches (about 200 mm) in diameter and not more than about
250 mm in cassette width "Cw". Even this cassette dimension,
however, has the problem that a large floor space is required. In
addition, to allow for handling larger samples, such as 12 inches
(about 300 mm) in diameter "d", since carrier pods are required,
the cassette width "Cw" must be increased to about 350 mm and the
cassette block for storing multiple carrier pods must also be
increased in width. If the width of the vacuum processing block is
to be determined according to such width of the cassette block, the
entire vacuum processing apparatus will require a larger floor
space. For example, in the case of a cassette block capable of
accommodating four carrier pods, if the diameter "d" of the samples
is increased from the conventional 8 inches to 12 inches, cassettes
will absolutely need to be at least about 40 cm wide.
[0009] For general semiconductor manufacturing equipment, to ensure
that a large number of samples undergo various types of processing
at the same time, multiple sets of a vacuum processing apparatus
which carry out the same type of processing are located at one bay
and samples are carried between bays automatically or manually.
Since such manufacturing equipment requires a high degree of
cleanliness, the entire equipment is installed in a large
cleanroom. Increases in the dimensions of a vacuum processing
apparatus, associated with increases in sample diameter, result in
an increased cleanroom-occupied floor area, which in turn leads to
further increased construction costs for a cleanroom, which is
already high in construction costs. If multiple sets of a vacuum
processing apparatus occupying a large floor area are to be
installed in cleanrooms of the same area, the number of vacuum
processing apparatus sets or the spacing between each set of the
vacuum processing apparatus must be reduced. Reduction in the
number of vacuum processing apparatus sets installed in cleanrooms
of the same area will necessarily reduce the productivity of the
semiconductor manufacturing equipment and thus increase
semiconductor manufacturing costs. Reduction in the spacing between
each set of the vacuum processing apparatus results in shortage of
the maintenance space required for check and repair services,
thereby deteriorating the maintainability of the vacuum processing
apparatus significantly.
SUMMARY OF THE INVENTION
[0010] One object of the present invention is to provide a vacuum
processing apparatus that can minimize its manufacturing costs
while at the same time providing flexibility to increases in sample
diameter.
[0011] Another object of the present invention is to provide a
vacuum processing apparatus which is excellent in maintainability
and is flexible to increases in sample diameter.
[0012] Still another object of the present invention is to provide
a vacuum processing apparatus, such as semiconductor manufacturing
equipment, that can minimize its manufacturing costs while at the
same time provide flexibility to increases in sample diameter and
ensure a complement of vacuum processing apparatuses, and which
does not deteriorate maintainability.
[0013] The present invention is directed to a vacuum processing
apparatus having an atmospheric loader equipped with a plurality of
cassette tables arranged close to each other, and with a transport
unit for carrying wafers from or to the cassette tables, a vacuum
loader equipped with vacuum wafer-processing chambers and with a
vacuum transport chamber in communication with the processing
chambers via gate valves, and a locking unit that includes loading
and unloading lock chambers equipped with gate valves for
connecting the foregoing atmospheric transport unit and vacuum
transport chamber;
[0014] wherein two vacuum wafer-processing chambers, both formed by
a magnetized UHF-band electromagnetic wave radiation/discharge
reactor (hereinafter, referred to as the UHF-ECR reactor), have
side wall inner units and antennas so mounted as to permit
disassembly, and they are arranged symmetrically with respect to an
axial line passing through the middle of the vacuum transport
chamber and locking unit, only at the opposite side of the locking
unit across the vacuum transport chamber, and in such a manner that
the vacuum processing chambers form an acute angle with respect to
the vacuum transport chamber.
[0015] The present invention is directed to a vacuum processing
apparatus having an atmospheric loader equipped with a plurality of
cassette tables arranged close to each other, and with a transport
unit for carrying wafers from or to the cassette tables, a vacuum
loader equipped with vacuum wafer-processing chambers and with a
vacuum transport chamber in communication with the processing
chambers via gate valves, and a locking unit that includes loading
and unloading lock chambers equipped with gate valves for
connecting the foregoing atmospheric transport unit and vacuum
transport chamber;
[0016] wherein two vacuum wafer-processing chambers, both formed by
the UHF-ECR reactor, are arranged symmetrically with respect to an
axial line passing through the middle of the vacuum transport
chamber and locking unit, only at the opposite side of the locking
unit across the vacuum transport chamber, and at an acute angle
with respect to the vacuum transport chamber, and the antennas of
the UHF-ECR reactor are directed almost in parallel to the
aforementioned axial line and are opened at the opposite side of
the vacuum transport chamber.
[0017] The present invention is directed to a vacuum processing
apparatus having an atmospheric loader equipped with a plurality of
cassette tables arranged close to each other, and with a transport
unit for carrying wafers from or to the cassette tables, a vacuum
loader equipped with vacuum wafer-processing chambers and with a
vacuum transport chamber in communication with the processing
chambers via gate valves, and a locking unit with loading and
unloading lock chambers gate-valved for connecting the foregoing
atmospheric transport unit and vacuum transport chamber;
[0018] wherein two vacuum wafer-processing chambers, both formed by
the UHF-ECR reactor, have side wall inner units and antennas so
mounted as to permit disassembly, and are arranged symmetrically
with respect to an axial line passing through the middle of the
vacuum transport chamber and locking unit, only at the opposite
side of the locking unit across the vacuum transport chamber, and
at an acute angle with respect to the vacuum transport chamber, and
the aforementioned atmospheric loader, vacuum loader, and locking
unit are arranged into a T-shape.
[0019] The present invention is directed to a vacuum processing
system having multiple sets of vacuum processing apparatuses
arranged in parallel, each set of which further consists of an
atmospheric loader equipped with a plurality of cassette tables
arranged close to each other, and with a transport unit for
carrying wafers from or to the cassette tables, a vacuum loader
equipped with vacuum wafer-processing chambers and with a vacuum
transport chamber in communication with the processing chambers via
gate valves, and a locking unit that includes loading and unloading
lock chambers equipped with gate valves for connecting the
foregoing atmospheric transport unit and vacuum transport
chamber;
[0020] wherein two vacuum wafer-processing chambers, both formed by
the UHF-ECR reactor, are arranged symmetrically with respect to an
axial line passing through the middle of the vacuum transport
chamber and locking unit, only at the opposite side of the locking
unit across the vacuum transport chamber, and at an acute angle
with respect to the vacuum transport chamber, and the vacuum
processing apparatus sets arranged in parallel have all their
vacuum processing chambers arranged linearly.
[0021] According to the present invention, it is possible to
minimize increases in manufacturing costs, while at the same time
providing flexibility to increases in sample size, and to provide a
vacuum processing apparatus which is excellent in maintainability.
Also, incorporation of such vacuum processing apparatus into
semiconductor manufacturing equipment makes it possible to ensure
the complement of vacuum processing apparatus and minimize
manufacturing costs, while at the same time providing flexibility
to increases in sample size, and to supply semiconductor
manufacturing equipment whose maintainability does not
deteriorate.
[0022] Furthermore, according to the present invention, one portion
of the vacuum vessel constituting the processing chambers can be
constructed as a section that can be opened and closed, and when
this section directs the processing chambers upward, components can
be maintained in their physically stable status at the operator
side in an almost horizontal position by friction or by a securing
section. Accordingly, since the top of the processing chambers
opens in the direction of the maintenance area, maintenance
personnel can easily both access the processing chambers and
perform maintenance operations from the top. As a result, the
maintenance personnel can easily handle components during
maintenance, whereby maintainability is improved, which in turn
enables the realization of a plasma processing apparatus which is
excellent in maintainability and the ease of operations and
contributes to an improvement of the productivity.
BRIEF DESCRIPTION OF THE DRAWINGS
[0023] FIG. 1 is a conceptual diagram of an embodiment of a vacuum
processing system according to the present invention.
[0024] FIG. 2 is a conceptual diagram showing the basic
configuration of one example of a vacuum processing apparatus
according to the present invention.
[0025] FIG. 3 is a schematic diagram of a side view of the
apparatus shown in FIG. 2.
[0026] FIG. 4 is a diagram showing one maintenance mode of the
apparatus shown in FIG. 2.
[0027] FIG. 5 is cutaway perspective view showing the maintenance
status of one plasma etching apparatus according to the present
invention.
[0028] FIG. 6 is a cutaway perspective view showing the maintenance
status of another plasma etching apparatus according to the present
invention.
[0029] FIG. 7 is a cutaway perspective view showing the maintenance
status of still another plasma etching apparatus embodied according
to the present invention.
[0030] FIG. 8 is a diagram showing an embodiment of the present
invention where the full-flat open-structured vacuum vessel is
mounted in a plasma processing system.
DETAILED DESCRIPTION OF PREFERRED EMBODIMENTS
[0031] Embodiments of the present invention will be described
hereunder with reference to the accompanying figures.
[0032] FIG. 1 shows a connected arrangement of three sets of vacuum
processing apparatus 10, which represents one embodiment of the
present invention. The three apparatus sets are shown as 10A, 10B,
and 10C.
[0033] Prior to description of the vacuum processing system shown
in FIG. 1, a description will be given of the vacuum processing
apparatus, based on FIGS. 2 to 4. FIG. 2 is a conceptual block
diagram of the aforementioned embodiment of the vacuum processing
apparatus according to the present invention, and FIG. 3 is a
schematic diagram of this apparatus. The vacuum processing
apparatus shown in these figures, as one embodiment of the present
invention, is a dry etching apparatus that uses gas plasma to etch
the wafer to be processed. In the figures, vacuum processing
apparatus 10 comprises atmospheric loader 1 equipped with a
transport unit for carrying the wafers within cassettes 1a, 1b, and
1c, from a plurality of mutually adjacent cassette tables 2a, 2b,
and 2c, or to cassette tables 2a, 2b, and 2c; vacuum loader 7
equipped with vacuum wafer-processing chambers (etching chambers)
11a and 11b, and with vacuum transport chamber 16 which
communicates with the processing chambers via gate valves 15a and
15b; and locking unit 6 that includes loading lock chamber 6a and
unloading lock chamber 6b, both equipped with a gate valve for
connecting the atmospheric transport unit and vacuum transport
chamber.
[0034] In this embodiment, cassette tables 2a or 2c are arranged in
parallel and they always hold cassettes 1a or 1c in a position from
which they can be loaded/unloaded, more specifically, a fixed
position on an almost horizontal plane, without the original
positions or directions of the cassette tables being disturbed.
Cassette tables 2a and 2b are arranged next to one another in
parallel. Cassette table 2c is located at the rightmost end of
tables 2a and 2b. Both cassettes 1a and 1b are used for
accommodating unprocessed or processed wafers and have a storage
capacity of multiple wafers (usually, 25 pieces). In this case,
cassette 1c is for accommodating the dummy wafers to undergo dry
cleaning with plasma (hereinafter, referred to as plasma cleaning)
or for collecting plasma-cleaned dummy wafers, and has a storage
capacity of multiple wafers (usually, 25 pieces).
[0035] Loading lock chamber 6a and unloading lock chamber 6b that
face cassette tables 2a and 2b, respectively, are arranged inside
atmospheric loader 1, and transport unit 13 is located between
cassette tables 2a/2b and lock chambers 6a/6b. Loading lock chamber
6a has vacuum exhaust unit 3 and gas induction unit 4 and can load
unprocessed wafers into vacuum loader 7 via gate valve 12a.
Unloading lock chamber 6b, likewise, has vacuum exhaust unit 3 and
gas induction unit 4, and can take processed wafers out into
atmospheric loader 1 via gate valve 12b. Transport unit 13 has a
robot equipped with X-, Y-, Z- and theta-axes, and operates to
enable wafers 20 to be exchanged between lock chambers 6a/6b and
cassettes 1a/1b and between lock chambers 6a/6b and cassette
1c.
[0036] Loading lock chamber 6a and unloading lock chamber 6b are
connected to vacuum transport chamber 16 via gate valves 12b and
12c, respectively. In this case, vacuum transport chamber 16 is
circular and etching chambers 11a and 11b for vacuum processing are
provided on both side walls of vacuum transport chamber 16 via gate
valves 15a and 15b. The etching chambers are described below as an
example. Inside vacuum transport chamber 16 there is provided a
transport unit 14 that operates to enable wafers 20 or dummy wafers
30 to be exchanged between loading lock chamber 6a, unloading lock
chamber 6b, and etching chambers 11a and 11b. Vacuum transport
chamber 16 has also a vacuum exhaust unit 17 which is capable of
exhausting vacuum independently.
[0037] In this case, etching chambers 11a and 11b of the UHF-ECR
reactor are symmetrically arranged with the same configuration so
as to enable etching. Etching chamber 11a is described below as an
example. Etching chamber 11a has a samples mount 8a for placing
wafers 20 and is also provided with a discharge chamber so that
discharge portion 7a is formed above samples mount 8a. Etching
chamber 11a has gas induction unit 10a for supplying a processing
gas to discharge portion 7a, and is also provided with vacuum
exhaust unit 9a for reducing the internal pressure of this etching
chamber to the required level. In addition, etching chamber 11a has
a means for generating, in this case, UHF waves and magnetic fields
for converting into plasma the processing gas to be supplied to
discharge portion 7a.
[0038] In this case, the etching chamber contains sensor 18 that
measures plasma light emission intensity. The value that has been
measured by sensor 18 is sent to control unit 19. Control unit 19
compares the measured value with the required value and judges the
time for cleaning the inside of the etching chamber. Control unit
19 also controls vacuum transport units 13 and 14, thus controlling
the transfer of dummy wafers 30 between cassette 1c and etching
chamber 11a or 11b.
[0039] In the vacuum processing apparatus thus configured, first,
cassettes 1a and 1b containing unprocessed wafers are placed on
cassette tables 2a and 2b, respectively, by a line transport robot
that operates in accordance with the information received from a
host control unit, or by the operator, whereas cassette 1c
containing dummy wafers is placed on cassette table 2c. The
processing apparatus conducts wafer processing or plasma cleaning,
pursuant to either self-identification of the production
information assigned to cassette 1a or 1c, the information received
from the host control unit, or the instruction entered by the
operator.
[0040] For example, vacuum transport units 13 and 14 carry wafers
20, in order from bottom to top, from cassette 1a to etching
chambers 11a and 11b, where the wafers then undergo etching. After
etching, wafers 20 are returned to their original positions within
cassette 1a by vacuum transport units 13 and 14. In this case,
without changing the position and direction of each wafer during
the time from the start of operation to the end, the transport
units take out unprocessed wafers and return only processed ones to
the positions where they were stored before being processed. Thus,
application to automatic operation of semiconductor manufacturing
equipment becomes easy and the contamination of wafers with dirt
can be minimized and high production efficiency and high production
yields can be achieved.
[0041] As etching progresses in the etching chamber 11a or 11b,
reaction products stick to and accumulate on the inner wall of the
etching chamber. The reaction products must therefore be removed by
plasma cleaning to restore the inside of the etching chamber to its
original status. The time to conduct plasma cleaning is judged by
control unit 19. In this case, since etching chamber 11a or 11b has
a portion to which plasma light penetrates, the luminous intensity
of the plasma light immediately after it has penetrated is measured
by sensor 18 and when the measured luminous intensity reaches a
required value, control unit 19 judges that the time for plasma
cleaning has been reached. Or, control unit 19 can be activated to
count the number of wafers which have been processed in the etching
chamber, and when the measured luminous intensity reaches the
required value, the time for plasma cleaning can be judged to have
been reached. Actual plasma cleaning can be conducted either during
the processing of the required number of wafers within cassette 1a
or 1b, or before wafer processing control is advanced to the next
cassette following completion of processing of all wafers 20.
[0042] The sequence of plasma cleaning is described hereunder. This
sequence applies when two dummy wafers 30 of all those (in this
case, 25 wafers) stored within cassette 1c are processed in etching
chamber 11a or 11c.
[0043] The first unused or reusable dummy wafer 30 within cassette
1c is picked by transport unit 13. Although any dummy wafer stored
within cassette 1c can be picked at this time, the position numbers
and usage counts of all dummy wafers within the cassette are
already stored into memory to ensure that the wafers are always
taken out in order with the lowest-usage-count wafer first. After
the first wafer has been picked, it is carried into loading lock
chamber 6a located at the opposite side to that of cassette 1a, via
gate valve (isolated valve) 12a by transport unit 13 in the same
way it transports wafer 20 for etching. Loading lock chamber 6a,
after closing gate valve 12a, is vacuum-exhausted down to the
required vacuum pressure by vacuum exhaust unit 3, then gate valve
12b and gate valve (isolated valve) 15a are opened, and dummy wafer
30 is carried from loading lock chamber 6a to etching chamber 11a
via vacuum transport chamber 16 by transport unit 14. Subsequently,
dummy wafer 30 is placed on samples mount 8a. After closing gate
valve 15a, etching chamber 11a with the dummy wafer mounted inside
provides plasma cleaning under the required conditions.
[0044] During this time, loading lock chamber 6a closes gate valves
12a and 12b and is then returned to the original atmospheric
pressure by gas induction unit 4. Next, loading lock chamber 6a
opens gate valve 12a and carries dummy wafer 30 into loading lock
chamber 5a by transport unit 13 in the same way the first dummy
wafer 20 was carried. After closing gate valve 12a, loading lock
chamber 6a is vacuum-exhausted down to the required vacuum pressure
by vacuum exhaust unit 3 again, then gate valve 12b and gate valve
(isolated valve) 15b are opened, and the second dummy wafer 30 is
carried from loading lock chamber 6a to etching chamber 11b via
vacuum transport chamber 16 by transport unit 13. Subsequently,
gate valve 15b is closed and then the dummy wafer is provided with
plasma cleaning.
[0045] After plasma cleaning of etching chamber 11a containing the
first dummy wafer 20 has been completed, gate valves 15a and 12c
are opened. Used dummy wafer 30 is carried out from etching chamber
11a into unloading lock chamber 6b by transport unit 14, and
following this process, gate valve 12c is closed. Subsequently,
unloading lock chamber 6b is returned to the original atmospheric
pressure by gas induction unit 4 and then gate valve 12d is opened.
Used dummy wafer 30 that has been carried out into unloading lock
chamber 6b is taken out into the atmosphere via gate valve 12d by
transport unit 13 and then returned to the original position within
cassette 1c.
[0046] After plasma cleaning of etching chamber 11b, the second
dummy wafer 20 is likewise returned to the original position within
cassette 1c.
[0047] In this manner, used dummy wafers 30 are returned to the
original positions within cassette 1c and this cassette is always
stocked with dummy wafers 30. After all dummy wafers 30 within
cassette 1c have undergone plasma cleaning or have been reused
several times to reach the scheduled usage count, all these dummy
wafers 30 and cassette 1c are replaced together. The replacement
timing of this cassette is controlled by control unit 19 and the
appropriate instruction signal is sent to the host control unit
that controls the line transport robot, or to the operator.
[0048] The above description of plasma cleaning applies to
continuous plasma cleaning of etching chamber 11a or 11b using only
any two of all dummy wafers 30 stored within cassette 1c. Other
processing methods, however, can also be used.
[0049] For example, etching chambers 11a or 11b can likewise be
provided with plasma cleaning sequentially using one dummy wafer
30. In this example of plasma cleaning, unprocessed wafer 20 in an
etching chamber other than that which is to undergo plasma cleaning
can be provided with etching and the apparatus can be cleaned
without the etching process being interrupted.
[0050] In another example of a plasma cleaning method in which an
etching chamber, a post-processing chamber, a film-forming chamber,
and other types of processing chambers are to be used and wafers
are sequentially sent to each such chamber for processing, dummy
wafers 30 can also be sent during sequential processing of wafers
20 stored within cassette 1a or 2a, and these dummy wafers 30 are
merely passed through a processing chamber not requiring plasma
cleaning. In this case, dummy wafers 30 are processed only after
arriving at the processing chambers that require plasma cleaning,
whereby the corresponding processing chambers can be provided with
plasma cleaning as appropriate.
[0051] According to these embodiments, a cassette containing dummy
wafers and a cassette containing the wafers to be processed can be
arranged together in the atmosphere, then only dummy wafers are
loaded from the cassette into the apparatus during the cleaning
process by activating the same transport unit as that used for
carrying the wafers to be processed, and after plasma cleaning,
used dummy wafers can be returned to their original positions
within the cassette. The adoption of this method makes it
unnecessary to provide a special mechanism for plasma cleaning and
thus enables the apparatus to be simplified. Also, plasma cleaning
does not need to be handled as a special processing sequence, and
this cleaning process can be incorporated into normal etching to
perform a series of operations efficiently.
[0052] In addition, since plasma-cleaned dummy wafers are
automatically returned to their original positions within the
cassette placed in the atmosphere, used dummy wafers are not placed
in mixed form with unprocessed or processed wafers in the vacuum
chamber. Unlike conventional apparatuses, therefore, the apparatus
based on the present invention does not cause wafer contamination
with dirt or residual gases.
[0053] Furthermore, since used dummy wafers are not only
automatically returned to their original positions within the
cassette, but also controlled in terms of usage count, it is
possible to avoid confusion between used dummy wafers, unused dummy
wafers, dummy wafers low in usage count, and dummy wafers high in
usage count, and thus to use each dummy wafer efficiently and
without inconvenience during plasma cleaning.
[0054] Furthermore, a plurality of processing chambers are
provided, wafers and their dummies can be carried using the same
transport unit, and the control unit controls the cleaning timing
of each processing chamber to enable timely plasma cleaning. These,
in turn, enable arbitrary cleaning time period setting, dry
cleaning without interruption in the flow of processing, and
efficient processing for improved production efficiency.
[0055] In a configuration as described above, the axial line
passing through the middle of the vacuum transport chamber and the
locking unit is taken as line A; the axial line passing through the
middle of the vacuum transport chamber and that of etching chamber
11a is taken as line B; and the axial line passing through the
middle of the vacuum transport chamber and that of etching chamber
11b is taken as line C.
[0056] Etching chambers 11a and 11b, which are vacuum processing
chambers for processing wafers, are both formed by a UHF-ECR
reactor. Two such chambers are provided only at the opposite side
to that of the locking unit across vacuum transport chamber 16,
symmetrically with respect to axial line A passing through the
middle of vacuum transport chamber 16 and locking unit 6. Also, the
foregoing two etching chambers, 11a and 11b, are arranged at the
acute angle, alpha, formed by lines B and C, and at the opposite
side to that of vacuum transport chamber 16, and atmospheric loader
1, vacuum loader 7, and locking unit 6 are arranged in T-shaped
form.
[0057] As shown in FIG. 4, UHF-ECR antennas 110a and 110b are
parallel to the abovementioned axial line A and are opened at the
opposite side to that of the vacuum transport chamber. The
structure of the antennas is described hereunder.
[0058] Prior to antennas 110a and 110b being opened, magnetic field
generating units 101a and 101b used in etching chambers 11a and
11b, respectively, and antenna power lines 120a and 120b are lifted
off by lifting unit 200. Other components of the antenna sections
are detailed hereunder. Also, see FIG. 8.
[0059] The procedures for disassembling and reassembling the
apparatus based on embodiments of the present invention, and the
methods of removing the components of the apparatus will be
described hereunder with reference to FIGS. 5 to 7.
[0060] FIG. 5 is a perspective view of the main section of the
plasma etching apparatus, with part thereof being shown in cross
section in order to represent the maintenance status based on the
present invention. Above the side wall 102 mounted on vacuum
chamber 105 there is installed an antenna 110, around which a
magnetic field generating unit 101 is installed, and antenna power
line 120 is connected to antenna 110 via lead-in terminal 126.
[0061] For apparatus disassembly during wet cleaning, processing
chamber 100 and vacuum chamber 105 are exposed to the atmosphere,
and lead-in terminal 126 that connects the antenna 110 to the
antenna power line 120 is disconnected.
[0062] The next step is shown in FIG. 6. First, as indicated by
arrow (1) in FIG. 6, magnetic field generating unit 101 and antenna
power line 120 (not shown) are lifted by lifting unit 200 and then
are fixed at a position that facilitates maintenance. Next, as
indicated by arrow (2), antenna 110 is opened by being rotated
about the shaft of hinge 118 until the antenna is disposed in an
almost horizontal position, and then plate 115 and ring 116 are
lifted off as indicated by arrows (3) and (4). In this case, as
shown in FIG. 4, antenna 110 is rotated and held at the operator
side, which is the opposite side to that of vacuum transport
chamber 16.
[0063] The next step is shown in FIG. 7. As indicated by arrows (5)
and (6), side wall inner unit 103 and bottom cover 135 are lifted
off.
[0064] Also, focus ring 132 of the bottom electrode is removed.
Removed components are subjected to processing, such as removal of
film deposits, ultrasonic cleaning, and drying. Subsequently, all
removed components are reinstalled using the reverse procedure to
that described above. Next, the apparatus is restored to the
original status and then undergoes vacuum evacuation.
[0065] Subsequently, the arrival of processing chamber 100 at the
required vacuum pressure is confirmed, and then, as required,
foreign substance checks and rate checks are performed. After
normal operation of the apparatus has been confirmed, it is
restored to the intended operational status and wet cleaning is
completed. With one complete set of available replacement
components at hand, since immediate restoration and vacuum
evacuation of the apparatus is possible, its downtime (Good Wafer
to Good Wafer) can be minimized.
[0066] Furthermore, improvement of wet cleaning efficiency by the
adoption of an appropriate measure, such as using no bolts in the
sealed areas or connections of the vacuum flange section, reduces
apparatus downtime to about three to four hours, thus maximizing
apparatus availability.
[0067] In this embodiment, as shown in FIG. 6, since antenna 110
can be opened by rotating it about the shaft of hinge 118, the
entire antenna does not need to be removed by lifting it from the
processing chamber, nor are any burdens of lifting heavy objects
imposed on maintenance personnel. Also, since antennas 110a and
110b are rotated and held in the same direction, both antennas can
be easily serviced and do not interfere with one another, with the
result that their arrangement is smooth and effective use of their
spaces is possible. As already described, since plate 115 and ring
116 can also be easily removed just by lifting them in the
directions of arrows (3) and (4), the maintenance efficiency can be
improved and the likelihood of components being damaged is
reduced.
[0068] FIG. 8 is a top plan view of a full-flat open-structured
vacuum vessel, as seen when it is mounted in a plasma processing
system according to another embodiment of the present invention.
This system has two plasma processing chambers, E1 and E2, and
wafer samples are carried from loader mechanism 151 through loading
lock chamber 152 to buffer chamber 153, and the samples are then
transferred from sample transport mechanism 154 to plasma
processing chambers E1 and E2.
[0069] In FIG. 8, the status of plasma processing chamber E1, as it
appears when system assembly is completed, is shown, and magnetic
field generating unit 101 and antenna power line 120 are mounted
above vacuum chamber 105. Likewise, plasma processing chamber E2
during wet cleaning is shown, in which case, the inside of
processing chamber 100 is exposed to the atmosphere and antenna 110
is opened by hinge 118 to take a fully flat state. Magnetic field
generating unit 101 and antenna power line 120 are moved away to a
position that facilitates maintenance. Maintenance personnel M
present in the maintenance area can easily perform maintenance
operations because antenna 110 is opened in the direction of the
maintenance personnel M (namely, outward with respect to base frame
150 of the system) and is about half protruded with respect to base
frame 150. This antenna is not projected too far, nor does it
occupy a superfluous space in the maintenance area. It becomes
possible, by mounting a plasma processing chamber (reactor) of
full-flat open structure in this way, to implement a plasma
processing system well balanced between total configurational
compactness and maintainability.
[0070] Although, in FIG. 8, magnetic field generating unit 101 is
as shown protruding from the system area, this unit actually does
not protrude outward after it has been moved away in the upward
direction of plasma processing chamber E2.
[0071] Referring again to FIG. 1, in the foregoing configuration,
two etching chambers are provided only at the opposite side to that
of the locking unit across the vacuum transport chamber,
symmetrically with respect to the axial line passing through the
middle of the vacuum transport chamber and the locking unit, and
the foregoing two vacuum processing chambers are arranged at an
acute angle, at the opposite side to that of the vacuum transport
chamber, and in linear form along line D in all vacuum chambers of
the vacuum processing apparatus. Line D is parallel to line E that
connects the centers of the vacuum transport chambers. Under such
arrangement of the vacuum processing apparatus components, since
the antennas are opened in a vertical direction relative to lines D
and E, even when the adjacent vacuum processing chambers of the
vacuum processing apparatus are exposed to the atmosphere at the
same time, a sufficient maintenance space is ensured, compared with
the case in which the antennas are opened in the direction from the
vacuum transport chamber toward the vacuum processing chambers.
[0072] According to the present invention, it is possible to
minimize increases in manufacturing costs, while at the same time
providing flexibility to increases in sample size, and to provide a
vacuum processing apparatus that has excellent maintainability.
Also, incorporation of such vacuum processing apparatus into
semiconductor manufacturing equipment makes it possible to ensure
the complement of vacuum processing apparatus and minimize
manufacturing costs while at the same time providing flexibility to
increases in sample size, and to supply semiconductor manufacturing
equipment whose maintainability does not deteriorate.
[0073] Furthermore, according to the present invention, one portion
of the vacuum vessel constituting the processing chambers can be
constructed as a section that can be opened and closed, and when
this section directs the processing chambers upward, components can
be maintained in their physically stable status at the operator
side in an almost horizontal position by friction or by a securing
section. Accordingly, since the top of the processing chambers
opens in the direction of the maintenance area, maintenance
personnel can easily both access the processing chambers and
perform maintenance operations from the top. As a result, the
maintenance personnel can easily handle components during
maintenance and maintainability is improved, which in turn enables
the realization of a plasma processing apparatus which has
excellent maintainability, is easy to use and contributes to an
improvement in productivity.
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