U.S. patent application number 16/092683 was filed with the patent office on 2019-05-23 for substrate processing method and substrate processing device.
The applicant listed for this patent is TOKYO ELECTRON LIMITED. Invention is credited to Tetsuro TAKAHASHI, Satoshi TODA.
Application Number | 20190153599 16/092683 |
Document ID | / |
Family ID | 60042590 |
Filed Date | 2019-05-23 |
United States Patent
Application |
20190153599 |
Kind Code |
A1 |
TODA; Satoshi ; et
al. |
May 23, 2019 |
SUBSTRATE PROCESSING METHOD AND SUBSTRATE PROCESSING DEVICE
Abstract
A predetermined process is performed on two target substrates
using a substrate processing device that includes two processing
parts for performing a substrate process on each of the two target
substrates, a gas supply mechanism for separately supplying gases
to the two processing parts, and a common exhaust mechanism for
collectively exhausting the gases inside the two processing parts.
A first mode is executed in which an HF gas and an NH.sub.3 gas are
supplied to one of the two processing parts, and the HF gas is not
supplied to the other of the two processing parts. Subsequently, a
second mode is executed in which the HF gas and the NH.sub.3 gas
are supplied to the two processing parts under the same gas
conditions. In the first mode, a pressure difference is prevented
from occurring between the two processing parts.
Inventors: |
TODA; Satoshi;
(Nirasaki-shi, Yamanashi, JP) ; TAKAHASHI; Tetsuro;
(Nirasaki-shi, Yamanashi, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
TOKYO ELECTRON LIMITED |
Minato-ku, Tokyo |
|
JP |
|
|
Family ID: |
60042590 |
Appl. No.: |
16/092683 |
Filed: |
March 3, 2017 |
PCT Filed: |
March 3, 2017 |
PCT NO: |
PCT/JP2017/008590 |
371 Date: |
October 10, 2018 |
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C23C 16/52 20130101;
H01L 21/306 20130101; H01L 21/31111 20130101; C23C 16/45502
20130101; C23C 16/455 20130101; C23C 16/4412 20130101 |
International
Class: |
C23C 16/455 20060101
C23C016/455; H01L 21/306 20060101 H01L021/306; C23C 16/52 20060101
C23C016/52; C23C 16/44 20060101 C23C016/44 |
Foreign Application Data
Date |
Code |
Application Number |
Apr 15, 2016 |
JP |
2016-081682 |
Claims
1. A substrate processing method for performing a predetermined
process on a plurality of target substrates under a vacuum
atmosphere using a substrate processing device that includes a
plurality of processing parts for performing a substrate process on
each of the plurality of target substrates, a gas supply mechanism
for separately supplying gases to the plurality of processing
parts, and a common exhaust mechanism for exhausting the gases
inside the plurality of processing parts in a collective manner,
the method comprising: performing a first mode in which a first gas
is supplied to a portion of the plurality of processing parts and a
second gas different from the first gas is supplied to another
portion of the plurality of processing parts, while controlling the
common exhaust mechanism so as to exhaust a processing gas in
common from the plurality of processing parts; and subsequently,
performing a second mode in which the first gas as the processing
gas is supplied to all of the plurality of processing parts under
the same gas conditions, while exhausting the processing gas from
the plurality of processing parts in a collective manner by the
common exhaust mechanism, wherein, in the first mode, a pressure
difference is prevented from occurring between the plurality of
processing parts.
2. The substrate processing method of claim 1, wherein the
performing a first mode includes controlling an amount of the
second gas supplied to the another portion of the plurality of
processing parts so as to prevent the pressure difference from
occurring between the portion of the plurality of processing parts
and the another portion of the plurality of processing parts.
3. The substrate processing method of claim 1, wherein the second
gas is at least one of an inert gas and a non-reactive gas that is
not reactive with the plurality of target substrates.
4. The substrate processing method of claim 3, wherein the
performing a first mode includes: performing, in the portion of the
plurality of processing parts, the substrate process using the
first gas which is the processing gas for the plurality of target
substrates; and bypassing, in the another portion of the plurality
of processing parts, the substrate process by supplying the second
gas as a supplement gas instead of supplying the first gas which is
the processing gas for the plurality of target substrates.
5. The substrate processing method of claim 4, further comprising:
prior to the performing the first mode, stabilizing pressures of
the plurality of processing parts by regulating the pressures of
the plurality of processing parts with a pressure regulating gas,
wherein the stabilizing pressures includes setting a flow rate of
the pressure regulating gas to a level at which the first gas used
as the processing gas and the second gas used as the supplement gas
are suppressed from backwardly diffusing between the plurality of
processing parts, and a flow of the pressure regulating gas toward
the common exhaust mechanism is formed, in the first mode of the
substrate process.
6. The substrate processing method of claim 5, wherein a portion of
the gases supplied during the substrate process, which is not used
for the substrate process, is used as the pressure regulating gas,
and the flow rate of the pressure regulating gas in the stabilizing
pressures is set to be larger than a flow rate of the pressure
regulating gas used in the substrate process.
7. The substrate processing method of claim 6, wherein the flow
rate of the pressure regulating gas in the stabilizing pressures is
set to be three times or more the flow rate of the pressure
regulating gas used in the substrate process.
8. The substrate processing method of claim 4, wherein a dilution
gas for diluting the first gas is used as the second gas.
9. (canceled)
10. (canceled)
11. (canceled)
12. (canceled)
13. (canceled)
14. A substrate processing device for performing a predetermined
process on a plurality of target substrates under a vacuum
atmosphere, comprising: a plurality of processing parts, each of
which configured to perform a substrate process on each of the
plurality of target substrates; a gas supply mechanism configured
to separately supply processing gases to the plurality of
processing parts; a common exhaust mechanism configured to exhaust
the processing gases inside the plurality of processing parts in a
collective manner; and a controller configured to control the gas
supply mechanism and the common exhaust mechanism to execute the
substrate process on the plurality of target substrates in a
sequence of first and second modes, wherein the first mode involves
supplying a first gas to a portion of the plurality of processing
parts and supplying a second gas different from the first gas to
another portion of the plurality of processing parts, while
controlling the common exhaust mechanism so as to exhaust the
processing gas in common from the plurality of processing parts,
and the second mode involves supplying the first gas as the
processing gases to all of the plurality of processing parts under
the same gas conditions, while exhausting the processing gases from
the plurality of processing parts in a collective manner by the
common exhaust mechanism, wherein, in the first mode, the
controller controls such that a pressure difference is prevented
from occurring between the plurality of processing parts.
15. The substrate processing device of claim 14, wherein the
controller controls, in the first mode, an amount of the second gas
supplied to the another portion of the plurality of processing
parts so as to prevent the pressure difference from occurring
between the portion of the plurality of processing parts and the
another portion of the plurality of processing parts.
16. The substrate processing device of claim 14, wherein the second
gas is at least one of an inert gas and a non-reactive gas that is
not reactive with the plurality of target substrates.
17. The substrate processing device of claim 16, wherein the
controller controls in the first mode such that the substrate
process is performed using the first gas which is the processing
gases for the plurality of target substrates in the portion of the
plurality of processing parts, and the substrate process is not
performed by supplying the second gas as a supplement gas to the
another portion of the plurality of processing parts, instead of
supplying the first gas which is the processing gases for the
plurality of target substrates.
18. The substrate processing device of claim 17, wherein the
controller controls such that, prior to the first mode of the
substrate process, pressures of the plurality of processing parts
are stabilized by regulating the pressures of the plurality of
processing parts with a pressure regulating gas, wherein in the
stabilization, a flow rate of the pressure regulating gas is
controlled to be set to a level at which the first gas used as the
processing gas and the second gas used as the supplement gas are
suppressed from backwardly diffusing between the plurality of
processing parts, and a flow of the pressure regulating gas toward
the common exhaust mechanism is formed, in the first mode of the
substrate process.
19. The substrate processing device of claim 18, wherein a portion
of the gases supplied during the substrate process, which is not
used for the substrate process, is used as the pressure regulating
gas, wherein the controller controls such that the flow rate of the
pressure regulating gas in the stabilization is set to be larger
than a flow rate of the pressure regulating gas used in the
substrate process.
20. The substrate processing device of claim 19, wherein the
controller controls such that the flow rate of the pressure
regulating gas in the stabilization is set to be three times or
more the flow rate of the pressure regulating gas used in the
substrate process.
21. The substrate processing device of claim 17, wherein a dilution
gas for diluting the first gas is used as the second gas.
22. (canceled)
23. (canceled)
24. (canceled)
25. (canceled)
26. (canceled)
27. A storage medium storing a program that operates on a computer
and controls a substrate processing device that includes a
plurality of processing parts for performing a substrate process on
each of a plurality of target substrates, a gas supply mechanism
for separately supplying gases to the plurality of processing
parts, and a common exhaust mechanism for exhausting the gases
inside the plurality of processing parts in a collective manner,
wherein the program, when executed, causes the computer to control
the substrate processing device so as to perform a substrate
processing method, the method comprising: performing a first mode
in which a first gas is supplied to a portion of the plurality of
processing parts and a second gas different from the first gas is
supplied to another portion of the plurality of processing parts,
while controlling the common exhaust mechanism so as to exhaust a
processing gas in common from the plurality of processing parts;
and subsequently, performing a second mode in which the first gas
as the processing gas is supplied to all of the plurality of
processing parts under the same gas conditions, while exhausting
the processing gas from the plurality of processing parts in a
collective manner by the common exhaust mechanism, wherein, in the
first mode, a pressure difference is prevented from occurring
between the plurality of processing parts.
Description
TECHNICAL FIELD
[0001] The present disclosure relates to a substrate processing
method and a substrate processing device for processing a process
on a target substrate.
BACKGROUND
[0002] Semiconductor devices are manufactured by repeatedly
performing various processes such as an etching process, a
film-forming process and the like, on a semiconductor wafer
(hereinafter simply referred to as a wafer) which is a target
substrate.
[0003] As an apparatus for performing such a substrate process, a
single wafer type processing apparatus for processing target
substrates one by one has been conventionally widely used. However,
such a processing apparatus is required to increase throughput, and
a processing apparatus for performing the substrate process on two
or more target substrates at a time while maintaining the platform
of the single wafer type processing apparatus has also been used
(see, e.g., Patent Document 1).
[0004] In the substrate processing device disclosed in Patent
Document 1, a substrate mounting table on which a plurality of
target substrates is mounted is installed inside a chamber. A
plurality of process regions and a plurality of separation regions
that separates the plurality of process regions from each other are
alternately defined above the substrate mounting table along a
circumferential direction of the substrate mounting table. In the
substrate process, the substrate mounting table is rotated such
that the plurality of target substrates pass through the regions in
the order of "process region separation region process region
separation region, . . . ". In this way, the plurality of target
substrates is processed under different gas conditions.
PRIOR ART DOCUMENTS
Patent Documents
[0005] Patent Document 1: Japanese laid-open publication No.
2010-080924
[0006] In the substrate processing device disclosed in Patent
Document 1, in order to process the plurality of target substrates
under the different gas conditions, exhaust mechanisms are
separately installed for the process regions independently of each
other. This increases the manufacturing costs of the substrate
processing device.
SUMMARY
[0007] The present disclosure provides some embodiments of a
substrate processing method and a substrate processing device,
which are capable of performing a substrate process on a plurality
of target substrates under different gas conditions with high
precision using a common exhaust mechanism, when processing the
plurality of target substrates by a plurality of processing
parts.
[0008] According to a first aspect of the present disclosure, there
is provided a substrate processing method for performing a
predetermined process on a plurality of target substrates under a
vacuum atmosphere using a substrate processing device that includes
a plurality of processing parts for performing a substrate process
on each of the plurality of target substrates, a gas supply
mechanism for separately supplying gases to the plurality of
processing parts, and a common exhaust mechanism for exhausting the
gases inside the plurality of processing parts in a collective
manner. The method includes: performing a first mode in which a
first gas is supplied to a portion of the plurality of processing
parts and a second gas different from the first gas is supplied to
another portion of the plurality of processing parts, while
controlling the common exhaust mechanism so as to exhaust a
processing gas in common from the plurality of processing parts;
and subsequently, performing a second mode in which the first gas
as the processing gas is supplied to all of the plurality of
processing parts under the same gas conditions, while exhausting
the processing gas from the plurality of processing parts in a
collective manner by the common exhaust mechanism, wherein, in the
first mode, a pressure difference is prevented from occurring
between the plurality of processing parts.
[0009] In the first aspect, when performing the first mode, an
amount of the second gas supplied to the another portion of the
plurality of processing parts may be controlled so as to prevent
the pressure difference from occurring between the portion of the
plurality of processing parts and the another portion of the
plurality of processing parts.
[0010] At least one of an inert gas and a non-reactive gas that is
not reactive with the plurality of target substrates may be used as
the second gas. Further, when performing the first mode, in the
portion of the plurality of processing parts, the substrate process
using the first gas which is the processing gas for the plurality
of target substrates may be performed; and in the another portion
of the plurality of processing parts, the substrate process may not
be performed by supplying the second gas as a supplement gas
instead of supplying the first gas which is the processing gas for
the plurality of target substrates.
[0011] In this case, the method may further include, prior to the
performing the first mode, stabilizing pressures of the plurality
of processing parts by regulating the pressures of the plurality of
processing parts with a pressure regulating gas. When stabilizing
the pressures, a flow rate of the pressure regulating gas may be
set to a level at which the first gas used as the processing gas
and the second gas used as the supplement gas are suppressed from
backwardly diffusing between the plurality of processing parts, and
a flow of the pressure regulating gas toward the common exhaust
mechanism is formed, in the first mode of the substrate process. A
portion of the gases supplied during the substrate process, which
is not used for the substrate process, may be used as the pressure
regulating gas, and the flow rate of the pressure regulating gas in
the stabilizing pressures may be set to be larger than a flow rate
of the pressure regulating gas used in the substrate process. The
flow rate of the pressure regulating gas in the stabilizing
pressures may be set to be three times or more the flow rate of the
pressure regulating gas used in the substrate process.
[0012] In some embodiments, a dilution gas for diluting the first
gas may be used as the second gas.
[0013] According to a second aspect of the present disclosure,
there is provided a substrate processing method for performing a
predetermined process on a plurality of target substrates under a
vacuum atmosphere using a substrate processing device that includes
a plurality of processing parts for performing a substrate process
on each of the plurality of target substrates, a gas supply
mechanism for separately supplying gases to the plurality of
processing parts, and a common exhaust mechanism for exhausting the
gases inside the plurality of processing parts in a collective
manner. The method includes: performing a first mode in which an HF
gas and an NH.sub.3 gas as processing gases are supplied to a
portion of the plurality of processing parts so as to perform an
etching process, and instead of the HF gas, at least one of an
inert gas and a non-reactive gas which is not reactive with the
plurality of target substrates is supplied to another portion of
the plurality of processing parts so as not to perform the etching
process, while controlling the common exhaust mechanism so as to
exhaust the processing gases in common from the plurality of
processing parts; and subsequently, performing a second mode in
which the HF gas and the NH.sub.3 gas as the processing gases are
supplied to all of the plurality of processing parts so as to
perform the etching process, while exhausting the processing gases
in common from the plurality of processing parts in a collective
manner by the common exhaust mechanism, wherein, in the first mode,
the supply of the gases is performed to prevent a pressure
difference from occurring between the plurality of processing
parts.
[0014] In the second aspect, when performing the first mode, the HF
gas and the NH.sub.3 gas as the processing gases and the inert gas
may be supplied to the portion of the plurality of processing
parts, and supplying the inert gas or the inert gas and the
NH.sub.3 gas to the another portion of the plurality of processing
parts. The inert gas may be used as a supplement gas for regulating
pressures of the portion of the plurality of processing parts and
the another portion of the plurality of processing parts.
[0015] In some embodiments, the method may further include, prior
to the performing a first mode, stabilizing pressures of the
plurality of processing parts by regulating the pressures of the
plurality of processing parts with the inert gas or the inert gas
and the NH.sub.3 gas as pressure regulating gases. When stabilizing
the pressures, flow rates of the pressure regulating gases may be
set to a level at which the processing gases and the inert gas are
suppressed from backwardly diffusing between the plurality of
processing parts, and a flow of the pressure regulating gases
toward the common exhaust mechanism is formed, in the first mode of
the substrate process. The flow rates of the pressure regulating
gases in the stabilizing pressures may be set to be larger than
flow rates of the pressure regulating gases used in the substrate
process. The flow rates of the pressure regulating gases in the
stabilizing pressures may be set to be three times or more the flow
rates of the pressure regulating gases used in the substrate
process.
[0016] According to a third aspect of the present disclosure, there
is provided a substrate processing device for performing a
predetermined process on a plurality of target substrates under a
vacuum atmosphere, including: a plurality of processing parts, each
of which configured to perform a substrate process on each of the
plurality of target substrates; a gas supply mechanism configured
to separately supply processing gases to the plurality of
processing parts; a common exhaust mechanism configured to exhaust
the processing gases inside the plurality of processing parts in a
collective manner; and a controller configured to control the gas
supply mechanism and the common exhaust mechanism to execute the
substrate process on the plurality of target substrates in a
sequence of first and second modes, wherein the first mode involves
supplying a first gas to a portion of the plurality of processing
parts and supplying a second gas different from the first gas to
another portion of the plurality of processing parts, while
controlling the common exhaust mechanism so as to exhaust the
processing gas in common from the plurality of processing parts,
and the second mode involves supplying the first gas as the
processing gases to all of the plurality of processing parts under
the same gas conditions, while exhausting the processing gases from
the plurality of processing parts in a collective manner by the
common exhaust mechanism, wherein, in the first mode, the
controller controls such that a pressure difference is prevented
from occurring between the plurality of processing parts.
[0017] According to a fourth aspect of the present disclosure,
there is provided a substrate processing device for performing a
predetermined process on a plurality of target substrates under a
vacuum atmosphere, including: a plurality of processing parts, each
of which configured to perform a substrate process on each of the
plurality of target substrates; a gas supply mechanism configured
to separately supply processing gases to the plurality of
processing parts; a common exhaust mechanism configured to exhaust
the processing gases inside the plurality of processing parts in a
collective manner; and a controller configured to control the gas
supply mechanism and the common exhaust mechanism to execute the
substrate process on the plurality of target substrates in a
sequence of first and second modes, wherein the first mode involves
supplying an HF gas and an NH.sub.3 gas as the processing gases to
a portion of the plurality of processing parts so as to perform an
etching process, and instead of the HF gas, supplying at least one
of an inert gas and a non-reactive gas which is not reactive with
the plurality of target substrates to another portion of the
plurality of processing parts so as not to perform the etching
process, while controlling the common exhaust mechanism so as to
exhaust the processing gases in common from the plurality of
processing parts; and the second mode involves supplying the HF gas
and the NH.sub.3 gas as the processing gases to all of the
plurality of processing parts so as to perform the etching process,
while exhausting the processing gases from the plurality of
processing parts in a collective manner by the common exhaust
mechanism, wherein the controller controls in the first mode such
that the supply of the gases is performed to prevent a pressure
difference from occurring between the plurality of processing
parts.
[0018] According to a fifth aspect of the present disclosure, there
is provided a storage medium storing a program that operates on a
computer and controls a substrate processing device that includes a
plurality of processing parts for performing a substrate process on
each of a plurality of target substrates, a gas supply mechanism
for separately supplying gases to the plurality of processing
parts, and a common exhaust mechanism for exhausting the gases
inside the plurality of processing parts in a collective manner,
wherein the program, when executed, causes the computer to control
the substrate processing device so as to perform a substrate
processing method. The method includes: performing a first mode in
which a first gas is supplied to a portion of the plurality of
processing parts and a second gas different from the first gas is
supplied to another portion of the plurality of processing parts,
while controlling the common exhaust mechanism so as to exhaust a
processing gas in common from the plurality of processing parts;
and subsequently, performing a second mode in which the first gas
as the processing gas is supplied to all of the plurality of
processing parts under the same gas conditions, while exhausting
the processing gas from the plurality of processing parts in a
collective manner by the common exhaust mechanism, wherein, in the
first mode, a pressure difference is prevented from occurring
between the plurality of processing parts.
[0019] According to the present disclosure, it is possible to
perform a substrate process on a plurality of target substrates
under different gas conditions with high precision using a common
exhaust mechanism, when processing the plurality of target
substrates by a plurality of processing parts.
BRIEF DESCRIPTION OF DRAWINGS
[0020] FIG. 1 is a sectional view illustrating an example of a
substrate processing device according to an embodiment of the
present disclosure.
[0021] FIG. 2 is a system configuration view illustrating a
configuration example of a gas supply mechanism.
[0022] FIG. 3A is a sectional view for explaining a substrate
processing operation in a common substrate processing mode by a COR
processing apparatus according to an embodiment of the present
disclosure.
[0023] FIG. 3B is a sectional view for explaining a substrate
processing operation in an independent substrate processing mode by
the COR processing apparatus according to the embodiment of the
present disclosure.
[0024] FIG. 4 is a view schematically illustrating a substrate
processing mode according to a reference example.
[0025] FIG. 5 is a flow chart illustrating an example of a process
sequence in the substrate processing device of FIG. 1.
[0026] FIG. 6 is a timing chart illustrating a specific gas flow
when implementing an example of a sequence in the substrate
processing device of FIG. 1.
[0027] FIG. 7 is a timing chart illustrating a specific gas flow
when implementing another example of the sequence in the substrate
processing device of FIG. 1.
[0028] FIG. 8 is a view for explaining the effect of the sequence
of FIG. 7.
[0029] FIG. 9 is a view schematically illustrating an example of a
chamber configuration of a substrate processing device.
[0030] FIG. 10 is a view schematically illustrating another example
of the chamber configuration of the substrate processing
device.
DETAILED DESCRIPTION
[0031] Embodiments of the present disclosure will now be described
in detail with reference to the accompanying drawings.
<Substrate Processing Device>
[0032] FIG. 1 is a sectional view illustrating an example of a
substrate processing device according to an embodiment of the
present disclosure. In this example, a COR processing apparatus
which performs a chemical oxide removal (COR) process (etching
process) will be described as the substrate processing device.
[0033] A typical example of the COR process is a substrate process
of supplying a gas including an HF gas and a gas including an
NH.sub.3 gas onto an oxide film existing on a surface of a
substrate such as a silicon wafer inside a chamber, thus removing
the oxide film from the surface of the silicon wafer.
[0034] As illustrated in FIG. 1, a COR processing apparatus 100
includes a hermetically sealed chamber 10. The chamber 10 is made
of, for example, aluminum or an aluminum alloy, and includes a
chamber main body 51 and a lid 52. The chamber main body 51
includes a lateral wall portion 51a and a bottom portion 51b. An
upper portion of the chamber main body 51 is opened and closed by
the lid 52. The lateral wall portion 51a and the lid 52 are sealed
by a seal member 51c to secure the airtightness of the chamber
10.
[0035] Two processing parts 11a and 11b for performing a substrate
process on a plurality of target substrates are installed inside
the chamber 10. The two processing parts 11a and 11b include
substrate mounting tables 61a and 61b, respectively. Wafers Wa and
Wb as target substrates are mounted on the respective substrate
mounting tables 61a and 61b in a horizontal posture. Gas
introduction members 12a and 12b for introducing a processing gas
into the chamber 10 are installed above the substrate mounting
tables 61a and 61b, respectively. The gas introduction members 12a
and 12b are installed inward of the lid 52. The gas introduction
member 12a and the substrate placing table 61a face each other, and
the gas introduction member 12b and the substrate placing table 61b
face each other. A cylindrical inner wall 71a is installed so as to
surround the gas introduction member 12a and the substrate mounting
table 61a, and a cylindrical inner wall 71b is installed so as to
surround the gas introduction member 12b and the substrate mounting
table 61b. The inner walls 71a and 71b are installed to extend from
the inner side of an upper wall of the lid 52 to the bottom portion
51b of the chamber main body 51. Upper portions of the inner walls
71a and 71b constitute lateral walls of the gas introduction
members 12a and 12b, respectively. A space between the gas
introduction member 12a and the substrate mounting table 61a and a
space between the gas introduction member 12b and the substrate
mounting table 61b are substantially sealed by the inner walls 71a
and 71b, respectively. These spaces constitute process spaces S in
which the wafers Wa and Wb are subjected to the substrate process,
respectively.
[0036] A gas supply mechanism 14 for supplying a gas to each of the
gas introduction members 12a and 12b, an exhaust mechanism 15 for
exhausting the interior of the chamber 10, and a control part 16
for controlling the COR processing apparatus 100 are installed
outside the chamber 10. A loading/unloading port (not shown)
through which the wafer W is loaded into and unloaded is formed in
the lateral wall portion 51a of the chamber main body 51. The
loading/unloading port can be opened and closed by a gate valve
(not shown). A loading/unloading port (not shown) is also formed in
each of the inner walls 71a and 72b and can be opened and closed by
a shutter (not shown).
[0037] Each of the processing parts 1a and 11b has substantially a
circular shape. Each of the substrate mounting tables 61a and 61b
is supported by a base block 62. The base block 62 is fixed to the
bottom portion 51b of the chamber main body 51. A temperature
regulator 63 for regulating a temperature of the wafer W is
installed inside each of the substrate mounting tables 61a and 61b.
The temperature regulator 63 is provided with a pipeline through
which, for example, a temperature regulating medium (for example,
water) circulates. By heat exchange with the temperature regulating
medium flowing in the pipeline, the temperature of the wafer W is
controlled. In addition, a plurality of lifting pins (not shown)
used to transfer the wafer W are installed in the substrate
mounting tables 61a and 61b so as to be moved upward and downward
on a wafer mounting surface.
[0038] The gas supply mechanism 14 supplies a processing gas, such
as an HF gas or an NH.sub.3 gas, and an inert gas (dilution gas),
such as an Ar gas or a N.sub.2 gas, to the processing parts 11a and
11b via the gas introduction members 12a and 12b, respectively. The
gas supply mechanism 14 includes gas supply sources, supply pipes,
valves, flow rate controllers represented by mass flow controllers
and so on, which correspond to the respective gases.
[0039] FIG. 2 is a system configuration view illustrating an
example of a system configuration of the gas supply mechanism 14.
As illustrated in FIG. 2, the gas supply mechanism 14 includes an
Ar gas supply source 141, an HF gas supply source 142, an N.sub.2
gas supply source 143 and an NH.sub.3 gas supply source 144 as the
gas supply sources.
[0040] In this example, the HF gas supplied from the HF gas supply
source 142 is diluted with an Ar gas supplied from the Ar gas
supply source 141 and then supplied to the gas introduction members
12a and 12b. Likewise, the NH.sub.3 gas supplied from the NH.sub.3
gas supply source 144 is also diluted with the N.sub.2 gas supplied
from the N.sub.2 gas supply source 143 and then supplied to the gas
introduction members 12a and 12b.
[0041] An HF gas supply pipe 145 through which the HF gas flows is
branched into two HF gas supply pipes 145a and 145b which are
respectively connected to a supply pipe 146a connected to the gas
introduction member 12a and a supply pipe 146b connected to the gas
introduction member 12b. An Ar gas supply pipe 147 through which
the Ar gas flows is branched into two Ar gas supply pipes 147a and
147b which are respectively connected to the HF gas supply pipes
145a and 145b. Thus, the HF gas can be diluted with the Ar gas.
[0042] Similarly, an NH.sub.3 gas supply pipe 148 through which the
NH.sub.3 gas flows is branched into two NH.sub.3 gas supply pipes
148a and 148b which are respectively connected to the supply pipes
146a and 146b. A N.sub.2 gas supply pipe 149 through which the
N.sub.2 gas flows is branched into two N.sub.2 gas supply pipes
149a and 149b which are respectively connected to the NH.sub.3 gas
supply pipes 148a and 148b. Thus, the NH.sub.3 gas can be diluted
with the N.sub.2 gas.
[0043] In addition to being used as dilution gases, the Ar gas and
the N.sub.2 gas are also used as a purge gas or as a supplement gas
for pressure regulation to be described later.
[0044] Mass flow controllers (MFCs) 150a to 150h and
opening/closing valves 151a to 151h for opening/closing the
respective supply pipes are respectively installed in the HF gas
supply pipes 145a and 145b, the Ar gas supply pipes 147a and 147b,
the NH.sub.3 gas supply pipes 148a and 148b, and the N.sub.2 gas
supply pipes 149a and 149b. The MFCs 150a to 150h and the
opening/closing valves 151a to 151h can be controlled by the
control part 16 independently of each other.
[0045] For example, in the case of performing the normal COR
process in the two processing parts 11a and 11b, both the HF gas
and the NH.sub.3 gas are supplied to each of the gas introduction
members 12a and 12b. In this case, the control part 16 controls all
the opening/closing valves to be opened, as shown in the following
"Case a".
TABLE-US-00001 [Case a] Supply system to gas introduction member
12a Opening/closing valve 151a (Ar) Opened Opening/closing valve
151c (HF) Opened Opening/closing valve 151e (N.sub.2) Opened
Opening/closing valve 151g (NH.sub.3) Opened Supply system to gas
introduction member 12b Opening/closing valve 151b (Ar) Opened
Opening/closing valve 151d (HF) Opened Opening/closing valve 151f
(N.sub.2) Opened Opening/closing valve 151h (NH.sub.3) Opened
[0046] On the other hand, the opening/closing valves may be
controlled such that conditions of gases to be supplied to the
processing parts 11a and 11b via the gas introduction members 12a
and 12b are different from each other. For example, the
opening/closing valves may be controlled as shown in the following
"Case b" and "Case c".
TABLE-US-00002 [Case b] Supply system to gas introduction member
12a Opening/closing valve 151a (Ar) Opened Opening/closing valve
151c (HF) Opened Opening/closing valve 151e (N.sub.2) Opened
Opening/closing valve 151g (NH.sub.3) Opened Supply system to gas
introduction member 12b Opening/closing valve 151b (Ar) Opened
Opening/closing valve 151d (HF) Closed Opening/closing valve 151f
(N.sub.2) Opened Opening/closing valve 151h (NH.sub.3) Closed
TABLE-US-00003 [Case c] Supply system to gas introduction member
12a Opening/closing valve 151a (Ar) Opened Opening/closing valve
151c (HF) Closed Opening/closing valve 151e (N.sub.2) Opened
Opening/closing valve 151g (NH.sub.3) Closed Supply system to gas
introduction member 12b Opening/closing valve 151b (Ar) Opened
Opening/closing valve 151d (HF) Opened Opening/closing valve 151f
(N.sub.2) Opened Opening/closing valve 151h (NH.sub.3) Opened
[0047] That is to say, in Case b, from the state of Case a, the
opening/closing valve 151d and the opening/closing valve 151h are
closed to stop the supply of the HF gas and the NH.sub.3 gas as
processing gases and supply only the Ar gas and the N.sub.2 gas to
the gas introduction member 12b, and the HF gas and the NH.sub.3
gas as the processing gases continue to be supplied to the gas
introduction member 12a. Conversely, in Case c, the supply of the
HF gas and the NH.sub.3 gas to the gas introduction member 12a is
stopped, and the HF gas and the NH.sub.3 gas as the processing
gases continue to be supplied to the gas introduction member
12b.
[0048] For this reason, in Case b, the HF gas and the NH.sub.3 gas
are supplied from the gas introduction member 12a to the processing
part 11a, together with the Ar gas and the N.sub.2 gas which are
inert gases, respectively, while only the Ar gas and the N.sub.2
gas which are inert gases are supplied from the gas introduction
member 12b to the processing part 11b. Conversely, in Case c, the
HF gas and the NH.sub.3 gas are supplied from the gas introduction
member 12b to the processing part 11b, together with the Ar gas and
the N.sub.2 gas which are inert gases, respectively, while only the
Ar gas and the N.sub.2 gas which are inert gases are supplied from
the gas introduction member 12a to the processing part 11a. In this
manner, during processing, it is possible to simultaneously supply
the gases to the processing part 11a and the processing part 11b
under different gas supply conditions. Substrate processing modes
by the control of the valves will be described in detail later.
[0049] The gas introduction members 12a and 12b are provided to
introduce the gases from the gas supply mechanism 14 into the
chamber 10 and supply the gases to the processing parts 11a and
11b. Each of the gas introduction members 12a and 12b has a gas
diffusion space 64 defined therein and has a cylindrical shape. Gas
introduction holes 65 penetrating the upper wall of the chamber 10
are respectively formed in the upper surfaces of the gas
introduction members 12a and 12b. A large number of gas discharge
holes 66 connected to each of the gas diffusion spaces 64 are
respectively formed in the bottom surfaces of the gas introduction
members 12a and 12b. Gases such as the HF gas and the NH.sub.3 gas
supplied from the gas supply mechanism 14 reach the gas diffusion
spaces 64 via the gas introduction holes 65, diffuse inside the gas
diffusion spaces 64, and are uniformly discharged from the gas
discharge holes 66 in the form of a shower. That is to say, each of
the gas introduction members 12a and 12b functions as a gas
dispersion head (shower head) that dispersedly discharges a gas.
The gas introduction members 12a and 12b may be of a post-mix type
in which the HF gas and the NH.sub.3 gas are discharged into the
chamber 10 through different flow paths.
[0050] The exhaust mechanism 15 includes an exhaust pipe 101
connected to an exhaust port (not shown) formed in the bottom
portion 51b of the chamber 10. Further, the exhaust mechanism 15
includes an automatic pressure control valve (APC) 102 for
controlling an internal pressure of the chamber 10 and a vacuum
pump 103 for exhausting the interior of the chamber 10, which are
installed in the exhaust pipe 101. The exhaust port is formed
outside the inner walls 71a and 71b. A number of slits are formed
in portions of the inner walls 71a and 71b below the substrate
mounting tables 61a and 61b, respectively, so that the exhaust
mechanism 15 can exhaust the interior of the chamber 10 from both
the processing parts 11a and 11b. Thus, the interiors of the
processing parts 11a and 11b are exhausted by the exhaust mechanism
15 at the same time. The APC 102 and the vacuum pump 103 are shared
by both the processing parts 11a and 11b.
[0051] In addition, in order to measure the internal pressure of
the chamber 10, a high-pressure capacitance manometer 105a and a
low-pressure capacitance manometer 105b, which are pressure gauges,
are installed so as to be inserted into the exhaust spaces 68 from
the bottom portion 51b of the chamber 10, respectively. The opening
degree of the automatic pressure control valve (APC) 102 is
controlled based on a pressure detected by the capacitance
manometer 105a or 105b.
[0052] The control part 16 includes a process controller 161
provided with a microprocessor (computer) for controlling various
components of the COR processing apparatus 100. A user interface
162 is connected to the process controller 161. The user interface
162 includes a keyboard or a touch panel display for allowing an
operator to input commands to manage the COR processing apparatus
100, a display for visualizing and displaying the operation status
of the COR processing apparatus 100, and the like. In addition, a
storage part 163 is connected to the process controller 161. The
storage part 163 stores a control program for realizing various
processes executed in the COR processing apparatus 100 under the
control of the process controller 161, processing recipes which are
control programs for causing the various components of the COR
processing apparatus 100 to execute their respective prescribed
processes according to processing conditions, various databases and
the like. The processing recipes are stored in an appropriate
storage medium (not shown) in the storage part 163. Then, as
necessary, any of the processing recipes is called from the storage
part 163 and is executed by the process controller 161, so that a
desired process is performed in the COR processing apparatus 100
under the control of the process controller 161.
[0053] Further, in the present embodiment, the control part 16 has
a significant feature in that the MFCs 150a to 150h and the
opening/closing valves 151a to 151h of the gas supply mechanism 14
are independently controlled as described above.
<Substrate Processing Operation>
[0054] Next, a substrate processing operation performed by such a
substrate processing device will be described. FIGS. 3A and 3B are
sectional views for explaining a substrate processing operation
performed by the COR processing apparatus 100 according to an
embodiment.
[0055] Two wafers Wa and Wb on each of which an etching target film
(for example, SiO.sub.2 film) has been formed are respectively
loaded into the processing parts 11a and 11b inside the chamber 10,
and are respectively mounted on the substrate mounting tables 61a
and 61b. Then, a pressure stabilizing step of stabilizing the
internal pressure of the chamber 10 by adjusting the internal
pressure to a predetermined pressure by means of the exhaust
mechanism 15 is performed, and subsequently, a substrate process
step is performed. Since the processing parts 11a and 11b share the
exhaust mechanism 15, the pressure adjustment during the pressure
stabilizing step and the substrate process step is performed by the
common automatic pressure control valve (APC) 102.
[0056] The substrate process step is performed with a common
substrate processing mode illustrated in FIG. 3A and an independent
substrate processing mode illustrated in FIG. 3B.
(Common Substrate Processing Mode)
[0057] The common substrate processing mode is a mode in which the
wafers Wa and Wb are processed under the same gas conditions. With
this common substrate processing mode, a COR process is performed
in both the processing parts 11a and 11b. In this mode, the state
of the opening/closing valves 151a to 151h corresponds to "Case a"
described above. Thus, as illustrated in FIG. 3A, the HF gas and
the NH.sub.3 gas respectively diluted with the Ar gas and the
N.sub.2 gas as inert gases are supplied from the gas introduction
members 12a and 12b onto the wafers Wa and Wb, whereby the same
substrate process is performed on both the wafers Wa and Wb.
(Independent Substrate Processing Mode)
[0058] The independent substrate processing mode is a mode in which
the wafers Wa and Wb are processed under different gas conditions.
In this mode, the state of the opening/closing valves 151a to 151h
corresponds to, for example, "Case b" described above. Thus, as
illustrated in FIG. 3B, the HF gas and the NH.sub.3 gas
respectively diluted with the Ar gas and the N.sub.2 gas are
supplied from the gas introduction member 12a onto the wafer Wa of
the processing part 11a, and only the Ar gas and the N.sub.2 gas
are supplied from the gas introduction member 12b onto the wafer Wb
of the processing part 11b, whereby different substrate processes
are performed on the wafers Wa and Wb. That is to say, the
processing of the wafer Wa by the HF gas and the NH.sub.3 gas is
continued in the processing part 11a, whereas the supply of the HF
gas and the NH.sub.3 gas onto the wafer Wb is stopped in the
processing part 11b. At this time, only the HF gas may be stopped
and the NH.sub.3 gas may be supplied to the processing part 11b. An
inert gas supplied from the gas introduction member 12b may be one
of the Ar gas and the N.sub.2 gas.
[0059] In the independent substrate processing mode, contrary to
FIG. 3B, the processing of the wafer Wb by the HF gas and the
NH.sub.3 gas may be performed in the processing part 11b, whereas
the supply of the HF gas and the NH.sub.3 gas onto the wafer Wa may
be stopped in the processing part 11a. In this case, the state of
the opening/closing valves 151a to 151h corresponds to, for
example, "Case c" described above. At this time, the supply of the
HF gas to the processing part 11a may be stopped, and the NH.sub.3
gas may be supplied to the processing part 11a. An inert gas
supplied from the gas introduction member 12a may be one of the Ar
gas and the N.sub.2 gas.
[0060] When it is desired to make a timing of the COR processing
different between the processing part 11a and the processing part
11b, the independent substrate processing mode is a mode in which
processing is performed in one processing part and no processing is
performed in the other processing part.
[0061] When the independent substrate processing mode is applied in
such a manner that the COR process is performed in the processing
part 11b and no COR process is performed in the processing part
11b, it may be considered to stop the supply of a gas from the gas
introduction member 12b to the processing part 11b, as a reference
example illustrated in FIG. 4. However, since the exhaust mechanism
15 is shared by both the processing parts 11a and 11b and the
pressure is controlled by the single APC, if the supply of a gas
from the gas introduction member 12b is stopped while continuing to
supply the HF gas and the NH.sub.3 gas from the gas introduction
member 12a, a pressure difference occurs between the processing
part 11a and the processing part 11b. Therefore, even when the
process spaces S of the processing parts 11a and 11b are
substantially sealed, the gas from the gas introduction member 12a
flows backward through slits formed in the lower portions of the
inner walls 71a and 71b and flows into the processing portion 11b.
This makes it difficult to completely stop the processing of the
wafer Wb by the HF gas and the NH.sub.3 gas in the processing part
11b. For this reason, in the independent substrate processing mode,
the Ar gas and the N.sub.2 gas are supplied from the gas
introduction member 12b, as illustrated in FIG. 3B. However, if the
flow rates of the Ar gas and the N.sub.2 gas are equal to those in
the processing part 11a, the total flow rate decreases, which also
generates a pressure difference to cause a backward flow. This
makes it difficult to stop the processing completely. Therefore, in
the present embodiment, in the case where the processing is
performed in the independent substrate processing mode, the gas
supply mechanism 14 controls the flow rates of the Ar gas and the
N.sub.2 gas from the gas introduction member 12b so as to prevent a
pressure difference from occurring between the processing part 11a
and the processing part 11b.
[0062] For example, the control part 16 can control the gas supply
mechanism so that the pressure of the processing part 11a and the
pressure of the processing part 11b become equal to each other so
as to prevent the pressure difference from occurring between the
processing part 11a and the processing part 11b by closing the
opening/closing valves 151d and 151h to stop the supply of the HF
gas and the NH.sub.3 gas to the gas introduction member 12b and
increasing the flow rates of the Ar gas and the N.sub.2 gas by
means of the MFCs 150b and 150f with the opening/closing valves
151b and 151f opened. That is to say, the Ar gas and the N.sub.2
gas are used as supplement gases for pressure regulation. As
described above, in the independent substrate processing mode, the
NH.sub.3 gas may be supplied to the processing part 11b which
performs no processing, but in that case, only the Ar gas may be
used as the supplement gas.
[0063] In this manner, for one of the processing parts 11a and 11b,
which is intended to stop the substrate process, the pressure
regulation is performed by supplying an inert gas as a supplement
gas for pressure regulation rather than simply stopping the supply
of a processing gas. Thus, even when the exhaust of gases from both
the processing parts 11a and 11b by the single exhaust mechanism 15
is performed at the same time, it is possible to prevent the inflow
of gas between the processing parts 11a and 11b.
(One Example of Process Sequence)
[0064] In this example, as illustrated in a flow chart of FIG. 5,
after a pressure stabilizing step S1 for stabilizing a pressure, a
substrate process step (COR process) S2 is performed in combination
of the processing in the common substrate processing mode and the
processing in the independent substrate processing mode, and then
an exhausting step S3 for exhausting a process space is performed.
In performing the substrate process step S2, the independent
substrate processing mode-based process S2-1 is initially performed
and subsequently the common substrate processing mode-based process
S2-2 is performed.
[0065] In the substrate process step S2, when the common substrate
processing mode-based process S2-2 is initially performed and the
independent substrate processing mode-based process S2-1 is then
performed, even if a processing gas to be supplied to a processing
part in which the processing is paused is switched to a supplement
gas, etching (COR process) may proceed due to a reaction product
and a residual gas on the wafer when the processing is paused under
high pressure conditions.
[0066] Therefore, in this example, when performing the substrate
process step S2 followed by the pressure stabilizing step S1, the
independent substrate processing mode-based process S2-1 is first
performed and subsequently the common substrate processing
mode-based process S2-2 is performed. Thus, it is possible to
eliminate the influence of a reaction product and a residual gas,
thereby improving the control accuracy of the etching amount.
[0067] In the transition from the independent substrate processing
mode-based process S2-1 to the common substrate processing
mode-based process S2-2, as described above, in the processing part
11b, the HF gas and the NH.sub.3 gas as processing gases are
introduced while the Ar gas and the N.sub.2 gas are being supplied,
or the HF gas is introduced while the Ar gas, the N.sub.2 gas and
the NH.sub.3 gas are being supplied. As such, an etching delay may
occur when the flow rate of the Ar gas or the N.sub.2 gas is large.
In such a case, a processing time may be adjusted in anticipation
of the etching delay in advance.
[0068] As described above, the substrate process step S2 is ended
by performing the independent substrate processing mode-based
process S2-2 followed by the common substrate processing mode-based
process S2-2. In some embodiments, after the common substrate
processing mode-based process S2-2, the independent substrate
processing mode-based process S2-1 and the common substrate
processing mode-based process S2-2 may be repeated while performing
a purging process between the process S2-1 and the process
S2-2.
[0069] A specific gas flow control in this example will be
described with reference to a timing chart of FIG. 6. First, the
opening/closing valves 151a, 151b, 151e, 151f, 151g and 151h are
opened so that the Ar gas, the N.sub.2 gas and the NH.sub.3 gas are
supplied to the processing parts 11a and 11b at the predetermined
same flow rates to adjust internal pressures of the processing
parts 11a and 11b to a predetermined pressure, thereby stabilizing
the internal pressures (in the pressure stabilizing step S1).
[0070] At the point of time when the pressure is stabilized, the
substrate process is started (in the substrate process step S2). In
the substrate process step S2, first, the opening/closing valve
151c is opened to supply the HF gas to the processing part 11a to
start the COR process in the processing part 11a, and then the
independent substrate processing mode-based process S2-1 with no
COR process is performed for a predetermined period of time without
supplying the HF gas to the processing part 11b. At this time,
since the HF gas is not supplied to the processing part 11b, the Ar
gas of the processing part 11b is increased in flow rate more than
that of the processing part 11a so that the processing part 11b has
the same internal pressure as the processing part 11a. The Ar gas
of the increased flow rate serves as a supplement gas. The increase
in amount of the Ar gas (the flow rate of the supplement gas) may
correspond to the amount of the HF gas supplied to the processing
part 11a.
[0071] After the predetermined period of time, the COR process is
continued in the processing part 11a while maintaining all the
gases at the same flow rates, and the common substrate processing
mode-based process S2-2 with the COR process is performed in the
processing part 11b for a predetermined period of time by opening
the opening/closing valve 151d to supply the HF gas to the
processing part 11b. At this time, in the processing part 11b, the
flow rate of the Ar gas supplied in the independent substrate
processing mode-based process S2-1 is decreased so that the
processing part 11b has the same internal pressure as the
processing part 11a. In this case, the decrease in the amount of
the Ar gas may correspond to the amount of the HF gas supplied to
the processing part 11b.
[0072] After the substrate process step S2 is completed, all the
opening/closing valves are closed to stop the supply of the gases
and the process spaces S are exhausted by the exhaust mechanism 15
(in the exhausting step S3).
[0073] In the example of FIG. 6, the HF gas is not introduced into
the processing part 11b in the independent substrate processing
mode-based process S2-1, but the HF gas is introduced into the
processing part 11b in the common substrate processing mode-based
process S2-2. In some embodiments, the HF gas and the NH.sub.3 gas
may not be introduced into the processing part 11b in the
independent substrate processing mode-based process S2-1, but the
HF gas and the NH.sub.3 gas may be introduced into the processing
part 11b when switching to the common substrate processing
mode-based process S2-2. In this case, in the independent substrate
processing mode-based process S2-1, the supplement gases to be
supplied to the processing part 11b may be the Ar gas and the
N.sub.2 gas.
[0074] The result of confirming the effects of the method of this
example will be described. Here, etching (COR process) was
performed by the processing apparatus of FIG. 1. First, a
processing recipe for cyclically etching a CVD-SiO.sub.2 film in 6
sec.times.8 cycle was used to evaluate an etching result for a case
(process A) where the etching was performed in the order of the
common substrate processing mode.fwdarw.the independent substrate
processing mode in each cycle and a case (process B) where the
etching was performed in the order of the independent substrate
processing mode.fwdarw.the common substrate processing mode in each
cycle. As described above, the Ar gas, the HF gas, the N.sub.2 gas
and the NH.sub.3 gas were supplied to both the processing parts 11a
and 11b to perform the COR process in the common substrate
processing mode, and the COR process was performed in only the
processing part 11a in the independent substrate processing mode
without supplying the HF gas to the processing part 11b. That is to
say, in the process A, the COR process was initially performed and
subsequently the process was stopped in the processing part 11b in
each cycle, whereas, in the processing B, the COR process was
performed after initially stopping the process for a predetermined
period of time in the processing part 11b in each cycle.
[0075] As a result, in the process A, the etching amount was +36.6%
for the target, whereas, in the processing B, the etching amount
was -10.4% for the target. From this fact, it was confirmed that
the controllability of the etching amount is improved by initially
performing the independent substrate processing mode-based process
and then performing the common substrate processing mode-based
process.
[0076] Next, a processing recipe for cyclically etching a thermal
oxide film in 15 sec.times.5 cycle was used to evaluate an etching
result for a case (process C) where the etching was performed in
the order of the common substrate processing mode.fwdarw.the
independent substrate processing mode in each cycle and a case
(process D) where the etching was performed in the order of the
independent substrate processing mode.fwdarw.the common substrate
processing mode in each cycle.
[0077] As a result, in the process C, the etching amount was +12.7%
for the target, whereas, in the process D, the etching amount was
-5.0% for the target. Similarly in the thermal oxide film, from
this fact, it was confirmed that the controllability of the etching
amount is improved by initially performing the independent
substrate processing mode-based process and then performing the
common substrate processing mode-based process.
(Another Example of Process Sequence)
[0078] In the aforementioned example of the process sequence, in
the independent substrate processing mode-based process S2-1, the
Ar gas and the N.sub.2 gas are increased to function as supplement
gases in the processing part to which the processing gases (the HF
gas and the NH.sub.3 gas) are not supplied, so that a pressure
difference is prevented from occurring between the processing part
11a and the processing part 11b. This prevents the inflow of the
gases between the processing parts 11a and 11b. However, since the
processing parts 11a and 11b are interconnected via the slits
formed in the portions of the inner walls 71a and 71b below the
substrate mounting tables 61a and 61b, it is difficult to
completely prevent a backward flow of the processing gases (the HF
gas and the NH.sub.3 gas) from one processing part to the other
processing part and completely prevent a backward flow of the
supplement gases (the Ar gas and the N.sub.2 gas) from the other
processing part to one processing part. Thus, a backward flow of
tiny amounts of gases (gas backward diffusion) occurs. When the
flow rates of the processing gases are equal to or higher than a
certain level, such a backward flow of tiny amounts of gases does
not greatly affect the etching amount, which makes it possible to
realize a process with a desired etching amount in the processing
parts 11a and 11b. However, in the process of a low flow rate
region, the influence of such a gas backward flow cannot be ignored
and a deviation from a set etching amount becomes large, which may
make it impossible to perform a desired process in the processing
parts 11a and 11b independently of each other.
[0079] On the other hand, if the flow rates of the processing gases
(the HF gas and the NH.sub.3 gas) and the supplement gases (the Ar
gas and the N.sub.2 gas) are increased in order to avoid such a
problem, the etching rate increases and it is therefore necessary
to adjust the etching amount with the processing time and the gas
flow rate, which may result in a narrow process margin.
[0080] Therefore, in this example, during the pressure stabilizing
step S1, a pressure regulating gas is flowed at a sufficient flow
rate to prevent the processing gases and the supplement gases from
backwardly diffusing between the processing parts 11a and 11b in
the independent substrate processing mode-based process S2-2 of the
subsequent substrate process step S2, and to form a flow of gas
flowing from the gas introducing members 12a and 12b to the exhaust
mechanism 15. This effectively prevents the backward flow (backward
diffusion) of gases in the low flow rate region in the independent
substrate processing mode-based process S2-2 of the substrate
process step S2.
[0081] Specifically, as illustrated in a timing chart of FIG. 7,
the Ar gas, the N.sub.2 gas and the NH.sub.3 gas are supplied as
the pressure regulating gases to both the processing parts 11a and
11b during the pressure stabilizing step S1. The flow rates of the
Ar gas, the N.sub.2 gas and the NH.sub.3 gas are set to be larger
than those in the substrate process step S2. In this case, the
total flow rate of the pressure regulating gases may be three times
or more as large as that in the substrate process step S2. As the
pressure regulating gas, a portion of the gases supplied during the
substrate process step S2, which does not cause substrate process,
may be used. As in the example of FIG. 6, as the pressure
regulating gases, the Ar gas, the N.sub.2 gas and the NH.sub.3 gas
may be used in the processing part 11a, and the Ar gas and the
N.sub.2 gas may be used in the processing part 11b.
[0082] In this example, in the subsequent substrate process step
S2, in the independent substrate processing mode-based process
S2-1, the flow rates of the Ar gas, the N.sub.2 gas and the
NH.sub.3 gas are decreased until reaching a normal state, and the
HF gas is supplied at a predetermined flow rate to perform the COR
process in the processing part 11a, whereas the flow rates of the
N.sub.2 gas and the NH.sub.3 gas in the processing part 11b are set
to be equal to those in the processing part 11a. The supply amount
of the Ar gas is adjusted so as to include a supplement gas
corresponding to the HF gas supplied to the processing part 11a. In
the subsequent common substrate processing mode-based process S2-2,
the HF gas is also supplied to the processing part 11b, the flow
rate of the Ar gas supplied as a supplement gas is reduced by the
supply amount of the HF gas. Thus, the COR process is performed in
the processing parts 11a and 11b under the same processing
conditions. Thereafter, the supply of the gases is stopped and the
exhausting step S3 is performed to exhaust the process spaces S by
the exhaust mechanism 15.
[0083] Thus, in the low flow rate region, in the independent
substrate processing mode-based process S2-2, it is possible to
prevent the backward flow of the processing gases and the
supplement gases more effectively than that in a case of only
adjusting the pressure with the supplement gases. More
specifically, even in the low flow rate region, it is possible to
extremely effectively prevent the processing gases (the HF gas and
the NH.sub.3 gas) from flowing backward from the processing part
11a to the processing part 11b intended to stop the process, and
also prevent the supplement gases (the Ar gas and the N.sub.2 gas)
from flowing backward from the processing part 11b to the
processing part 11a intended to continue the process. It is
therefore possible to perform the substrate process so that the
etching amount is close to the etching amount set in both the
processing parts 11a and 11b.
[0084] In the example of FIG. 7, the HF gas is not introduced into
the processing part 11b in the independent substrate processing
mode-based process S2-1, whereas the HF gas is introduced into the
processing part 11b in the common substrate processing mode-based
process S2-2. However, the HF gas and the NH.sub.3 gas may not be
introduced into the processing part 11b in the independent
substrate processing mode-based process S2-1. The HF gas and the
NH.sub.3 gas may be introduced into the processing part 11b when
switching to the common substrate processing mode-based process
S2-2. In this case, in the independent substrate processing
mode-based process S2-1, the supplement gases supplied to the
processing part 11b may be the Ar gas and the N.sub.2 gas.
[0085] The effects achieved when the flow rate of the pressure
regulating gas is actually increased in the pressure stabilizing
step will be described with reference to FIG. 8. Here, after
performing the pressure stabilizing step using the apparatus of
FIG. 1, the COR process was initially performed in the processing
part 11a in the substrate process step. The HF gas was not supplied
to the processing part 11b, and the independent substrate
processing mode-based process was performed to supplement an Ar gas
as a supplement gas at a flow rate corresponding to the amount of
the not-supplied HF gas. Therefore, the COR process was performed
in both the processing parts in the common substrate processing
mode. FIG. 8 is a view illustrating the total gas flow rate during
the substrate process step and an etching amount deviation (a
difference between the actual etching amount and the set etching
amount) in the COR process in the processing part 11a. In FIG. 8, a
black circle indicates an etching amount deviation when the flow
rates of the pressure regulating gases (the Ar gas, the N.sub.2 gas
and the NH.sub.3 gas) in the pressure stabilizing step are set to
be equal to those in the substrate process step. The etching amount
deviation tends to be large in a region where the total flow rate
is low. The etching amount deviation is as large as about -0.33 nm
at the total flow rate of 300 sccm. On the other hand, a black
square indicates an etching amount deviation available when the
flow rates of the pressure regulating gases are tripled. In this
case, even when the total flow rate during the substrate process
step is 300 sccm, the etching amount deviation is about -0.03 nm,
which is very close to the set value. The effect of increasing the
flow rates of the pressure regulating gases was confirmed from this
fact.
[0086] As described above, when the COR process is performed on a
SiO.sub.2 film formed on a wafer using the HF gas and the NH.sub.3
gas, ammonium fluorosilicate ((NH.sub.4).sub.2SiF.sub.6: AFS) is
generated as a reaction product. Thus, the wafer processed in the
COR processing apparatus 100 is heat-treated in a heat treating
apparatus to decompose and remove the AFS.
[0087] As described above, according to the present embodiment, in
performing the COR process on the two wafers respectively in the
processing part 11a and the processing part 11b, while the exhaust
mechanism 15 is used in a collective manner, the process is
initially performed in only one of the processing part 11a and the
processing part 11b in the independent substrate processing mode,
and subsequently, the COR process is performed in the processing
parts in the common substrate processing mode under the same
conditions. This improves the controllability of the etching
amount.
Other Applications
[0088] Although the present disclosure has been described by way of
an embodiment, the present disclosure is not limited to the above
embodiment but various modifications can be made without departing
from the spirit and scope of the present disclosure.
[0089] While in the above embodiment, the HF gas and the NH.sub.3
gas have been described to be used to perform the COR process, the
COR process may be performed with only the HF gas or the NH.sub.3
gas by the substrate processing device of FIG. 1. For example, in a
case in which an HF gas diluted with an Ar gas is supplied to
perform the COR process, the opening/closing valves may be
controlled as shown in the following Case d. Specifically, the
independent substrate processing mode-based process may be
performed using the HF gas only in the processing part 11a.
Subsequently, with the opening/closing valves 151e, 151f, 151g and
151h closed, the opening/closing valves 151a, 151b, 151c and 151d
may be opened to supply the HF gas and the Ar gas to perform the
common substrate processing mode-based process.
TABLE-US-00004 [Case d] Supply system to gas introduction member
12a Opening/closing valve 151a (Ar) Opened Opening/closing valve
151c (HF) Opened Opening/closing valve 151e (N.sub.2) Closed
Opening/closing valve 151g (NH.sub.3) Closed Supply system to gas
introduction member 12b Opening/closing valve 151b (Ar) Opened
Opening/closing valve 151d (HF) Closed Opening/closing valve 151f
(N.sub.2) Closed Opening/closing valve 151h (NH.sub.3) Closed
[0090] In addition, the substrate processing device is not limited
to the COR processing apparatus 100 of FIG. 1 as long as it is
schematically configured as illustrated in FIG. 9 such that the
processing parts 11a and 11b are installed in a single common
chamber 10 and the exhaust mechanism 15 is shared by the processing
parts 11a and 11b installed inside the single common chamber
10.
[0091] Further, the present disclosure is limited to the
configuration of FIG. 9 where the processing parts 11a and 11b are
installed inside the single common chamber 10. As an example, as
illustrated in FIG. 10, the processing parts 11a and 11b may be
respectively installed inside separate chambers 10a and 10b, and
the exhaust mechanism 15 may be shared by the separate chambers 10a
and 10b.
[0092] While in the above embodiment, the Ar gas or the N.sub.2
gas, which is a dilution gas for diluting the processing gas such
as the HF gas or the NH.sub.3 gas, is used as a supplement gas for
pressure regulation, but the present disclosure is limited to
thereto. As an example, the supplement gas may be another inert
gas. In addition, the supplement gas for pressure regulation is not
limited to the inert gas but may be a non-reactive gas which is not
reactive with etching target films of processed wafers Wa and Wb.
Further, a reactive gas may be used as long as it can regulate the
pressure without affecting the process.
[0093] In the above embodiment, the dilution gas is used as a
supplement gas for pressure regulation together with the processing
gas during the substrate process. However, separately from the
dilution gas used together with the processing gas, a dedicated
supplement gas may be used. In this case, a dedicated supplement
gas supply source, a dedicated supplement gas supply pipe and
dedicated MFCs and dedicated opening/closing valves may be
additionally installed in the gas supply mechanism 14.
[0094] Further, in the above embodiment, a semiconductor wafer has
been described as an example of a target substrate. However, it is
obvious that the target substrate is not limited to the
semiconductor wafer in the principle of the present disclosure and
it is to be understood that it can be applied to different various
substrate processes.
[0095] Furthermore, in the above embodiment, the apparatus provided
with the two processing parts 11a and 11b as a plurality of
processing parts has been described as an example, but the number
of processing parts is not limited to two.
[0096] Moreover, in the above embodiment, the substrate processing
device of the present disclosure has been described to be applied
as the COR processing apparatus, but the substrate processing
device is not limited to the COR processing apparatus.
EXPLANATION OF REFERENCE NUMERALS
[0097] 10, 10a, 10b: chamber, 11a, 11b: processing part, 12a, 12b:
gas introduction member, 14: gas supply mechanism, 15: exhaust
mechanism, 16: control part, 71a, 71b: inner wall, 101: exhaust
pipe, 141: Ar gas supply source, 142: HF gas supply source, 143:
N.sub.2 gas supply source, 144: NH.sub.3 gas supply source, 145,
145a, 145b: HF gas supply pipe, 146a, 146b: supply pipe, 147, 147a,
147b: Ar gas supply pipe, 148, 148a, 148b: NH.sub.3 gas supply
pipe, 149, 149a, 149b: N.sub.2 gas supply pipe, 150a to 150h: mass
flow controller, 151a to 151h: opening/closing valve
* * * * *