U.S. patent application number 11/263033 was filed with the patent office on 2006-05-04 for substrate processing method, system and program.
This patent application is currently assigned to TOKYO ELECTRON LIMITED. Invention is credited to Noriyuki Iwabuchi, Seiichi Kaise, Shigeaki Kato, Hiroshi Nakamura, Akira Obi, Mariko Shibata, Takeshi Yokouchi.
Application Number | 20060090703 11/263033 |
Document ID | / |
Family ID | 36260372 |
Filed Date | 2006-05-04 |
United States Patent
Application |
20060090703 |
Kind Code |
A1 |
Kaise; Seiichi ; et
al. |
May 4, 2006 |
Substrate processing method, system and program
Abstract
A substrate processing method is used for a substrate processing
system having a substrate processing device and a substrate
transfer device. The substrate processing method includes a
substrate transfer step of transferring a substrate and a substrate
processing step of performing a predetermined process on the
substrate. The substrate transfer step and the substrate processing
step include a plurality of operations, and at least two operations
among the plurality of the operations are performed simultaneously.
Preferably, the substrate processing device includes an
accommodating chamber, a mounting table placed in the accommodating
chamber to be mounted thereon the substrate, and a heat transfer
gas supply line for supplying a heat transfer gas to a space
between the substrate mounted on the mounting table and the
mounting table.
Inventors: |
Kaise; Seiichi;
(Nirasaki-shi, JP) ; Iwabuchi; Noriyuki;
(Miyagi-gun, JP) ; Kato; Shigeaki; (Miyagi-gun,
JP) ; Nakamura; Hiroshi; (Nirasaki-shi, JP) ;
Yokouchi; Takeshi; (Miyagi-gun, JP) ; Shibata;
Mariko; (Miyagi-gun, JP) ; Obi; Akira;
(Nirasaki-shi, JP) |
Correspondence
Address: |
OBLON, SPIVAK, MCCLELLAND, MAIER & NEUSTADT, P.C.
1940 DUKE STREET
ALEXANDRIA
VA
22314
US
|
Assignee: |
TOKYO ELECTRON LIMITED
Tokyo
JP
|
Family ID: |
36260372 |
Appl. No.: |
11/263033 |
Filed: |
November 1, 2005 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
60635958 |
Dec 15, 2004 |
|
|
|
Current U.S.
Class: |
118/719 |
Current CPC
Class: |
H01L 21/67201 20130101;
H01J 37/32743 20130101; H01L 21/6831 20130101; H01L 21/67748
20130101 |
Class at
Publication: |
118/719 |
International
Class: |
C23C 16/00 20060101
C23C016/00 |
Foreign Application Data
Date |
Code |
Application Number |
Nov 1, 2004 |
JP |
2004-318451 |
Claims
1. A substrate processing method used for a substrate processing
system having a substrate processing device and a substrate
transfer device, comprising: a substrate transfer step of
transferring a substrate; and a substrate processing step of
performing a predetermined process on the substrate, wherein the
substrate transfer step and the substrate processing step include a
plurality of operations, and at least two operations among the
plurality of the operations are performed simultaneously.
2. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate; and a heat transfer gas supply line for
supplying a heat transfer gas to a space between the substrate
mounted on the mounting table and the mounting table, and wherein a
vacuum pumping operation for vacuum pumping the heat transfer gas
supply line and a transferring operation for transferring the
substrate into the accommodating chamber are performed
simultaneously.
3. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate; and elevation pins protruded from the
mounting table to move up and down the substrate, and wherein a pin
protruding operation for protruding the elevation pins and a
transferring operation for transferring the substrate into the
accommodating chamber are performed simultaneously.
4. The substrate processing method of claim 3, wherein a pin
moving-down operation for moving down the elevation pins and a
taking-out operation for taking the substrate out of the
accommodating chamber are performed simultaneously.
5. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; and
a pressure control unit for controlling a pressure in the
accommodating chamber, and wherein a taking-in operation for taking
the substrate into the accommodating chamber and a pressure-up
operation for increasing the pressure in the accommodating chamber
by the pressure control unit are performed simultaneously.
6. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate; a heat transfer gas supply line for
supplying a heat transfer gas to a space between the substrate
mounted on the mounting table and the mounting table; a high
frequency power supply for supplying a high frequency power to the
mounting table; and a gas flow rate control and supply unit for
controlling a flow rate of a desired gas to supply the desired gas
into the accommodating chamber, and wherein an application stopping
operation for stopping an application of the high frequency power
by the high frequency power supply, a gas supply stopping operation
for stopping a supply of the gas by the gas flow rate control and
supply unit, and a vacuum pumping operation for vacuum pumping the
heat transfer gas supply line are performed simultaneously.
7. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate; elevation pins protruded from the mounting
table to move up and down the substrate; a pressure control unit
for controlling a pressure in the accommodating chamber; and a gas
flow rate control and supply unit for controlling a flow rate of a
desired gas to supply the desired gas into the accommodating
chamber, and wherein a pin protruding operation for protruding the
elevation pins, a pressure-down operation for decreasing the
pressure in the accommodating chamber by the pressure control unit,
and a gas supply stopping operation for stopping a supply of the
gas by the gas flow rate control and supply unit are performed
simultaneously.
8. The substrate processing method of claim 1, wherein the
substrate processing device includes: a substrate counting unit of
an arm shape for counting the number of substrates accommodated in
a substrate accommodating unit, the substrate transfer device being
configured in a manner capable of being moved up and down, flexible
and extensible, and wherein, after counting the number of the
substrates accommodated in the substrate accommodating unit, an
elevating operation for moving up and down the substrate counting
unit and a contracting operation for contracting the substrate
counting unit are performed simultaneously.
9. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate, capable of moving up and down; and a
pressure control unit for controlling a pressure in the
accommodating chamber, and wherein a pressure-up operation for
increasing the pressure in the accommodating chamber by the
pressure control unit and a mounting table elevating operation for
moving up the mounting table are performed simultaneously.
10. The substrate processing method of claim 1, wherein a
pressure-down operation for decreasing the pressure in the
accommodating chamber by the pressure control unit and a mounting
table moving-down operation for moving down the mounting table are
performed simultaneously.
11. The substrate processing method of claim 1, wherein the
substrate processing device includes: an accommodating chamber; a
mounting table placed in the accommodating chamber to be mounted
thereon the substrate; elevation pins protruded from the mounting
table to move up and down the substrate; and a door unit capable of
being opened and closed for connecting the substrate transfer
device and the substrate processing device, and wherein a pin
protruding operation for protruding the elevation pins and a
closing operation for closing the door unit are performed
simultaneously.
12. A substrate processing system comprising: a substrate
processing device and a substrate transfer device, wherein the
substrate processing device and the substrate transfer device
include a plurality of elements, and, at least in case of
processing a substrate or transferring the substrate, at least two
elements among the plurality of the elements are operated
simultaneously.
13. A substrate processing program for making a computer perform a
substrate processing method used for a substrate processing system
having a substrate processing device and a substrate transfer
device, comprising: a substrate transferring module for
transferring a substrate; and a substrate processing module for
processing the substrate, wherein the substrate transferring module
and the substrate processing module include a plurality of
operations, and at least two of the plurality of the operations are
performed simultaneously.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This document claims priority to Japanese Patent Application
No. 2004-318451, filed on Nov. 1, 2004 and U.S. Provisional
Application No. 60/635,958, filed on Dec. 15, 2004, the entire
content of which are hereby incorporated by reference.
FIELD OF THE INVENTION
[0002] The present invention relates to a substrate processing
method, system and program; and, more particularly, to a substrate
processing method, system and program for transferring a substrate
to perform a desired process thereon.
BACKGROUND OF THE INVENTION
[0003] Conventionally, a substrate processing system for performing
a film forming process, an etching process or the like on a
semiconductor wafer (hereinafter, referred to as "wafer") as a
substrate includes a process module (hereinafter, referred to as
"PM") for receiving a wafer to perform a process thereon; an
atmospheric transfer unit for taking out a wafer from a wafer
cassette as a sealed chamber for storing a specified number of
wafers; and a load-lock chamber located between the atmospheric
transfer unit and the PM for transferring a wafer from the
atmospheric transfer unit to the PM or vice versa.
[0004] In the conventional substrate processing system, process
improvements of the individual devices included therein have been
made in order to enhance the throughput that is calculated by wafer
processing time. However, to meet the recent strong demands for a
further throughput enhancement, in addition to the process
improvements of the individual devices, active investigations are
carried out to find methods of enhancing the efficiency by
improving a coordination between the individual devices included in
the substrate processing system in view of OEE (Overall Equipment
Efficiency). In addition, to enhance the efficiency by improving
the coordination between the individual devices, an external device
for generally controlling the processes of the individual devices
in the substrate processing system is also being developed.
[0005] As an apparatus for enhancing the efficiency by improving
the coordination between the individual devices, there is known a
throughput adjusting device used for a semiconductor manufacturing
apparatus in which every process module has a gate valve that can
be opened and closed by an operation of an air cylinder, wherein
the semiconductor manufacturing apparatus is a single-wafer type
apparatus including a plurality of process modules and a CCU
(Central Control Unit) for controlling the operations of the
process modules (for example, see Japanese Laid-Open Application
No. H10-135093).
[0006] In this throughput adjusting device, a CPU in a CCU controls
an electronic valve of an air cylinder to be closed and a timer
counter T in a RAM in the CCU is operated to start to close a gate
valve and at the same time to measure an actual operation time T1.
Thereafter, when the gate valve is completely closed, the CPU
substitutes the time measured by the timer counter T for an
operation time T1, computes an idle time T2 by subtracting the
operation time T1 from an operation monitoring time T0 read out
from the RAM, and displays a current situation on a display in the
throughput adjusting device. Thus, an operator can measure the
operation time of devices easily and quickly, and the throughput of
the semiconductor manufacturing apparatus can be enhanced by using
the measured result and the like.
[0007] Furthermore, as a method of enhancing the efficiency by
improving the coordination between the individual devices, there is
known a method of determining manufacturing conditions by
determining the number of surplus cassettes during the
semiconductor manufacturing process, wherein a buffer size setting
device computes S, i.e., the number of surplus wafers, from an OEE
value calculated by using a specified formula based on the
throughput of the manufacturing apparatus, the total number of the
wafers, the time taken to mount and transfer the wafers, the number
of the wafers kept in cassettes and the number of the cassettes, so
that the number of the surplus cassettes are determined easily and
precisely based on the computed S value (for example, see Japanese
Laid-Open Application No. 2002-141255).
[0008] However, since the above-described device and method are to
compute or predict an amount of the throughput that can be
increased, they do not propose any substantial and specific
techniques for enhancing the throughput. In other words, the
above-described device and method propose little more than a
conventional way of enhancing the throughput such as reducing idle
times between individual steps during the manufacturing process
based on the computed or predicted amount of the throughput that
can be increased, and it is not possible to greatly enhance the
throughput by using them because, while a specified device performs
a specified operation, other devices not involved in the specified
operation merely wait until moments for them to start their
operations.
SUMMARY OF THE INVENTION
[0009] It is, therefore, an object of the present invention to
provide a substrate processing method, system and program capable
of greatly enhancing the throughput.
[0010] To achieve the object, in accordance with one aspect of the
present invention, there is provided a substrate processing method
used for a substrate processing system having a substrate
processing device and a substrate transfer device, including: a
substrate transfer step of transferring a substrate; and a
substrate processing step of performing a predetermined process on
the substrate, wherein the substrate transfer step and the
substrate processing step include a plurality of operations, and at
least two operations among the plurality of the operations are
performed simultaneously.
[0011] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table (such as a susceptor or a
pedestal) placed in the accommodating chamber to be mounted thereon
the substrate; and a heat transfer gas supply line for supplying a
heat transfer gas to a space between the substrate mounted on the
mounting table and the mounting table, wherein a vacuum pumping
operation for vacuum pumping the heat transfer gas supply line and
a transferring operation for transferring the substrate into the
accommodating chamber are performed simultaneously.
[0012] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table placed in the accommodating
chamber to be mounted thereon the substrate; and elevation pins
protruded from the mounting table to move up and down the
substrate, wherein a pin protruding operation for protruding the
elevation pins and a transferring operation for transferring the
substrate into the accommodating chamber are performed
simultaneously.
[0013] Preferably, in the above-described substrate processing
method, a pin moving-down operation for moving down the elevation
pins and a taking-out operation for taking the substrate out of the
accommodating chamber are performed simultaneously.
[0014] Preferably, the substrate processing device includes: an
accommodating chamber; and a pressure control unit for controlling
a pressure in the accommodating chamber, wherein a taking-in
operation for taking the substrate into the accommodating chamber
and a pressure-up operation for increasing the pressure in the
accommodating chamber by the pressure control unit are performed
simultaneously.
[0015] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table placed in the accommodating
chamber to be mounted thereon the substrate; a heat transfer gas
supply line for supplying a heat transfer gas to a space between
the substrate mounted on the mounting table and the mounting table;
a high frequency power supply for supply a high frequency power to
the mounting table; and a gas flow rate control and supply unit for
control a flow rate of a desired gas to supply the desired gas into
the accommodating chamber, wherein an application stopping
operation for stopping an application of the high frequency power
by the high frequency power supply, a gas supply stopping operation
for stopping a supply of the gas by the gas flow rate control and
supply unit, and a vacuum pumping operation for vacuum pumping the
heat transfer gas supply line are performed simultaneously.
[0016] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table placed in the accommodating
chamber to be mounted thereon the substrate; elevation pins
protruded from the mounting table to move up and down the
substrate; a pressure control unit for controlling a pressure in
the accommodating chamber; and a gas flow rate control and supply
unit for control a flow rate of a desired gas to supply the desired
gas into the accommodating chamber, wherein a pin protruding
operation for protruding the elevation pins, a pressure-down
operation for decreasing the pressure in the accommodating chamber
by the pressure control unit, and a gas supply stopping operation
for stopping a supply of the gas by the gas flow rate control and
supply unit are performed simultaneously.
[0017] Preferably, the substrate processing device includes: a
substrate counting unit of an arm shape for counting the number of
substrates accommodated in a substrate accommodating unit, the
substrate transfer device being configured in a manner capable of
being moved up and down, flexible and extensible, wherein, after
counting the number of the substrates accommodated in the substrate
accommodating unit, an elevating operation for moving up and down
the substrate counting unit and a contracting operation for
contracting the substrate counting unit are performed
simultaneously.
[0018] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table placed in the accommodating
chamber to be mounted thereon the substrate, capable of moving up
and down; and a pressure control unit for controlling a pressure in
the accommodating chamber, wherein a pressure-up operation for
increasing the pressure in the accommodating chamber by the
pressure control unit and a mounting table elevating operation for
moving up the mounting table are performed simultaneously.
[0019] Preferably, in the above-described substrate processing
method, a pressure-down operation for decreasing the pressure in
the accommodating chamber by the pressure control unit and a
mounting table moving-down operation for moving down the mounting
table are performed simultaneously.
[0020] Preferably, the substrate processing device includes: an
accommodating chamber; a mounting table placed in the accommodating
chamber to be mounted thereon the substrate; elevation pins
protruded from the mounting table to move up and down the
substrate; and a door unit capable of being opened and closed for
connecting the substrate transfer device and the substrate
processing device, wherein a pin protruding operation for
protruding the elevation pins and a closing operation for closing
the door unit are performed simultaneously.
[0021] In accordance with another aspect of the present invention,
there is provided a substrate processing system including: a
substrate processing device and a substrate transfer device,
wherein the substrate processing device and the substrate transfer
device include a plurality of elements, and, at least in case of
processing a substrate or transferring the substrate, at least two
elements among the plurality of the elements are operated
simultaneously.
[0022] In accordance with still another aspect of the present
invention, there is provided a substrate processing program for
making a computer perform a substrate processing method used for a
substrate processing system having a substrate processing device
and a substrate transfer device, comprising: a substrate
transferring module for transferring a substrate; and a substrate
processing module for processing the substrate, wherein the
substrate transferring module and the substrate processing module
include a plurality of operations, and at least two of the
plurality of the operations are performed simultaneously.
[0023] In accordance with the present invention, the substrate
transferring step and the substrate processing step include the
plurality of the operations, and at least two operations among the
plurality of the operations included in the substrate transferring
step or the substrate processing step are carried out
simultaneously. Therefore, while a specified element of the
substrate transferring device or the substrate processing device
performs a specified operation, other elements not involved in the
specified operation performs their own operations, thereby reducing
the time needed for processing the substrate. Thus, the throughput
can be enhanced greatly.
[0024] Further, the vacuum pumping operation for vacuum pumping the
heat transfer gas supply line and the transferring operation for
transferring the substrate into the accommodating chamber are
performed simultaneously. Thus, the throughput can be enhanced
markedly.
[0025] Still further, the pin protruding operation for protruding
the elevation pins and the transferring operation for transferring
the substrate into the accommodating chamber are performed
simultaneously. Thus, the throughput can be enhanced greatly.
[0026] Still further, the pin moving-down operation for moving down
the elevation pins and the taking-out operation for taking the
substrate out of the accommodating chamber are performed
simultaneously. Thus, the throughput can be enhanced greatly.
[0027] Still further, the taking-in operation for taking the
substrate into the accommodating chamber and the pressure-up
operation for increasing the pressure in the accommodating chamber
by the pressure control unit are performed simultaneously. Thus,
the throughput can be enhanced markedly.
[0028] Still further, the application stopping operation for
stopping an application of the high frequency power by the high
frequency power supply, the gas supply stopping operation for
stopping a supply of the gas by the gas flow rate control and
supply unit, and the vacuum pumping operation for vacuum pumping
the heat transfer gas supply line are performed simultaneously.
Thus, the throughput can be enhanced greatly.
[0029] Still further, the pin protruding operation for protruding
the elevation pins, the pressure-down operation for decreasing the
pressure in the accommodating chamber by the pressure control unit,
and the gas supply stopping operation for stopping a supply of the
gas by the gas flow rate control and supply unit are performed
simultaneously. Thus, the throughput can be enhanced greatly.
[0030] Still further, the elevating operation for moving up and
down the substrate counting unit and the contracting operation for
contracting the substrate counting unit are performed
simultaneously. Thus, the throughput can be enhanced
significantly.
[0031] Still further, the pressure-up operation for increasing the
pressure in the accommodating chamber by the pressure control unit
and the mounting table elevating operation for moving up the
mounting table are performed simultaneously. Thus, the throughput
can be enhanced greatly.
[0032] Still further, the pressure-down operation for decreasing
the pressure in the accommodating chamber by the pressure control
unit and the mounting table moving-down operation for moving down
the mounting table are performed simultaneously. Thus, the
throughput can be enhanced markedly.
[0033] Still further, a pin protruding operation for protruding the
elevation pins and a closing operation for closing the door unit
are performed simultaneously. Thus, the throughput can be enhanced
greatly.
[0034] Still further, at least in case of processing a substrate or
transferring the substrate, at least two elements among the
plurality of the elements are operated simultaneously. Thus, the
throughput can be enhanced greatly.
[0035] Still further, the substrate transferring module and the
substrate processing module include the plurality of the
operations, and at least two operations among the plurality of the
operations included in the substrate transferring module or the
substrate processing module are carried out simultaneously.
Therefore, while a specified element of the substrate transferring
device or the substrate processing device performs a specified
operation, other elements not involved in the specified operation
performs their own operations, thereby reducing the time needed for
processing the substrate. Thus, the throughput can be enhanced
greatly.
BRIEF DESCRIPTION OF THE DRAWINGS
[0036] The above and other objects and features of the present
invention will become apparent from the following description of a
preferred embodiment, given in conjunction with the accompanying
drawings, in which:
[0037] FIG. 1 shows a cross sectional view representing a
conceptual configuration of a substrate processing system in
accordance with the preferred embodiment.
[0038] FIG. 2 illustrates a conceptual configuration of the PM
shown in FIG. 1.
[0039] FIG. 3 is a cross sectional view depicting a conceptual
configuration of another PM that can be connected to the LL in the
substrate processing system shown in FIG. 1.
[0040] FIG. 4 provides a flow chart describing a wafer processing
in accordance with the substrate processing method of the preferred
embodiment. Hereinafter, the process will be described as to a case
where the LL 4 is connected to the PM 2 in the substrate processing
system 1.
[0041] FIG. 5 represents a sequence chart describing a first
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of transferring
the wafer W into the chamber 10 shown in FIG. 4.
[0042] FIGS. 6A to 6D present sequence charts describing a second
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of transferring
the wafer W into the chamber 10 shown in FIG. 4.
[0043] FIGS. 7A and 7B depict sequence charts respectively
describing a first and a second example of the substrate processing
method in accordance with the preferred embodiment, respectively
applied to the step of transferring the wafer W into the chamber 10
and the step of transferring the wafer W out of the chamber 10
shown in FIG. 4.
[0044] FIG. 8 shows a sequence chart for illustrating a third
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of taking the wafer W
into the chamber 10 shown in FIG. 4.
[0045] FIG. 9 illustrates a sequence chart for illustrating a
fourth example of the substrate processing method in accordance
with the preferred embodiment, that is applied to the step of
transferring the wafer W into the chamber 10 shown in FIG. 4.
[0046] FIG. 10 presents a sequence chart for depicting the first
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of vacuum pumping
the backside shown in FIG. 4.
[0047] FIG. 11 provides a sequence chart for describing the fifth
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of taking the
wafer into the chamber shown in FIG. 4.
[0048] FIG. 12 is a sequence chart for showing the first example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the STEP0 shown in FIG. 4.
[0049] FIG. 13 illustrates a sequence chart for explaining a sixth
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of taking the
wafer into the chamber shown in FIG. 4.
[0050] FIG. 14 is a sequence chart for showing an example of a case
where the wafer W is transferred between the LL and the atmospheric
transfer unit.
[0051] FIG. 15 depicts a sequence chart for showing a second
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of taking the
wafer out of the chamber shown in FIG. 4.
[0052] FIG. 16 provides a sequence chart for showing the first
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the STEP2 shown in FIG.
4.
[0053] FIG. 17 shows a conceptual configuration of the heat
transfer gas supply unit in the substrate processing apparatus
shown in FIG. 2.
[0054] FIG. 18 shows a sequence chart for illustrating a valve
control of the heat transfer gas supply unit shown in FIG. 18.
[0055] FIG. 19 provides a sequence chart for depicting the second
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the STEP2 shown in FIG.
4.
[0056] FIG. 20 provides a sequence chart for depicting the first
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the STEP1 shown in FIG.
4.
[0057] FIG. 21 is a sequence chart for showing the second example
of the substrate processing method in accordance with the preferred
embodiment, that is applied to the STEP1 shown in FIG. 4.
[0058] FIG. 22 depicts a sequence chart for representing the second
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of the vacuum
pumping of the backside shown in FIG. 4.
[0059] FIG. 23 presents a sequence chart for providing a seventh
example of the substrate processing method applied to the step of
taking the wafer into the chamber and a third example of the step
of taking the wafer out of the chamber shown in FIG. 4 in
accordance with the preferred embodiment.
[0060] FIG. 24 represents a flow chart of the wafer replacement
process in accordance with the preferred embodiment.
[0061] FIG. 25 is a sequence chart of the wafer replacement process
shown in FIG. 24.
[0062] FIGS. 26A to 26C present sequence diagrams for illustrating
the eighth example of the substrate processing method applied to
the step of taking the wafer into the chamber and a fourth example
of the step of taking the wafer out of the chamber shown in FIG. 4
in accordance with the preferred embodiment.
[0063] FIG. 27 provides a sequence chart for depicting the third
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the STEP1 shown in FIG.
4.
[0064] FIG. 28 is a sequence chart for showing the fifth example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the step of taking the wafer out of
the chamber shown in FIG. 4.
[0065] FIG. 29 represents a sequence chart for describing the sixth
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of taking the
wafer out of the chamber shown in FIG. 4.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENT
[0066] Hereinafter, a preferred embodiment will be described with
reference to the drawings.
[0067] First, a substrate processing system and a substrate
transferring method in accordance with the preferred embodiment
will be explained.
[0068] FIG. 1 shows a cross sectional view representing a
conceptual configuration of a substrate processing system in
accordance with the preferred embodiment.
[0069] Referring to FIG. 1, a substrate processing system 1
includes a process module (hereinafter, referred to as "PM") 2 for
performing various kinds of processes such as a film-forming
process, a diffusion process and an etching process on every single
semiconductor wafer W as a substrate; an atmospheric transfer unit
3 for taking out the semiconductor wafer W from a wafer cassette 40
storing a specified number of the semiconductor wafers W; a
load-lock chamber (hereinafter, referred to as "LL") 4 located
between the atmospheric transfer unit 3 and the PM 2 for loading
and unloading the semiconductor wafer W from the atmospheric
transfer unit 3 to the PM 2 or vice versa.
[0070] The insides of the PM 2 and the LL 4 are configured such
that they can be vacuum pumped, and the inside of the atmospheric
transfer unit 3 is always kept at an atmospheric pressure. The PM 2
is connected to the LL 4 via a gate valve 5, and the LL 4 is
connected to the atmospheric transfer unit 3 via a gate valve 6.
The gate valves 5 and 6 can be freely opened and closed, so that
the PM 2 and the LL 4 can be made to communicate with each other or
to be isolated from each other by the valve 5 and likewise, the LL
4 and the atmospheric transfer unit 3 can be made to communicate
with each other or to be isolated from each other by the valve 6.
Further, the inside of the LL 4 is connected to the inside of the
atmospheric transfer unit 3 via a communication pipe 8 having a
valve 7 that can be opened and closed in the middle thereof.
[0071] FIG. 2 illustrates a conceptual configuration of the PM
shown in FIG. 1.
[0072] Referring to FIG. 2, the PM 2, which is configured as an
etching process unit for performing an etching process on the
semiconductor wafer W, includes a cylindrical chamber 10 made of
metal, e.g., aluminum or stainless steel. In the chamber 10 is
placed a columnar susceptor 11 serving as a stage for the
semiconductor wafer W whose diameter is, e.g., 300 mm, to be
mounted on.
[0073] Between the chamber 10 and the susceptor 11 is formed a gas
exhaust path 12 used for exhausting gas from a space above the
susceptor 11 to the outside of the chamber. In the middle of the
gas exhaust path 12 is located an annular baffle plate 13, and a
part of the gas exhaust path 12 below the baffle plate 13
communicates with an adaptive pressure control valve (hereinafter,
referred to as "APC") 14 which is a variable butterfly valve. The
APC (Adaptive Pressure Control Valve) 14 is connected to a turbo
molecular pump (hereinafter, referred to as "TMP") 15 which is a
gas exhaust pump used for vacuum pumping, and, via the TMP 15, also
connected to a dry pump (hereinafter, referred to as "DP") 16,
which is also a gas exhaust pump. A main pumping line, i.e., a gas
exhaust path including the APC 14, the TMP 15 and the DP (Dry Pump)
16, controls a pressure in the chamber 10 by using the APC 14 and
depressurizes the inside of the chamber 10 by using the TMP 15 and
the DP 16.
[0074] Further, the part of the gas exhaust path 12 below the
baffle plate 13 is connected to another pumping line (hereinafter,
referred to as "rough pumping line"). The rough pumping line
includes a gas exhaust pipe 17, whose diameter is, e.g., 25 mm, for
making said part of the gas exhaust path 12 communicate with the DP
16 and a valve V2 installed in the middle thereof. The valve V2 can
isolate the DP 16 from said part of the gas exhaust path 12. The
rough pumping line exhausts gas in the chamber by using the DP
16.
[0075] The susceptor 11 is connected to a high frequency power
supply 18 via a matching unit 19, and the high frequency power
supply 18 applies a specified high frequency power to the susceptor
11. Thus, the susceptor 11 functions as a lower electrode. Further,
the matching unit 19 reduces a reflection of the high frequency
power at the susceptor 11 to maximize a supply efficiency of the
high frequency power to the susceptor.
[0076] In an upper part of the inside of the susceptor 11 is
installed an electrode plate 20 having a shape of a circular plate
shape made of a conductive layer for elecrostatically adsorbing the
wafer W. The electrode plate 20 is electrically connected to a DC
power supply 22. The wafer W is maintained to be adsorbed on an
upper surface of the susceptor 11 by a Johnsen-Rahbek force or a
Coulomb force generated by a DC voltage applied to the electrode
plate 20 by the DC power supply 22. Further, on the susceptor 11 is
placed a ring-shaped focus ring 24 made of, e.g., silicon (Si) or
the like. The focus ring 24 concentrates plasma generated above the
susceptor 11 onto the wafer W.
[0077] In the susceptor 11 is installed an annular coolant chamber
25 extending, for example, in a circumferential direction. Coolant
such as cooling water kept at a specified temperature is provided
to the coolant chamber 25 from a chiller unit (not shown) via a
distribution pipe 26, so that the processing temperature of the
wafer W on the susceptor 11 is adjusted by the temperature of the
coolant.
[0078] On a part of the upper surface of the susceptor 11 on which
the wafer W is adsorbed (hereinafter, referred to as "adsorption
surface") are a plurality of heat transfer gas supply openings 27
and heat transfer gas supply grooves (not shown). The heat transfer
gas supply openings 27 and the heat transfer gas supply grooves are
connected to a heat transfer gas supply unit 29 via the heat
transfer gas supply line 28 arranged in the susceptor 11. The heat
transfer gas supply unit 29 supplies a heat transfer gas such as He
gas to a space between the adsorption surface and a backside of the
wafer W. Further, the heat transfer gas supply unit 29 is
configured such that the space between the adsorption surface and
the backside of the wafer W can also be vacuum pumped.
[0079] Furthermore, on the adsorption surface is disposed a
plurality of pusher pins 30 which are lift pins that can be freely
moved up and down in the upper surface of the susceptor 11. The
pusher pins 30 can be moved in a vertical direction by converting a
motion of a motor (not shown) from a rotational one into a
reciprocating linear one by using a ball screw or the like. While
the wafer W is maintained to be adsorbed on the adsorption surface,
the pusher pins 30 are pulled down to be accommodated within the
susceptor 11. However, while the wafer W is being taken out from
the chamber 10 after a plasma processing is completed, the pusher
pins 30 become protruded from the upper surface of the susceptor 11
to lift and separate the wafer W from the susceptor 11.
[0080] On a ceiling portion of the chamber 10 is installed a shower
head 33. The shower head 33, being earthed, functions as a grounded
electrode.
[0081] The shower head 33 includes an electrode plate 35 having a
plurality of gas air openings on its lower surface and an electrode
supporting member 36 for supporting the electrode plate 35 such
that it can be attached thereto and separated therefrom. Further,
in the electrode supporting member 36 is placed a buffer chamber
37, which is connected to a processing gas inlet line 38 extended
from a processing gas supply unit (not shown). In the middle of the
processing gas inlet line 38 is installed an MFC (Mass Flow
Controller) 39. The MFC 39 supplies a specified gas, e.g., a
processing gas or an N.sub.2 gas, to the chamber 10 via the buffer
chamber 37 and controls a flow rate of the supplied gas to keep the
pressure in the chamber 10 at a desired level with the help of the
APC. Herein, a distance D between the susceptor 11 and the shower
head 33 is set to be, e. g., 35.+-.1 mm or more.
[0082] On a side wall of the chamber 10 is attached the gate valve
5 for opening and closing a loading/unloading port 31 for loading
and unloading the wafer W. In the chamber 10 in the PM 2, as
described above, a high frequency power is applied to the susceptor
11, and, by applying the high frequency power, a plasma is
generated from the processing gas in a space S between the
susceptor 11 and the shower head 33 to produce ions and
radicals.
[0083] When the etching process is performed in the PM 2, at first,
the gate valve 5 is opened and the wafer W as an object to be
processed is transferred into the chamber 10 to be mounted on the
susceptor 11. Thereafter, the processing gas, for example, a
gaseous mixture of C.sub.4F.sub.8, O.sub.2 and Ar gas having a
specified flow rate ratio, is supplied through the shower head 33
at a specified flow rate and flow rate ratio into the chamber 10,
and the pressure in the chamber 10 is kept at a specified level by
using the APC 14 and the like. Further, the high frequency power is
applied to the susceptor 11 from the high frequency power supply 18
and the DC voltage is applied to the electrode plate 20 from the DC
power supply 22 such that the wafer W is adsorbed onto the
susceptor 11. Then, the processing gas supplied through the shower
head 33 becomes a plasma as described above. The radicals and the
ions generated from the plasma are concentrated onto the surface of
the wafer W by the action of focus ring 24, and the surface of the
wafer W is etched physically or chemically.
[0084] Referring back to FIG. 1 again, the atmospheric transfer
unit 3 includes a wafer cassette mounting platform 41 for mounting
the wafer cassette 40 and a loader module 42 (hereinafter, referred
to as "LM").
[0085] The wafer cassette mounting platform 41 has a shape of a
platform whose upper surface is flat, and the wafer cassette 40
accommodates, e.g., 25 wafers W by mounting them at multiple levels
with an equal pitch. Further, the LM 42, having a shape of a
rectangular parallelepiped box, includes therein a Scara type
transfer arm 43 for transferring the wafers W.
[0086] Furthermore, on a side wall of the LM 42 adjacent to the
wafer cassette mounting platform 41 is a shutter (not shown)
confronting the wafer cassette 40 mounted on the wafer cassette
mounting platform 41. The shutter allows the wafer cassette 40 to
communicate with the inside of the LM 42.
[0087] The transfer arm 43 includes a multi-joint arm unit 44 that
can be bent, expandable and contractible and a pick 45 attached at
a front end of the arm unit 44. The pick 45 is configured such that
the wafer W can be mounted thereon directly. Further, the transfer
arm 43 further includes a multi-joint mapping arm 46 that can be
flexible and at a front end thereof installed a mapping sensor (not
shown) for detecting the wafer W by, for example, emitting a laser
beam. Base ends of the arm unit 44 and the mapping arm 46 are
connected to an elevation unit 49 for moving up and down along an
arm base supporting column 48 standing on the base portion 47 in
the transfer arm 43. In addition, the arm base supporting column 48
is configured to be revolvable. During a mapping operation for
detecting the number and positions of the wafers W accommodated in
the wafer cassette 40, the mapping arm 46, while being extended,
moves up or down to detect the number and positions of the wafers W
in the wafer cassette 40.
[0088] Since the transfer arm 43 can be bent by using the arm unit
44 and can be revolved by using the arm base supporting column 48,
the wafer W mounted on the pick 45 can be efficiently transferred
between the wafer cassette 40 and the LL 4.
[0089] The LL 4 includes a chamber 51 in which a transport arm 50
that is flexible and revolvable is installed; an N.sub.2 gas supply
system 52 for supplying an N.sub.2 gas into the chamber 51; and an
LL gas pumping system 53 for exhausting the inside of the chamber
51.
[0090] The transport arm 50 is a Scara type transfer arm containing
a plurality of arm units, and has a pick 54 attached at a front end
thereof. The pick 54 is configured such that the wafer W can be
mounted thereon directly.
[0091] In case the wafer W is transferred from the atmospheric
transfer unit 3 to the PM 2, the transport arm 50 takes the wafer W
from the transfer arm 43 in the LM 42 when the gate valve 6 is
opened, and, when the gate valve 5 is opened, the transport arm 50
is introduced into the chamber 10 in the PM 2 and the wafer W is
mounted on the pusher pins 30 protruded from the upper surface of
the susceptor 11. Further, in case the wafer W is transferred from
PM 2 to the atmospheric transfer unit 3, when the gate valve 5 is
opened, the transport arm 50 is introduced into the chamber 10 in
the PM 2 and takes the wafer W mounted on the pusher pins 30
protruded from the upper surface of the susceptor 11, and, when the
gate valve 6 is opened, the transport arm 50 transfers the wafer W
to the transfer arm 43 in the LM 42.
[0092] Furthermore, the transport arm 50 is not limited to a Scara
type, and a frog leg type or a double arm type arm may also be
employed as the transport arm 50.
[0093] The N.sub.2 gas supply system 52 includes an N.sub.2 gas
inlet line 55 passing through from the outside to the inside of the
chamber 51; a control valve 56 installed in the middle of the
N.sub.2 gas inlet line 55; a couple of break filters 100 installed
at a front end of the N.sub.2 gas inlet line 55 in the chamber 51
for jetting the N.sub.2 gas; and an N.sub.2 gas supply device (not
shown) connected to the other front end of the N.sub.2 gas inlet
line 55 outside of the chamber 51. The N.sub.2 gas supply system 52
supplies the N.sub.2 gas to the chamber 51 at a predetermined
timing, and adjusts the pressure in the chamber 51.
[0094] Each of the break filters 100 is of a mesh shape having a
length of, e.g., 200 mm, and made of metal. It can increase a
jetting area of the N.sub.2 gas to reduce a flow rate of the jetted
N.sub.2 gas, thereby uniformly raising the pressure in the chamber
51 by jetting the N2 gas uniformly onto a large area.
[0095] In an LL in the conventional substrate processing system, a
length of a break filter is, e.g., 100 mm, and a jetting area of
N.sub.2 gas is small, so that the N.sub.2 gas is jetted from the
break filter at a high flow rate, causing particles in the chamber
51 to be swirled up. To avoid this problem, in the conventional LL,
an SSV (Slow Start Valve) is installed in the middle of an N.sub.2
gas inlet line for the SSV to reduce the flow rate of the N.sub.2
gas.
[0096] On the contrary, in the LL 4 of the substrate processing
system in accordance with the preferred embodiment of the present
invention, the flow rate of the N2 gas is reduced by using the
break filters 100, so that the particles can be prevented from
being swirled up without an SSV. Further, since the jetting area of
the N.sub.2 gas is set to be large, the N.sub.2 gas of desired
volume can be quickly supplied into the chamber 51, thereby
enhancing the throughput.
[0097] The LL gas pumping system 53, including a gas exhaust pipe
57 penetrating into the inside of the chamber 51 and a control
valve 58 installed in the middle of the gas exhaust pipe 57,
adjusts the pressure in the chamber 51 with the help of the N.sub.2
gas supply system 52.
[0098] The operation of every element of the PM 2, the atmospheric
transfer unit 3 and the LL 4 in the substrate processing system 1
is controlled by a computer (not shown) functioning as a control
device contained in the substrate processing system 1 or an
external server (not shown) functioning as a control device
connected to the substrate processing system 1, pursuant to a
program for performing the substrate processing method in
accordance with the preferred embodiment of the present
invention.
[0099] Although the susceptor 11 as a lower electrode is not
configured to be moved with respect to the chamber 10 in the PM
connected to the LL 4 in the substrate processing system 1, the PM
connected to the LL 4 is not limited thereto, and, for example, it
is also possible to configure the PM such that a lower electrode
thereof can be moved with respect to a chamber thereof.
[0100] FIG. 3 is a cross sectional view depicting a conceptual
configuration of another PM that can be connected to the LL in the
substrate processing system shown in FIG. 1.
[0101] Referring FIG. 3, the PM 60, which is configured as an
etching process unit for performing an etching process on the
semiconductor wafer W, includes a cylindrical chamber 61 made of,
e.g., aluminum; a supporting body 64 capable of moving up and down,
located in the chamber 61 for supporting a lower electrode 62 on
which a semiconductor wafer W whose diameter is, e.g., 200 mm is
mounted via an insulator 63; and a shower head 65 as an upper
electrode confronting the lower electrode 62 at an upper portion in
the chamber 61.
[0102] In upper portion of the chamber 61 is formed a
small-diameter upper room 66, and in lower portion of the chamber
61 is formed a large-diameter lower room 67. Around the upper room
66 is installed a dipole ring magnet 68, which generates a uniform
horizontal magnetic field of a single direction. An upper portion
of a side wall of the lower room 67 is attached the gate valve 5
for opening and closing the loading/unloading port of the wafer W.
The PM 60 is connected to the LL 4 via the gate valve 5.
[0103] The lower electrode 62 is connected to a high frequency
power supply 69 via a matching unit, and the high frequency power
supply 69 applies a specified high frequency power to the lower
electrode 62. Thus, the lower electrode 62 functions as a lower
electrode.
[0104] An upper surface of the lower electrode 62 is placed an
electrostatic chuck (ESC) 71 for electrostatically adsorbing the
wafer W thereon. In the electrostatic chuck 71 is located an
electrode plate 72 of a circular plate shape made of a conductive
layer, which is electrically connected to a DC power supply 73. The
wafer W is kept to be adsorbed on the upper surface of the
electrostatic chuck 71 by a Coulomb force or the like generated by
a DC voltage applied to the electrode plate from the DC power
supply 73. Around the electrostatic chuck 71 is placed a focus ring
74, which concentrates plasma generated above the lower electrode
62 onto the wafer W.
[0105] Between the side wall of the upper room and the lower
electrode is formed a gas exhaust path for exhausting gas above the
lower electrode 62 to the outside of the chamber 61. In the middle
of the gas exhaust path is located an annular evacuation plate
(partitioning plate) 75. A part of the gas exhaust path below the
evacuation plate 75, i.e., an inner space of the lower room 67,
communicates with a pumping system 76 including a main pumping line
having an APC, a TPM and a DP and a rough pumping line which serves
as a bypass between the inner space of the lower room 67 and the
DP. The pumping system 76 not only performs a pressure control but
also a depressurization of the inside of the chamber 61 to the
vacuum level.
[0106] Below the lower electrode 62 is placed a lower electrode
elevation unit having a ball screw 77 installed such that it is
downwardly extended from the supporting body 64. The lower
electrode elevation unit supports the lower electrode 62 via the
supporting body 64, and moves up and down the lower electrode 62 as
a GAP by rotating the ball screw 77 by using a motor (not shown) or
the like. The lower electrode elevation unit is isolated from the
atmosphere in the chamber 61 by a bellows 78 around the lower
electrode elevation unit and a bellows cover 79 around the bellows
78.
[0107] Further, on the lower electrode 62 is installed a plurality
of pusher pins 80 that can be protruded from the upper surface of
the electrostatic chuck 71. The pusher pins 80 moves up and down in
a manner same as the pusher pins 30 shown in FIG. 1.
[0108] In the PM 60, when the wafer W is transferred by the
transport arm 50, the lower electrode 62 moves down to a
transferring position of the wafer W and the pusher pins 80 become
protruded from the upper surface of the electrostatic chuck 71 to
move up the wafer W to be separated from the lower electrode.
Further, when an etching process is performed on the wafer W, the
lower electrode 62 moves up to a processing position of the wafer W
and the pusher pins 80 remain buried in the lower electrode 62, so
that the electrostatic chuck 71 maintains the wafer W adsorbed
thereon.
[0109] Furthermore, inside the lower electrode 62 is located, e.g.,
an annular coolant chamber 81 extended in a circumferential
direction. To the coolant chamber 81 is supplied coolant, e.g.,
cooling water, kept at a specified temperature from a chiller unit
(not shown) via a distribution pipe, and the temperature at which
the wafer W on the lower electrode 62 is processed is adjusted by
the temperature of the coolant.
[0110] On the upper surface of the electrostatic chuck 71 is placed
a plurality of heat transfer gas supply openings and heat transfer
gas supply grooves (not shown). The heat transfer gas supply
openings and grooves are connected to a heat transfer gas supply
unit 84 via a heat transfer gas supply line 83 installed in the
lower electrode, and the heat transfer gas supply unit 84 supplies
the heat transfer gas, e.g., He gas, into a space between the
electrostatic chuck 71 and wafer W. The heat transfer gas supply
unit 84 is configured such that the space between the electrostatic
chuck 71 and the wafer W can be vacuum pumped.
[0111] The shower head installed on a ceiling portion of the
chamber 61 is earthed and functions as a grounded electrode.
Further, above the upper surface of the shower head is located a
buffer chamber 85, which is connected to a processing gas inlet
line 86 extended from a processing gas supply unit (not shown). In
the middle of the processing gas inlet line 86 is installed an MFC
87. The MFC 87 supplies a specified gas, e.g., the processing gas
or the N.sub.2 gas, into the chamber 61 via the buffer chamber 85
and the shower head 65, and controls the flow rate of the supplied
gas to adjust the pressure in the chamber 61 with the help of the
APC.
[0112] In the chamber in the PM 60, as described above, the high
frequency power is applied to the lower electrode 62, and a high
density plasma is generated from the processing gas between the
lower electrode 62 and the shower head 65 by the applied high
frequency power to generate ions and radicals.
[0113] When the etching process is performed in the PM 60, at
first, the gate valve 5 is opened and the wafer W as an object to
be processed is transferred into the chamber 61. Thereafter, the
processing gas, for example, a gaseous mixture of C.sub.4F.sub.8,
O.sub.2 and Ar gas having a specified flow rate ratio, is supplied
through the shower head 65 at a specified flow rate, flow rate
ratio into the chamber 61, and the pressure in the chamber 61 is
set to be kept at a specified level by using the APC and the like.
Further, the high frequency power is applied to the lower electrode
62 from the high frequency power supply 69 and the DC voltage is
applied to the electrode plate 72 from the DC power supply 73 such
that the wafer W is adsorbed onto the lower electrode 62. Then, the
processing gas supplied through the shower head 65 is converted
into a plasma as described above. The radicals and the ions
generated from the plasma are concentrated onto the surface of the
wafer W by the focus ring 74, and the surface of the wafer W is
etched physically or chemically.
[0114] In the following, a substrate processing method in
accordance with a preferred embodiment will be described. This
substrate processing method is performed in the substrate
processing system 1.
[0115] FIG. 4 provides a flow chart describing a wafer processing
in accordance with the substrate processing method of the preferred
embodiment. Hereinafter, the process will be described as to a case
where the LL 4 is connected to the PM 2 in the substrate processing
system 1.
[0116] In FIG. 4, at first, the transfer arm 43 in the atmospheric
transfer unit 3 and the transport arm 50 in the LL4 transfer a
dummy wafer from the wafer cassette 40 to the chamber 10 in the PM,
and the PM performs a dummy processing for arranging a processing
environment in the chamber 10 by using the dummy wafer (step
S41).
[0117] Thereafter, a control unit connected to the substrate
processing system 1 sets a counter n to be "1" (step S42). Next,
the transfer arm 43 in the atmospheric transfer unit 3 and the
transport arm 50 in the LL 4 transfer the wafer W which is not yet
processed into the chamber 10 in the PM 2 from the wafer cassette
40 (step S43). Then, the PM 2 performs a step-0 operation for
setting the pressure in the chamber 10 to be at a level of an
adsorption pressure of the wafer W before the etching process
(hereinafter, referred to as "process pressure") by using the APC
14 and the MFC 39 (step S44).
[0118] When the pressure in the chamber 10 reaches the process
pressure, the PM 2 performs a step-1 operation for keeping the
wafer W adsorbed on the upper surface of the susceptor 11 by using
the electrode plate 20 and supplying the He gas into the space
between the adsorption surface of the susceptor 11 and the backside
of the wafer W by using the heat transfer gas supply unit 29 (step
S45).
[0119] Thereafter, the PM 2 performs a step-2 operation for
generating ions and radicals by generating a high density plasma
from the processing gas in the space S by using the high frequency
power applied to the susceptor 11 and performing the etching
process on the wafer W by using the ions and the like (step
S46).
[0120] Subsequently, the PM 2 vacuum pumps to perform a backside
exhaustion for removing He gas by exhausting the heat transfer
supply openings 27 and the heat transfer supply line 28 to prevent
the wafer W from bouncing during the subsequent dechucking (step
S47). Then, the wafer dechucking is performed for removing
electrostatic charges on the wafer W by applying a reverse voltage
to the electrode plate 20 or the plasma to the wafer W, as will be
described in the following.
[0121] Next, the transfer arm 43 in the atmospheric transfer unit 3
and the transport arm 50 in the LL 4 take out the wafer on which
the etching process is performed from the chamber 10 to transfer
the wafer W into the wafer cassette 40 (step S49).
[0122] Thereafter, the control unit detects whether the value of
the counter n is greater than a predetermined value N representing
a predetermined number of wafers to be processed (step S50). If the
value of n is equal to or smaller than the predetermined value N,
the process is returned to the step S43; otherwise, the process is
completed.
[0123] In this wafer processing process, each of the steps S43 and
S49 (substrate transfer steps) and the steps S44 and S48 (substrate
processing steps) includes a plurality of operations. For example,
the step S43 includes a gate valve opening operation for opening
the gate valve 5; a pusher pin protruding operation for protruding
the pusher pins 30 from the upper surface of the susceptor 11; a
transport arm moving operation for moving the transport arm 50 into
the chamber 10; a purging operation for opening the APC completely;
and an N.sub.2 gas cutting-off operation for stopping to supply the
N.sub.2 gas into the chamber 10 by the MFC 39.
[0124] Whereas a plurality of operations included in each step are
sequentially carried out in the conventional substrate processing
method, at least two operations among the plurality of operations
included in the steps shown in FIG. 4 are performed simultaneously
in the substrate processing method in accordance with the preferred
embodiment. For example, in the step S43, the purging operation,
the N.sub.2 gas cutting-off operation and the pusher pin protruding
operation are performed simultaneously.
[0125] Further, a wafer processing process performed in case the LL
4 is connected to the PM 60 in the substrate processing system 1 is
same as that shown in FIG. 4.
[0126] In accordance with the substrate processing method of the
preferred embodiment, at least two operations among the plurality
of operations included in the steps shown in FIG. 4 are carried out
simultaneously. Therefore, while a specified device in the PM 2,
the atmospheric transfer unit 3 or the LL 4 performs a specified
operation, other devices not involved in the specified operation
performs their own operations, thereby reducing the time needed for
the etching process on the wafer W and greatly enhancing the
throughput.
[0127] Further, by using the substrate processing apparatus in
accordance with the preferred embodiment, at least two devices in
the PM 2, the atmospheric transfer unit 3 or the LL are operated
simultaneously in at least one step among the steps shown in FIG.
4, thereby reducing the time needed for the etching process on the
wafer W to enhance the throughput greatly.
[0128] In the following, there will be given an explanation on
specified examples of the substrate processing method in.
accordance with the preferred embodiment in case the LL 4 is
connected to the PM 2 in the substrate processing system 1.
Further, in FIG. 5 and the drawings thereafter, solid lines are
related to the substrate processing method in accordance with the
preferred embodiment and dotted lines are related to the
conventional substrate processing method.
[0129] FIG. 5 represents a sequence chart describing a first
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of transferring the wafer
W into the chamber 10 shown in FIG. 4.
[0130] In the conventional method, when the wafer W is transferred
into the chamber 10, at first, the heat transfer gas supply unit
vacuum pumps the heat transfer gas supply line (VACUUM). After the
vacuum pumping is completed (OFF), the transport arm is extended
into the chamber 10 (EXTEND) to mount the wafer W onto the upper
ends of the pusher pins, and the transport arm is retracted to
withdraw from the chamber 10 (RETRACT). However, the substrate
processing method in accordance with the preferred embodiment, the
heat transfer gas supply unit 29 starts to vacuum pump the heat
transfer gas supply line 28, and, at the same time, the transport
arm 50 is extended into the chamber 10 and retracted out of the
chamber 10 right after the vacuum pumping is completed.
[0131] Thus, the vacuum pumping of the heat transfer gas supply
line 28 and the transfer of the wafer W are performed
simultaneously, thereby greatly enhancing the throughput.
[0132] Further, in the conventional PM, since a vibration occurs by
inertial force when the transport arm stops, a delay time is
required between an operation of stopping transport arm and the
next operation, e.g., an operation of receiving the wafer W.
However, in the PM 2 in accordance with the preferred embodiment,
it is possible to abolish the delay time by optimizing the gain of
the movement control of the transport arm 50 in the PM 2. Thus, the
throughput can be further enhanced greatly.
[0133] FIGS. 6A to 6D and FIG. 7A present sequence charts
describing a second example of the substrate processing method in
accordance with the preferred embodiment, applied to the step of
transferring the wafer W into the chamber 10 shown in FIG. 4.
[0134] In the conventional method, the pusher pins have two setting
positions. One is an accommodated position (DOWN) corresponding to
a case where the pusher pins are accommodated inside of the
susceptor, and the other is a wafer receiving position (UP)
corresponding to a case where the pusher pins receives the wafer W
from the transport arm. In the substrate processing method in
accordance with the preferred embodiment, the pusher pins has
another position, i.e., a waiting position (WAIT) corresponding to
a case where the pusher arms wait for the transport arm 50 to come
into the chamber 10.
[0135] Further, in the conventional substrate processing method,
when the wafer W is transferred into the chamber 10, the pusher
pins become protruded to reach the receiving position after the
transport arm stops to be extended. However, in the substrate
processing method in accordance with the preferred embodiment, the
pusher pins 30 at the accommodated position (as shown in FIG. 6A)
become protruded to reach the waiting position (as shown in FIG.
6B) when the transport arm 50 starts to be extended to enter the
chamber 10. Then, the pusher pins do not move until the wafer W
mounted on the pick 54 is transferred to a position above the
susceptor 11 (as shown in FIG. 6C). After the transport arm 50
stops to be extended, the pusher pins 30 become further protruded
to reach the receiving position to receive the wafer W (as shown in
FIG. 6D).
[0136] Thus, the pusher pins 30 are protruded at the same time when
the wafer W is transferred into the chamber 10, thereby enhancing
the throughput greatly.
[0137] Further, since the pusher pins 30 are preferably raised by a
shorter distance, i.e., from the waiting position to the receiving
position, after the transport arm 50 stops to be extended, an
operation of receiving the wafer W can be completed in a shorter
time, thereby further enhancing the throughput significantly.
[0138] In addition, whereas the elevating speed of the pusher pins
in the conventional PM is 15 mm/sec, that of the pusher pins 30 in
the PM 2 is set to be 25 mm/sec, thereby enhancing the throughput
remarkably.
[0139] FIG. 7B is a sequence chart for representing a first example
of the substrate processing method in accordance with the preferred
embodiment, applied to the step of taking the wafer W out of the
chamber 10 shown in FIG. 4.
[0140] In the conventional substrate processing method, when the
wafer W is transferred out of the chamber, the pusher pins move
down from the receiving position to the accommodated position after
the transport arm is retracted to withdraw from the chamber 10.
However, in accordance with the substrate processing method in
accordance with the preferred embodiment, the pusher pins 30 at the
accommodated position become protruded to reach the receiving
position to mount the wafer W and then stop to move. After the
transport arm 50 stops to be extended, the pusher pins 30 move down
to the waiting position. Subsequently, when the transport arm 50
taking the wafer W starts to withdraw from the chamber 10, the
pusher pins 30 move down to the accommodated position again.
[0141] Thus, the pusher pins 30 move down at the same time when the
wafer W is transferred out of the chamber 10, thereby enhancing the
throughput greatly.
[0142] FIG. 8 shows a sequence chart for illustrating a third
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of taking the wafer W
into the chamber 10 shown in FIG. 4.
[0143] In the conventional substrate processing method, when the
wafer W is transferred into the chamber 10, the gate valve, which
has kept the loading/unloading port closed (CLOSE), is opened
(OPEN). Then, after the transport arm, which already transferred
the wafer W, withdraws from the chamber, the APC is completely
opened to switch from an OPEN mode for purging the inside of the
chamber to an ESC dechucking-pressure mode for maintaining the
pressure in the chamber at an ESC dechucking-pressure, i.e., a
pressure for neutralizing the susceptor. However, in the substrate
processing method in accordance with the preferred embodiment, the
gate valve 5 which has kept the loading/unloading port 31 closed is
opened, and, when the transport arm 50 on which the wafer W is
mounted starts to be introduced into the chamber 10, the APC 14 is
switched from the OPEN mode to the ESC dechucking-pressure
mode.
[0144] Thus, the wafer W is transferred into the chamber at the
same time when the APC is switched from the OPEN mode to the ESC
dechucking-pressure mode, thereby enhancing the throughput
remarkably.
[0145] FIG. 9 illustrates a sequence chart for illustrating a
fourth example of the substrate processing method in accordance
with the preferred embodiment, applied to the step of transferring
the wafer W into the chamber 10 shown in FIG. 4.
[0146] In the conventional substrate processing method, when the
wafer W is transferred into the chamber, a DC power supply HV is
switched from a HV reverse applied voltage mode for applying a
reverse voltage to the electrode plate for dechucking of the
susceptor to a non-applied voltage mode (designated by "0") for not
applying the voltage to the electrode plate, and further, the APC
is switched from the ESC dechucking-pressure mode to the OPEN mode
and the main pumping line of the PM starts to be vacuum pumped.
Subsequently, after a specified time, e.g., 10 seconds, elapses
from the time of the switching from the HV reverse applied voltage
mode to the non-applied voltage mode, the MFC is switched from a
maximum supply mode (designated by "max flow rate") for supplying
the inside of the chamber with the N.sub.2 gas at a maximum flow
rate to a non-supply mode (designated by "0") for not supplying gas
into the chamber. Thereafter, the APC is switched from the OPEN
mode to a STEP0 pressure mode for rapidly increasing the pressure
in the chamber to the process pressure, and the vacuum pumping of
the main pumping line in the PM is completed. Further, the gate
valve closes the loading/unloading port before the MFC is switched
to the non-supply mode.
[0147] However, in the substrate processing method in accordance
with the preferred embodiment, the pressure in the chamber 10 is
monitored after the loading/unloading port is closed by the gate
valve 5, and, if the monitored pressure is lower than a specified
pressure, the MFC 39 is switched from the maximum supply mode to
the non-supply mode. Thereafter, the APC 14 is switched from the
OPEN mode to the STEP0 pressure mode, and the vacuum pumping of the
main pumping line and the like in the PM 2 is completed.
[0148] Thus, since the vacuum pumping of the main pumping line and
the like in the PM 2 is performed based on the pressure in the
chamber 10, the throughput can be enhanced without further
performing the vacuum pumping excessively.
[0149] FIG. 10 presents a sequence chart for depicting a first
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of vacuum pumping the
backside shown in FIG. 4.
[0150] Conventionally, when vacuum pumping the rear side of the
semiconductor wafer W, the high frequency power supply RF is
switched from a high frequency power supply mode (ON) for supplying
the susceptor with a high frequency power to a non-supply mode
(OFF) for not supplying the susceptor with the high frequency
power. Meanwhile, the MFC is switched from a predetermined
processing gas flow rate mode (PREDETERMINED FLOW RATE of PRO GAS)
for supplying the processing gas into the chamber at a
predetermined flow rate to keep the inside of the chamber to be at
the process pressure to a non-supply mode, and then, the MFC is
switched from a non-supply mode to a predetermined N.sub.2 gas flow
rate mode (PREDETERMINED FLOW RATE of N.sub.2 GAS) for supplying
the N.sub.2 gas into the chamber at a predetermined flow rate to
perform the N.sub.2 gas purge in the chamber. Further, the heat
transfer gas supply unit vacuum pumps the heat transfer gas supply
line.
[0151] However, in the substrate processing method in accordance
with the preferred embodiment, the high frequency power supply 18
is switched from the high frequency supply mode to the non-supply
mode, and the MFC 39 is switched from the predetermined processing
gas flow rate mode to the non-supply mode. Meanwhile, the heat
transfer gas supply unit 29 vacuum pumps the heat transfer gas
supply line 28, and, thereafter, the MFC 39 is switched to the
predetermined N.sub.2 gas flow rate mode.
[0152] Thus, the transition from the high frequency power supply
mode to the non-supply mode of the high frequency power supply 18,
the transition from the predetermined processing gas flow rate mode
to the non-supply mode of the MFC 39 and the vacuum pumping of the
heat transfer gas supply line 28 in the heat transfer gas supply
unit 29 can be performed simultaneously, thereby markedly enhancing
the throughput.
[0153] FIG. 11 provides a sequence chart for describing a fifth
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of taking the wafer into
the chamber shown in FIG. 4.
[0154] Conventionally, in case of transferring the wafer into the
chamber, firstly the DC power supply is switched from the HV
reverse applied voltage mode to the non-applied voltage mode, and
the pusher pins are protruded from the accommodated position to the
receiving position. Thereafter, the APC is switched from the ESC
dechucking-pressure mode to the OPEN mode, and at the same time,
the MFC is switched from the predetermined N.sub.2 gas flow rate
mode to the non-supply mode. After a specified time has elapsed,
the MFC is switched to the predetermined N.sub.2 gas flow rate mode
again.
[0155] However, in the substrate processing method in accordance
with the preferred embodiment, when the DC power supply 22 is
switched from the HV reverse applied voltage mode to the
non-applied voltage mode, the pusher pins 30 are moved up from the
accommodated position to a first waiting position (designated by
"ESC position-0.5 mm" in FIG. 11) which is lower than the surface
of the susceptor 11 by about 0.5 mm. After a specified time has
elapsed, the pusher pins 30 starts to be moved up from the first
waiting position to a second waiting position (designated by "ESC
position +0.5 mm" in FIG. 11) which is higher than the surface of
the susceptor 11 by about 0.5 mm, and then the APC 14 is switched
from the ESC dechucking-pressure mode to the OPEN mode, and the MFC
39 is switched from the predetermined N.sub.2 gas flow rate mode to
the non-supply mode.
[0156] Thus, the elevation of the pusher pins 30, the transition
from the ESC dechucking-pressure mode to the OPEN mode of the APC
14 and the transition from the predetermined N.sub.2 gas flow rate
mode to the non-supply mode of the MFC 39 are performed
simultaneously, thereby markedly enhancing the throughput.
[0157] FIG. 12 is a sequence chart for showing a first example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the STEP0 shown in FIG. 4.
[0158] Conventionally, in case the pressure in the chamber is
changed to the process pressure, firstly the loading/unloading port
is closed by the gate valve, and the MFC is switched from the
maximum supply mode to the non-supply mode. Thereafter, the MFC is
switched from the non-supply mode to the predetermined processing
gas flow rate mode, and, at the same time, the APC is witched from
the OPEN mode to the STEP0 pressure mode. After a specified time
has elapsed, the DC power supply is switched from the non-applied
voltage mode to the HV application mode for applying the DC voltage
to the electrode plate.
[0159] However, in the substrate processing method in accordance
with the preferred embodiment, after the MFC 39 is switched from
the maximum supply mode to the non-supply mode, then the MFC 39 is
switched from the non-supply mode to the predetermined processing
gas flow rate mode. Meanwhile, if a target pressure of the STEP0
pressure mode is set to be equal to or lower than the process
pressure, i.e., the predetermined pressure at a STEP1, the APC 14
is switched from the OPEN mode to the process pressure mode for
maintaining the pressure in the chamber to be at the process
pressure. On the other hand, if the target pressure of the STEP0
pressure mode is higher than the process pressure, the APC 14 is
switched from the OPEN mode to the STEP0 pressure mode, and, after
a specified time has elapsed, the APC 14 is switched from the STEP0
mode to the process pressure mode.
[0160] Thus, the APC 14 selects a preferable mode based on the
target pressure at the STEP0 pressure mode, thereby markedly
enhancing the throughput without further increasing the
pressure.
[0161] FIG. 13 illustrates a sequence chart for explaining a sixth
example of the substrate processing method in accordance with the
preferred embodiment, applied to the step of taking the wafer into
the chamber shown in FIG. 4.
[0162] Conventionally, in case of transferring the wafer W into the
chamber, firstly the APC is switched from the OPEN mode to ESC
dechucking-pressure mode before the wafer W is transferred into the
chamber. Thereafter, the DC power supply unit is switched from the
non-applied voltage mode to the HV reverse applied voltage mode and
then the HV reverse applied voltage mode to the non-applied voltage
mode, thereby making the susceptor charge-neutralized. After the
wafer W as an object to be processed is transferred into the
chamber, the gate valve closes the loading/unloading port, and then
the APC is switched from the ESC dechucking-pressure mode to the
OPEN mode. In this case, since the time needed for the transition
from the ESC dechucking-pressure mode to the OPEN mode of the APC
is longer than the time needed for the gate valve to be closed, the
transition to the OPEN mode of the APC continues for a while even
after the gate valve is closed.
[0163] However, in the substrate processing method in accordance
with the preferred embodiment, right after the DC power supply 22
is switched from the HV reverse applied voltage mode to the
non-applied voltage mode, the APC 14 is switched from the ESC
dechucking-pressure mode to the OPEN mode. After the transition to
the OPEN mode of the APC is completed, the gate valve 5 closes the
loading/unloading port 31.
[0164] Thus, the transition to the OPEN mode of APC 14 does not
continue any more after the gate valve 5 is closed, thereby
significantly enhancing the throughput.
[0165] FIG. 14 is a sequence chart for showing an example of a case
where the wafer W is transferred between the LL and the atmospheric
transfer unit.
[0166] In the conventional substrate processing system, in case the
wafer W is transferred between the LL and the atmospheric transfer
unit, firstly the N.sub.2 gas supply unit supplies the N.sub.2 gas
into the chamber in the LL at a predetermined flow rate, and, after
a PSW (Pressure SWitch) in the LL is switched from OFF to ON and
then to an atmospheric atmosphere mode, the valve of the
communication pipe is opened to let it communicate with the LM.
After a specified time has elapsed from the PSW being switched to
ON, the gate valve is opened.
[0167] However, in the substrate processing method in accordance
with the preferred embodiment, after a PSW (not shown) in the LL 4
is switched from OFF to ON and then to the atmospheric atmosphere
mode, the valve of the communication pipe is opened to let it
communicate with the LM. When the transfer arm 43 is moved to a
front of the gate valve 6 after the PSW being switched to ON, the
gate valve is opened.
[0168] Thus, the transfer arm 43 need not wait in front of the gate
valve 6 after the transfer arm 43 is moved to the front of the gate
valve 6, thereby markedly enhancing the throughput.
[0169] FIG. 15 is a sequence chart for showing a second example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the step of taking the wafer out of
the chamber shown in FIG. 4.
[0170] Conventionally, in case of taking the wafer w out of the
chamber, before the APC is switched from the ESC
dechucking-pressure mode to the OPEN mode, the rough pumping line
starts to exhaust the inside of the chamber. Then, if the pressure
in the chamber is decreased to, e.g., 133 Pa (100 Torr), the APC is
switched to the OPEN mode, and the main pumping line starts to
exhaust the inside of the chamber.
[0171] However, in the substrate processing method in accordance
with the preferred embodiment, when the pressure in the chamber is
decreased to, e.g., 666 Pa (500 Torr) after the rough pumping line
starts to exhaust the inside of the chamber, the APC 14 is switched
to the OPEN mode, and the main pumping line starts to exhaust the
inside of the chamber.
[0172] Thus, the main pumping starts to exhaust the inside of the
chamber earlier than the conventional case, thereby noticeably
enhancing the throughput.
[0173] Further, in the conventional atmospheric transfer unit,
after the transfer arm 43 is moved down and the number and
positions of the wafers W in the wafer cassette 40 are detected by
using the extended mapping arm to detect, the elevation unit 49 is
moved up along the arm base supporting column. When the elevation
unit 49 reaches the upper end of the arm base supporting column 48,
the mapping arm 46 is contracted.
[0174] However, in the substrate processing method in accordance
with the preferred embodiment, the mapping arm 46 is contracted as
soon as the elevation unit 49 starts to be moved up along the arm
base supporting column 48.
[0175] Thus, the elevation of the elevation unit 49 and the
contraction of the mapping arm 46 are performed simultaneously,
thereby markedly enhancing the throughput.
[0176] FIG. 16 is a sequence chart for showing a first example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the STEP2 shown in FIG. 4.
[0177] Conventionally, before performing the etching process on the
wafer W, the DC power supply is switched from the non-applied
voltage mode to the HV reverse applied voltage mode, and then the
high frequency power supply is switched from the non-supply mode to
the high frequency power supply. mode. Further, after performing
the etching process on the wafer W, the high frequency power supply
is switched from the high frequency power supply mode to the
non-supply mode, and then the DC power supply is switched from the
HV reverse applied voltage mode to the non-applied voltage
mode.
[0178] However, in the substrate processing method in accordance
with the preferred embodiment, the wafer W is supplied with
electric charges by using plasma and thus the electrostatic
adsorptive force between the wafer W and susceptor 11 is
intensified to thereby reduce a depressurization level of the
pressure in the chamber 10 required for electrostatically adsorbing
the wafer W onto the susceptor 11 and decrease the time for the HV
reverse application. Further, to promote the dechucking of the
wafer W, the electric charges on the wafer W are removed by using
the plasma. That is, in the substrate processing method in
accordance with the preferred embodiment, the high frequency power
supply mode of the high frequency power supply 18 is performed for
a longer period compared to the conventional substrate processing
method.
[0179] Specifically, before performing the etching process on the
wafer W, the high frequency power supply 18 is switched from the
non-supply mode to the high frequency power supply mode, and then
the DC power supply 22 is switched from the non-applied voltage
mode to the HV reverse applied voltage mode. Further, after
performing the etching process on the wafer W, the DC power supply
is switched from the HV application mode to the non-applied voltage
mode, and then the high frequency power supply is switched from the
high frequency power supply mode to the non-supply mode.
[0180] Thus, the depressurization level of the pressure in the
chamber 10 required for electrostatically adsorbing the wafer W
onto the susceptor 11 is reduced, and the dechucking of the wafer W
is promoted, thereby greatly enhancing the throughput.
[0181] Further, in the heat transfer gas supply unit in the
conventional PM, the heat transfer gas supply openings respectively
confronting a central portion and a peripheral potion of the rear
side of the wafer W mounted on the upper surface of the susceptor
are connected to the DP via a distribution pipe having a single
valve and another distribution pipe having another valve and an
orifice, respectively. The heat transfer gas supply unit has the
rear side of the wafer W vacuum pumped by opening the valve in one
of the two distribution pipes to make the heat transfer gas supply
openings communicate with the DP.
[0182] However, as shown in FIG. 17, in the heat transfer supply
unit 29 in the PM 2 in the substrate processing system in
accordance with the preferred embodiment, the heat transfer gas
supply openings 27 respectively confronting a center portion and a
peripheral portion (respectively designated by "CENTER" and "EDGE"
in FIG. 17) of the rear side of the wafer W mounted on the upper
surface of the susceptor 11 are connected to a PCV (Pressure
Control Valve) (not shown) via a valve V65 and a valve V66,
respectively.
[0183] Further, the heat transfer gas supply openings 27
respectively confronting the center portion and the peripheral
portion are connected to the DP 16 via first distribution pipes
101a and 101b having valves V67 and V68 and second distribution
pipes 102a and 102b having orifices and valves V45 and V46,
respectively, and connected to the distribution pipe 105 between
the chamber 10 and the APC 14 via third distribution pipes 103a and
103b, respectively. Therefore, the heat transfer gas supply
openings 27 respectively confronting a center portion and a
peripheral portion of the rear side of the wafer W are connected to
the TMP 15 via the third distribution pipes 103a and 103b and the
APC 14.
[0184] Thus, the rear side of the wafer W can be vacuum pumped by
the TMP 15, and the vacuum pumping of the rear side of the wafer W
and the heat transfer gas supply line 28 can be performed quickly,
thereby greatly enhancing the throughput.
[0185] FIG. 18 shows a sequence chart for illustrating a valve
control of the heat transfer gas supply unit shown in FIG. 17.
[0186] After the etching process is performed on the wafer W at
STEP2 shown in FIG. 4, the valves V45, V46, V65 and V66 opened at
STEP2 are kept opened. Thus, the He gas is provided to the rear
side of the wafer W via the PVC, and a surplus amount of He gas is
removed from the heat transfer supply line 28 by using the DP
16.
[0187] Thereafter, at the step of vacuum pumping the rear side
shown in FIG. 4, firstly the valve V67 and V68 are opened to remove
the He gas in the heat transfer gas supply line 28 by using the DP
16. After a specified time has elapsed, the valves V61 and V62 are
opened, and then the valves V67 and V68 are closed to remove the He
gas in the heat transfer gas supply line 28 by using the TMP 15.
Subsequently, the valves V61 and V62 are closed, and then the
valves V45, V46, V65 and V66 are also closed.
[0188] When the valve V61 and V62 are opened, the end portions of
the third distribution pipes 103a and 103b communicate with the
inside of the chamber 10, so that, if the pressure of the He gas
remaining in the heat transfer gas supply line 28 is high, the
remaining He gas may be introduced into the chamber 10 to thereby
prevent the inside of the chamber 10 from being lowered. To counter
this, in the sequence shown in FIG. 18, the He gas in the heat
transfer gas supply line 28 is removed by using the DP 16 before
the He gas is removed by using the TMP 15 to lower the pressure of
the He gas in the heat transfer gas supply line 28, thereby
preventing the He gas from being introduced into the chamber 10
when the valves V61 and V62 are opened.
[0189] FIG. 19 provides a sequence chart for depicting a second
example of the substrate processing method in accordance with the
preferred embodiment, being applied to STEP2 shown in FIG. 4.
[0190] Conventionally, in case the etching process is performed on
the wafer W, the high frequency power supply is repeatedly switched
between the high frequency power supply mode and the non-supply
mode. However, the substrate processing method in accordance with
the preferred embodiment, the high frequency power supply 18 is
repeatedly switched between the high frequency power supply mode
and a high frequency power reduction mode for steadily reducing the
high frequency power supplied to the susceptor.
[0191] Thus, during a time interval between an operation of STEP2
and a next repeated operation of the STEP2, a significant amount of
the plasma is left on the susceptor 11. Thus, a desired amount of
the plasma can be generated more quickly during the next repeated
operation of the STEP2, thereby markedly enhancing the
throughput.
[0192] FIG. 20 provides a sequence chart for depicting a first
example of the substrate processing method in accordance with the
preferred embodiment, which is applied to the STEP1 shown in FIG.
4.
[0193] Conventionally, when electrostatically adsorbing the wafer
W, the DC power supply is switched from the non-applied voltage
mode to the HV application mode after the MFC is switched from the
non-supply mode to the predetermined processing gas flow rate mode.
Herein, as the supplying flow rate of the processing gas in the
predetermined processing gas flow rate mode, a sufficient amount of
the flow rate is set to increase the pressure in the chamber to
make it easy to discharge the surplus amount of electric charges
charged on the adsorption surface of the susceptor and to adsorb
the wafer W onto the susceptor. Further, the DC power supply is
switched to the HV application mode to electrostatically adsorb the
wafer W when the pressure difference between the upper and the
backside of the wafer W becomes sufficient for adsorbing the
wafer.
[0194] In the substrate processing method in accordance with the
preferred embodiment, similarly to the conventional substrate
processing method, after the MFC 39 is switched from the non-supply
mode to the predetermined processing gas flow rate mode, the DC
power supply 22 is switched from the non-applied voltage mode to
the HV application mode. However, the supplying flow rate of the
processing gas in the predetermined processing gas flow rate mode
of the MFC 39 is set to be greater than that of the conventional
substrate processing method, e.g., equal to the supplying flow rate
of the N.sub.2 gas in the maximum supply mode.
[0195] Thus, the pressure in the chamber quickly reaches a pressure
level at which the surplus amount of the electric charges on the
adsorption surface of the susceptor can be discharged, and the DC
power supply 22 is switched to the HV application mode earlier,
thereby greatly enhancing the throughput.
[0196] FIG. 21 is a sequence chart for showing a second example of
the substrate processing method in accordance with the preferred
embodiment, which is applied to the STEP1 shown in FIG. 4.
[0197] Conventionally, in case of supplying the He gas to the
backside of the wafer W, when a specified stabilization time, e.g.,
2 seconds has elapsed after the DC power supply is switched from
the non-applied voltage mode to the HV application mode, the heat
transfer gas supply unit supplies the He gas to the backside of the
wafer W via the heat transfer supply line. However, in he substrate
processing method in accordance with the preferred embodiment, the
stabilization time is reduced to, e.g., 0.5 second.
[0198] Thus, the He gas is supplied to the backside of the wafer W
earlier, thereby greatly enhancing the throughput.
[0199] FIG. 22 depicts a sequence chart for representing a second
example of the substrate processing method in accordance with the
preferred embodiment, which is applied to the step of the vacuum
pumping of the backside shown in FIG. 4.
[0200] Conventionally, when increasing the pressure in the chamber
to the ESC dechucking-pressure, an opening degree (angle) of the
variable valve in the APC is adjusted by, e.g., a feedback control
to control the pressure in the chamber. Herein, the APC is
automatically controlled (AUTO) so that the angle of the variable
valve is changed until the pressure in the chamber is stabilized,
but the fine adjustment of the angle of the variable valve is
difficult to be made. Thus, the pressure in the chamber repeatedly
swings between an overshoot state and an undershoot state.
[0201] However, in the substrate processing method in accordance
with the preferred embodiment, when controlling the pressure in the
chamber 10, the APC is automatically controlled so that the angle
of the variable valve is changed if the pressure in the chamber 10
is lower than a specified level. Thereafter, if the pressure in the
chamber 10 is increased to become higher than the specified level,
the automatic control of the APC is cancelled so that the angle of
the variable valve becomes fixed (SET ANGLE). Then, the pressure in
the chamber 10 is controlled by a supplying amount of the
processing gas of the MFC 39.
[0202] Thus, if the pressure in the chamber 10 is higher than the
specified level, the angle of the variable valve in the APC is
fixed, so that the swing between the overshoot and undershoot state
of the pressure in the chamber 10 can be avoided and the pressure
in the chamber 10 is quickly stabilized at a desired level, thereby
greatly enhancing the throughput.
[0203] Further, in the conventional PM, when controlling the
pressure in the chamber by using the APC or the MFC, a threshold
value of pressure change to activate an interlock which is a mode
of stopping device operations is set in a manner independent of the
chamber pressure control steps shown in FIG. 4. However, in the
substrate processing method in accordance with the preferred
embodiment, the threshold value of pressure change is set in a
manner that it varies depending on the respective steps shown in
FIG. 4. Specifically, the threshold value of pressure change is set
to be small at the STEP1 and STEP2, whereas the threshold value of
pressure change is set to be large at other steps, wherein a small
change in the pressure in the chamber is allowable, such as the
steps of taking the wafer into the chamber, vacuum pumping the
backside and the wafer dechucking.
[0204] Thus, unnecessary activations of the interlocks can be
reduced at the steps of taking the wafer into the chamber, vacuum
pumping the backside and the wafer dechucking, thereby remarkably
enhancing the throughput.
[0205] FIG. 23 presents a sequence chart for providing a seventh
example of the substrate processing method applied to the step of
taking the wafer into the chamber and a third example of the step
of taking the wafer out of the chamber shown in FIG. 4 in
accordance with the preferred embodiment.
[0206] Conventionally, when the pusher pins are protruded, the
pusher pins at the accommodated position are firstly moved up to
the first waiting position lower than the surface of the susceptor
by 0.5 mm, and, after waiting a specified time, the pusher pins are
moved up to the second waiting position higher than the surface of
the susceptor by 0.5 mm. Then, after waiting another specified
time, the pusher pins are moved up to the receiving position.
Further, when the pusher pins are moved down, a reverse sequence of
the sequence described above is followed.
[0207] However, in the substrate processing method in accordance
with the preferred embodiment, the waiting positions of the pusher
pins 30 are omitted. Specifically, when the pusher pins 30 at the
accommodated position start to be protruded, they move directly up
to the receiving position. Further, when the pusher pins 30 at the
receiving position start to be moved down, they move directly down
to the accommodated position.
[0208] Thus, the waiting time of the pusher pins 30 during moving
up and down can be omitted, thereby remarkably enhancing the
throughput.
[0209] Conventionally, in a wafer replacement process, since the
N.sub.2 gas in the chamber in the LL is introduced into the chamber
in the PM due to a pressure difference between the chamber in the
LL and the chamber in the PM while the gate valve is opened, the
APC is maintained at the OPEN mode for the inside of the chamber to
be purged except for the time when the dechucking of the susceptor
is performed. Therefore, the processing gas cannot be introduced
into the chamber by the MFC while the gate valve is opened, so that
it is difficult for the pressure in the chamber to quickly reach
the process pressure by supplying the processing gas.
[0210] However, in the wafer replacement process in accordance with
the preferred embodiment, the operations of the N.sub.2 gas supply
system 52 in the LL 4 and the LL gas exhaust unit 53 are controlled
based on the pressure difference between the chamber 51 in the LL 4
and the chamber 10 in the PM 2, and this pressure difference is
made to disappear before the gate valve 5 is opened. Thus, the N2
gas in the chamber 51 in the LL 4 is prevented from being
introduced into the chamber 10 in the PM 2, so that the pressure in
the chamber can be quickly changed to the process chamber by
supplying the processing gas.
[0211] FIG. 24 represents a flow chart of the wafer replacement
process in accordance with the preferred embodiment.
[0212] Referring to FIG. 24, the pressure difference between the
chamber 51 in the LL 4 and the chamber 10 in the PM 2 is made to
disappear by controlling the operations of the N.sub.2 gas supply
system 52 and the LL gas exhaust system 53 (step S242), and the
transport arm 50 takes the wafer W out of the chamber 10 (step
S243).
[0213] Thereafter, the APC 14 is switched from the OPEN mode to the
ESC dechucking-pressure mode, the MFC 39 is switched from the
non-supply mode to the maximum supply mode, and the DC power supply
22 is switched from the non-applied voltage mode to the HV reverse
applied voltage mode, thereby performing the dechucking of the
susceptor 11, i.e., the ESC dechucking (step S244).
[0214] Thereafter, the MFC 39 is switched from the maximum supply
mode to the predetermined processing gas flow rate mode, and, at
the same time, the APC 14 is switched from the ESC dechucking mode
to the OPEN mode (step S245). After a specified time has elapsed,
the APC 14 is switched from the OPEN mode to the process pressure
mode to thereby make the pressure inside the chamber 10 be set at
the process pressure (step S246).
[0215] Subsequently, the transport arm 50 takes a next wafer W into
the chamber 10 (step S247), and the gate valve 5 is closed (step
S248) to complete this process.
[0216] In accordance with the process shown in FIG. 24, since the
pressure difference between the chamber 51 in the LL 4 and the
chamber 10 in the PM 2 is made to disappear before the gate valve 5
is opened, the N.sub.2 gas in the chamber 51 in the LL 4 is not
introduced into the chamber 10 in the PM 2.
[0217] Conventionally, as illustrated by dotted lines in FIG. 25,
even after the ESC dechucking, the APC needs to be maintained in
the OPEN mode for a long time to purge the N.sub.2 gas introduced
into the chamber in the LL, and the MFC needs to be maintained in
the maximum supply mode to enhance the efficiency of the purge.
However, in accordance with the process shown in FIG. 24, since the
N.sub.2 gas in the chamber 51 in the LL 4 is not introduced into
the chamber 10 in the PM 2, the APC need not be maintained in the
OPEN mode for a long time and the MFC need not be maintained in the
maximum supply mode after the ESC dechucking. Therefore, in the
process shown in FIG. 24, right after the ESC dechucking is
performed, the MFC 39 is switched from the maximum supply mode to
the predetermined processing gas flow rate mode, and, at the same
time, the APC 14 is switched from the ESC dechucking mode to the
OPEN mode. Further, the APC 14 is switched to the process pressure
mode, so that the pressure inside the chamber 10 quickly becomes
settled at the process pressure, as shown in FIG. 25. Thus, the
throughput can be enhanced greatly.
[0218] In the following, an example of the substrate processing
method in accordance with the preferred embodiment in case where
the LL 4 in the substrate processing system 1 is connected to the
PM 60. Further, in FIGS. 26A to 26C and the drawings thereafter,
the operations in the substrate processing method in accordance
with the preferred embodiment are represented by solid lines and
the operations in the conventional substrate processing method are
represented by dotted lines.
[0219] FIGS. 26A to 26C present sequence diagrams for illustrating
an eighth example of the substrate processing method applied to the
step of taking the wafer into the chamber and a fourth example of
the step of taking the wafer out of the chamber shown in FIG. 4 in
accordance with the preferred embodiment.
[0220] Conventionally, when the wafer w is transferred into the
chamber, the pusher pins become protruded from the upper surface of
the electrostatic chuck on the lower electrode (GAP) at the
loading/unloading position to move up to the receiving position for
receiving the wafer W. The pusher pins having received the wafer W
is moved down to the accommodated position, so that the wafer W is
mounted on the electrostatic chuck. The electrostatic chuck on
which the wafer W is mounted is moved up to the processing position
along with the lower electrode.
[0221] Further, when the wafer W is taken out of the chamber, the
electrostatic chuck on which the wafer W is mounted is moved down
to the loading/unloading position along with the lower electrode.
Thereafter, the pusher pins become protruded from the upper surface
of the electrostatic chuck to lift the wafer W on the electrostatic
chuck to the receiving position.
[0222] However, in the substrate processing method in accordance
with the preferred embodiment, when the wafer w is transferred into
the chamber 61, the pusher pins 80 become protruded from the upper
surface of the electrostatic chuck 71 on the lower electrode 62
(GAP) at the loading/unloading position to move up to the receiving
position for receiving the wafer W (see FIG. 26A). The pusher pins
80 having received the wafer W are kept at the receiving position
for the time being. Thereafter, the electrostatic chuck 71 starts
to be moved up along with the lower electrode 62. The electrostatic
chuck 71 receives the wafer W from the pusher pins 80 while it is
on the rise. Then, the electrostatic chuck 71 is moved up to the
processing position (see FIG. 26B).
[0223] Further, when the wafer W is taken out of the chamber 61,
the electrostatic chuck 71 on which the wafer W is mounted starts
to be moved down along with the lower electrode after the etching
process is performed on the wafer W. The electrostatic chuck 71
transfers the wafer W to the pusher pins 80 while it is moving
down. Then, the electrostatic chuck 71 is moved down to the
loading/unloading position (see FIG. 26C). After the pusher pins 80
deliver the wafer W to the transport arm 50, they move down to the
accommodated position.
[0224] Thus, when the wafer is transferred into the chamber 61, the
pusher pins 80 are not moved down from the receiving position to
the accommodated position, and further, when the wafer is
transferred out of the chamber 61, the pusher pins 80 are not moved
up from the accommodated position to the receiving position. Thus,
the wafer W can be transferred more quickly, thereby greatly
enhancing the throughput.
[0225] FIG. 27 provides a sequence chart for depicting a third
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the STEP1 shown in FIG.
4.
[0226] Conventionally, when the electrostatic chuck is moved up to
he processing position along with the lower electrode, firstly the
gate valve is closed and, at the same time, the pusher pins are
moved down from the receiving position to the accommodated
position. Thereafter, the APC is switched from the OPEN mode to the
process pressure mode, the DC power supply is switched from the
non-applied voltage mode to the HV application mode, and the
electrostatic chuck is moved up from the loading/unloading position
to the processing position along with the lower electrode.
[0227] However, in the substrate processing method in accordance
with the preferred embodiment, firstly the gate valve 5 is closed,
and then the pusher pins 80 are moved down from the receiving
position to the accommodated position, the APC is switched from the
OPEN mode to the process pressure mode, and the electrostatic chuck
71 is moved up from the loading/unloading position to the
processing position along with the lower electrode 62. Thereafter,
the DC power supply 73 is switched from the non-applied voltage
mode to the HV application mode.
[0228] Thus, the APC is switched from the OPEN mode to the process
pressure mode at the same time when the electrostatic chuck 71 is
moved up from the loading/unloading position to the processing
position, thereby substantially enhancing the throughput.
[0229] FIG. 28 is a sequence chart for showing a fifth example of
the substrate processing method in accordance with the preferred
embodiment, that is applied to the step of taking the wafer out of
the chamber shown in FIG. 4.
[0230] Conventionally, when the wafer W is taken out of the
chamber, firstly the heat transfer gas supply unit finishes the
vacuum pumping of the heat transfer gas supply line, and then the
electrostatic chuck is moved down from the processing position to
the loading/unloading position along with the lower electrode.
Thereafter, the APC is switched from the process pressure mode to
the OPEN mode.
[0231] However, in the substrate processing method in accordance
with the preferred embodiment, the lower electrode 62 further has a
middle position (MIDDLE) between the processing position and the
loading/unloading position. Thus, when the wafer W is taken out of
the chamber 62, firstly the heat transfer gas supply unit 84
finishes the vacuum pumping of the heat transfer gas supply line
83, and then the electrostatic chuck 71 is moved down from the
processing position to the middle position along with the lower
electrode 62. Then, after a specified time has elapsed, the
electrostatic chuck 71 is moved down from the middle position to
the loading/unloading position along with the lower electrode 62.
Meanwhile, the APC is switched from the process pressure mode to
the OPEN mode.
[0232] Thus, the electrostatic chuck 71 is moved down from the
middle position to the loading/unloading position at the same time
when the APC is switched from the process pressure mode to the OPEN
mode, thereby greatly enhancing the throughput.
[0233] FIG. 29 represents a sequence chart for describing a sixth
example of the substrate processing method in accordance with the
preferred embodiment, that is applied to the step of taking the
wafer out of the chamber shown in FIG. 4.
[0234] Conventionally, when the wafer W is taken out of the
chamber, firstly the pusher pins are moved up from the accommodated
position to the receiving position to lift the wafer W. Then, after
the gate valve is opened, the transport arm enters the chamber to
receive the wafer W, and then withdraws from the chamber.
[0235] However, in the substrate processing method in accordance
with the preferred embodiment, when the wafer W is taken out of the
chamber 61, firstly the pusher pins 80 are moved up from the
accommodated position to the receiving position to lift the wafer
W. Meanwhile, the gate valve 5 is opened. Thereafter, the transport
arm 50 enters the chamber 61 to receive the wafer W, and then
withdraws from the chamber 61.
[0236] Thus, the pusher pins 80 are moved up from the accommodated
position to the receiving position at the same time when the gate
valve 5 is opened, thereby markedly enhancing the throughput.
[0237] Further, the above-described examples may be applied to the
substrate processing system 1 individually or as a combination of
two or more of them.
[0238] Furthermore, a host computer or an external server connected
to the substrate processing system 1 monitors a maintenance period
of the devices in the substrate processing system 1 such as the PM
2, the atmospheric transfer unit 3 and the LL 4, and, if the
devices are in the maintenance period, the host computer or the
external server sends a maintenance command to a software in the
computer in the substrate processing system 1. The software, having
received the maintenance command, determines whether the PM 2, the
atmospheric transfer unit 3 or the LL 4 can be moved on to a
maintenance state. If the PM 2, the atmospheric transfer unit 3 or
the LL 4 is in an idle state so that it can be moved on to the
maintenance state, the software performs an atmospheric opening
sequence for increasing the pressure in the chamber 10 in the PM 2
or the pressure in the chamber 51 in the LL 4 to an atmospheric
level.
[0239] Thus, administrators and the like can start a maintenance
operation immediately, thereby enhancing the operating rate of the
substrate processing system 1.
[0240] Further, the object of the invention can also be achieved by
providing a memory medium (or a storage medium) storing a program
code of a software for implementing the functions of the preferred
embodiment to a substrate processing system 1 or the PM 2 so that
the control device in the substrate processing system 1 or the PM 2
such as a computer, a CPU or a MPU, or the control device connected
to the substrate processing system 1 such as an external server
reads out the program code stored in the memory medium to execute
it.
[0241] Still further, although the functions of the preferred
embodiment can be implemented in a manner that the computer or the
like reads out to perform the program code as described above, the
functions of the preferred embodiment can also be implemented in a
manner that an operating system (OS) or the like in the computer or
the like performs all or a part of processes for performing the
program code in response to a command of the program code, wherein
the functions of the preferred embodiment are implemented by the
processes for performing the program code.
[0242] Furthermore, the functions of the preferred embodiment can
also be implemented in a manner that the program code read out from
the memory medium is stored in a memory included in a function
extension card inserted in the computer or the external server or a
function extension unit connected to the external server, and, in
response to commands of the program code, a CPU or the like
included in the function extension card or the function extension
unit performs all or a part of the processes for performing the
program code, wherein the functions of the preferred embodiment are
implemented by the processes for performing the program code.
[0243] In addition, any program code will be satisfactory as long
as it makes it possible for the functions of the embodiment to be
implemented by the computer or the external server. The form of the
program code may be an object code, a program code performed by
using an interpreter, script data supplied to an OS, or so
forth.
[0244] As for the memory medium, any memory medium will be
satisfactory as long as it can store the program code, namely, a
RAM, a NV-RAM, a floppy disc, a hard disc, an optical disc, a
magneto-optical disc, a CD-ROM, a MO, a CD-R, a CD-RW, a DVD
(DVD-ROM, DVD-RAM, DVD-RW and DVD+RW), a magnetic tape, a
nonvolatile memory card and other kinds of ROM. Otherwise, the
program code can be downloaded from other computers, databases or
the like (not shown) connected to the Internet, a commercial
network or a local area network, the like.
[0245] Further, it is also possible to configure an optimal
substrate processing sequence in a manner that the host computer or
the external server connected to the substrate processing system 1
monitors the operations of the respective devices in the substrate
processing system 1 such as the PM 2, the atmospheric transfer unit
3 and the LL 4 or a processing situation of the wafer to extract
operations that can be performed simultaneously based on the
monitoring result and make a combination of the extracted
operations. In this case, the operations of the respective devices
of the substrate processing system 1 such as the PM 2, the
atmospheric transfer unit 3 and the LL 4 can be controlled by the
optimal substrate processing sequence. Thus, the throughput can be
enhanced effectively.
[0246] Still further, in case the substrate processing system 1
includes a plurality of PMs 2 and a plurality of wafers W are
sequentially processed by the plurality of PMs, the host computer
or the external server makes a list of a wafer process sequence for
defining the sequence of the processes to be performed on the
plurality of wafers W, and the substrate processing system 1
processes the respective wafers W based on the list of the wafer
process sequence. In addition, when a process on a wafer W listed
on the list is performed, the host computer or the external server
may monitor the operations of the respective devices in the
substrate processing system 1 such as the PM 2, the atmospheric
transfer unit 3 and the LL 4 or a processing situation of the wafer
and, based on the monitoring result, configure an optimal substrate
processing sequence with respect to the wafer W being currently
processed or another optimal substrate processing sequence with
respect to another wafer W to be processed next according to the
list. Thus, the throughput of the wafer W being currently processed
as well as the wafer W to be processed next according to the list
can be enhanced.
[0247] In the preferred embodiment described above, the explanation
has been given as to a case where the substrate processing
apparatus is an etching processing apparatus. However, the
substrate processing apparatus to which the present invention can
be applied is not limited thereto and may also be a coating and
developing apparatus, a substrate cleaning apparatus or an etching
apparatus.
[0248] Furthermore, although the explanation has been given as to a
case where the substrate to be transferred is a semiconductor wafer
in the preferred embodiment described above, the substrate to be
transferred is not limited thereto and may also be a glass
substrate of, e.g., a LCD (Liquid Crystal Display) or a FPD (Flat
Panel Display).
[0249] While the invention has been shown and described with
respect to the preferred embodiment, it will be understood by those
skilled in the art that various changes and modification may be
made without departing from the scope of the invention as defined
in the following claims.
* * * * *