U.S. patent application number 11/363046 was filed with the patent office on 2006-06-29 for substrate processing apparatus, method of controlling substrate, and exposure apparatus.
This patent application is currently assigned to CANON KABUSHIKI KAISHA. Invention is credited to Ryo Edo.
Application Number | 20060142890 11/363046 |
Document ID | / |
Family ID | 19060192 |
Filed Date | 2006-06-29 |
United States Patent
Application |
20060142890 |
Kind Code |
A1 |
Edo; Ryo |
June 29, 2006 |
Substrate processing apparatus, method of controlling substrate,
and exposure apparatus
Abstract
A load-lock apparatus including a load-lock chamber, a chuck,
arranged in the load-lock chamber, to hold a substrate, a pressure
reduction system to reduce a pressure in the load-lock chamber
using an exhaust valve, a pressure measurement system to measure a
pressure in the load-lock chamber, and a time measurement system to
measure an operating time of the pressure reduction system. The
exhaust valve is controlled such that a relationship between a
pressure measured by the pressure measurement system and a time
measured by the time measurement system falls within a
predetermined range with respect to a predetermined
relationship.
Inventors: |
Edo; Ryo; (Tochigi,
JP) |
Correspondence
Address: |
FITZPATRICK CELLA HARPER & SCINTO
30 ROCKEFELLER PLAZA
NEW YORK
NY
10112
US
|
Assignee: |
CANON KABUSHIKI KAISHA
Tokyo
JP
|
Family ID: |
19060192 |
Appl. No.: |
11/363046 |
Filed: |
February 28, 2006 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
10200782 |
Jul 24, 2002 |
7024266 |
|
|
11363046 |
Feb 28, 2006 |
|
|
|
Current U.S.
Class: |
700/112 |
Current CPC
Class: |
G03F 7/70808 20130101;
H01L 21/67103 20130101; G03F 7/7075 20130101; H01L 21/67248
20130101 |
Class at
Publication: |
700/112 |
International
Class: |
G06F 19/00 20060101
G06F019/00 |
Foreign Application Data
Date |
Code |
Application Number |
Jul 27, 2001 |
JP |
2001-227549 |
Claims
1-19. (canceled)
20. A load-lock apparatus comprising: a load-lock chamber; a chuck,
arranged in said load-lock chamber, to hold a substrate; a pressure
reduction system to reduce a pressure in said load-lock chamber
using an exhaust valve; a pressure measurement system to measure a
pressure in said load-lock chamber; and a time measurement system
to measure an operating time of said pressure reduction system,
wherein said exhaust valve is controlled such that a relationship
between a pressure measured by said pressure measurement system and
a time measured by said time measurement system falls within a
predetermined range with respect to a predetermined relationship.
Description
[0001] This application is a divisional application of copending
U.S. patent application Ser. No. 10/200,782, filed Jul. 24,
2002.
FIELD OF THE INVENTION
[0002] The present invention relates to a substrate processing
apparatus and a substrate control method and, for example, to a
substrate processing apparatus and a substrate processing method
suitable for a manufacturing process of a device such as a
semiconductor device or a liquid crystal display device.
BACKGROUND OF THE INVENTION
[0003] Along with an increase in the degree of integration of a
semiconductor device, a semiconductor integrated circuit has been
further micropatterned.
[0004] For example, considering a semiconductor exposure apparatus
which transfers a circuit pattern onto a silicon substrate, the
wavelength of exposure light used in exposure must be shortened for
micropatterning. The wavelength has been shortened from a g-line
and an i-line to a KrF laser beam, an ArF laser beam, an F.sub.2
laser beam, a soft X-ray radiated from an SR ring, or the like.
[0005] The exposure light with a short wavelength, such as the
F.sub.2 laser beam or soft X-ray is greatly attenuated in air.
Thus, the exposure unit of an exposure apparatus is stored in a
chamber, wherein an N.sub.2 atmosphere or a pressure-reduced He
atmosphere providing small attenuation of the exposure light is
formed, or a vacuum atmosphere is formed for an electron beam
exposure apparatus, and the like. In a substrate processing
apparatus, or the like, when process gas is different from the air
or when oxidation of a resist on the substrate is to be prevented,
an atmosphere different from the air or the vacuum atmosphere is
formed in a chamber.
[0006] Conventionally, as such a processing apparatus, an
arrangement shown in FIGS. 7 and 8 is known. The substrate
processing apparatus of this type includes a process chamber 1
serving as the first chamber which stores a process station for,
e.g., exposing the substrate in an atmosphere different from the
air, and a substrate supply portion 10 arranged in the air.
[0007] The substrate supply portion 10 includes a substrate carrier
support portion 101, on which a carrier 102 storing the substrate
is placed manually or by an automatic transfer apparatus.
[0008] In order to transfer a substrate to be processed between the
process chamber 1 and the substrate supply portion 10, a load-lock
chamber 3 serving as a second process chamber is arranged. A
plurality of load-lock chambers 3 may be arranged for
loading/unloading.
[0009] In the apparatus shown in FIGS. 7 and 8, the
pressure-reduced He atmosphere is formed in the process chamber 1,
which stores the processing unit.
[0010] The load-lock chamber 3 has a first gate valve 4 on the air
side to shield the load-lock chamber 3 from the substrate supply
portion 10 in the air, and a second gate valve 5 on the process
chamber 1 side to shield the load-lock chamber 3 from the process
chamber 1. The load-lock chamber 3 also has an exhaust mechanism 12
for exhausting gas from the load-lock chamber 3, an He gas supply
portion 13 for supplying He gas into the load-lock chamber 3, and
an N.sub.2 gas supply portion 14 for supplying N.sub.2 gas into the
load-lock chamber 3.
[0011] The load-lock chamber 3 includes a substrate holding chuck 6
designed to store, e.g., one or a plurality of substrates.
[0012] In the air, a first transfer mechanism 7 for transferring
the substrate between the substrate carrier 102 on the carrier
support portion 101 and the load-lock chamber 3 is arranged. In a
preliminary chamber 2, connected between the process chamber 1 and
the load-lock chamber 3, a second transfer mechanism 8 for
transferring the substrate between the load-lock chamber 3 and a
process station (exposure process portion) 20 is arranged.
[0013] The operation of the above conventional apparatus will be
described below.
[0014] The first transfer mechanism 7 extracts one substrate from
the substrate carrier 102 placed on the carrier support portion
101, and transfers the substrate to the load-lock chamber 3.
[0015] When the substrate is loaded into the load-lock chamber 3
and placed on the substrate holding chuck 6, the first gate valve
is closed to shield the load-lock chamber 3 from the air. The
atmosphere in the load-lock chamber 3 is purged.
[0016] Purging the atmosphere in the load-lock chamber 3 is
performed to be described below.
[0017] A vacuum exhaust valve 122 is opened in a state wherein the
load-lock chamber 3 is shielded from the air and the chamber 1 by
closing the first and second gate valves 4 and 5. The gas is then
exhausted from the load-lock chamber 3 by a vacuum exhaust pump
(not shown) via a vacuum exhaust pipe 121.
[0018] The chamber 3 is evacuated to a predetermined vacuum degree.
After evacuating the chamber 3 to the predetermined vacuum degree,
the vacuum exhaust valve 122 is closed, and the evacuation is
stopped.
[0019] The gas supply valve is then opened. The load-lock chamber 3
shown in FIG. 8 includes an He gas supply valve 132 and an N.sub.2
gas supply valve 142. At this stage, the He gas supply valve 132 of
these supply valves is opened to supply the same gas as the
atmosphere in the chamber 1 storing the process station (exposure
process portion) 20.
[0020] Until the pressure in the load-lock chamber 3 equals that in
the process chamber 1, the He gas is supplied. When the pressure in
the load-lock chamber 3 equals that in the process chamber 1, the
He gas supply valve 132 is closed to stop supplying the He gas.
[0021] When supply of the He gas is stopped, the second gate valve
5 is opened. The substrate on the substrate holding chuck 6 is
extracted by the second transfer mechanism 8 in the preliminary
chamber 2, and transferred to the process station (exposure process
portion) 20 in the process chamber 1.
[0022] The substrate processed in the process station (exposure
process portion) 20 is returned to the substrate carrier 102 via
the load-lock chamber 3 by the first and second transfer mechanisms
7 and 8.
[0023] During evacuation of the load-lock chamber 3 in the
above-apparatus, adiabatic expansion occurs in the load-lock
chamber 3, and the gas in the load-lock chamber 3 is cooled.
[0024] At this time, since the substrate and the substrate holding
chuck 6 in the load-lock chamber 3 are exposed to the gas in the
load-lock chamber 3, their temperatures are reduced along with
cooling the gas. The substrate cooling by the adiabatic expansion
in the load-lock chamber 3 is loaded into the process chamber 1 and
processed at the end of purging the atmosphere.
[0025] In the exposure apparatus, the substrate temperature needs
to be controlled with high precision in order to obtain high
transfer precision, the high line-width precision, and the like.
However, in the conventional apparatus, the temperature of the
substrate loaded into the process chamber 1 via the load-lock
chamber 3 is reduced, as described above. Hence, the transfer
precision deteriorates when exposure is performed for the wafer in
this state, thus posing a problem.
[0026] As a prior art arrangement related to the problem as
described above, an example is available, in which, in order to
control the substrate to a predetermined temperature, the substrate
is brought into contact with ambient gas and a substrate transfer
means to gradually increase the substrate temperature to the
predetermined temperature.
[0027] Such a method requires a long period of time for the
substrate to reach the predetermined temperature. This makes it
difficult to improve the throughput. Specifically, in the apparatus
in which the chamber is evacuated, since heat exchange is not
performed with the ambient gas, thermoregulation by the ambient gas
is not expected.
[0028] Hence, in this case, the substrate is thermally regulated
only by contact with the substrate transfer means. This requires a
longer period of time for the substrate to reach the predetermined
temperature.
SUMMARY OF THE INVENTION
[0029] The present invention has been made in consideration of the
above problem, and has as its object to provide a substrate
processing apparatus which prevents a decrease in throughput due to
a decrease in temperature of a substrate along with a reduction in
pressure in a load-lock chamber, a substrate controlling method,
and an exposure apparatus.
[0030] The first aspect of the present invention is related to a
substrate processing apparatus. The substrate processing apparatus
comprises a first chamber, a second chamber, which has a first
valve and a second valve, and communicates with the first chamber
through said second valve, a thermoregulator which regulates a
temperature of the substrate arranged in the second chamber, and a
controller which controls a time for which the thermoregulator
regulates the temperature of the substrate. In this apparatus, a
substrate transferred to the second chamber through the first valve
is temporarily held in the second chamber, and then transferred to
the first chamber through the second valve.
[0031] According to a preferred embodiment of the present
invention, the thermoregulator heats the substrate.
[0032] According to another preferred embodiment of the present
invention, the apparatus further comprises a pressure reduction
section which reduces a pressure in the second chamber, and the
pressure reduction section makes a relationship between the
pressure in the second chamber and a pressure reduction time for
which the pressure in the second chamber is reduced fall within a
predetermined range.
[0033] According to still another preferred embodiment of the
present invention, the apparatus further comprises a gas supply
portion which supplies a predetermined gas into the second
chamber.
[0034] According to still another preferred embodiment of the
present invention, the thermoregulator is arranged in a chuck for
holding the substrate, the chuck including an electrostatic
chuck.
[0035] According to still another preferred embodiment of the
present invention, the thermoregulator is arranged in a chuck for
holding the substrate, the chuck being controlled to have
substantially a constant power to chuck the substrate.
[0036] According to still another preferred embodiment of the
present invention, the thermoregulator is arranged in a chuck, and
the apparatus further comprises a driving section which separates
the substrate from the chuck.
[0037] According to still another preferred embodiment of the
present invention, the controller controls the driving section so
as to make a time for which the substrate is held by the chuck
constant.
[0038] According to still another preferred embodiment of the
present invention, the thermoregulator regulates a temperature of
the chuck to be higher than a temperature at which the substrate is
to be processed in the first chamber.
[0039] According to still another preferred embodiment of the
present invention, the apparatus further comprises a transfer
section which transfers the substrate, the thermoregulator is
arranged in a chuck, and the controller controls the transfer
section so as to make a time for which the substrate is held by the
chuck constant.
[0040] The second aspect of the present invention is related to a
substrate processing method. The method includes the steps of
regulating a temperature of a substrate in a load-lock chamber,
controlling a time for which the temperature of the substrate is
regulated in the load-lock chamber, transferring the substrate from
the load-lock chamber to a process chamber, and processing the
substrate in the process chamber.
[0041] The third aspect of the present invention is related to a
device manufacturing method. The method comprises the steps of
installing, in a device manufacturing factory, manufacturing
apparatuses for performing various processes, including the
substrate processing apparatus according to the present invention,
and manufacturing a device by performing a plurality of processes
using the manufacturing apparatuses.
[0042] According to a preferred embodiment of the present
invention, the method further comprises the steps of connecting the
manufacturing apparatuses via a local area network, and
communicating information about at least one of the manufacturing
apparatuses between the local area network and an external network
outside the device manufacturing factory.
[0043] According to another preferred embodiment of the present
invention, the method further comprises the step of accessing a
database provided by a vendor or user of the substrate processing
apparatus via the external network, thereby obtaining maintenance
information of the exposure apparatus by data communication.
[0044] According to still another preferred embodiment of the
present invention, the method further comprises the step of
performing data communication between the device manufacturing
factory and another device manufacturing factory via the external
network, thereby performing production management.
[0045] The fourth aspect of the present invention is related to a
device manufacturing factory. The device manufacturing factory
comprises manufacturing apparatuses for performing various
processes, including the substrate processing apparatus according
to the present invention, a local area network for connecting the
manufacturing apparatuses, and a gateway for allowing access to the
local area network and an external network outside the device
manufacturing factory, wherein information about at least one of
the manufacturing apparatuses can be communicated between the local
area network and the external network.
[0046] The fifth aspect of the present invention is related to a
maintenance method of the substrate processing apparatus according
to the present invention and installed in the device manufacturing
factory. The method comprises the steps of making a vendor or user
of the substrate processing apparatus provide a maintenance
database connected to an external network outside the device
manufacturing factory, allowing access to the maintenance database
from the device manufacturing factory via the external network, and
transmitting maintenance information accumulated in the maintenance
database to the device manufacturing factory via the external
network.
[0047] According to a preferred embodiment of the present
invention, the above substrate processing apparatus preferably
further comprises a display, a network interface, and a computer
for executing network software, and maintenance information of the
substrate processing apparatus can be communicated via a computer
network.
[0048] Other features and advantages of the present invention will
be apparent from the following description taken in conjunction
with the accompanying drawings, in which like reference characters
designate the same or similar parts throughout the figures
thereof.
BRIEF DESCRIPTION OF THE DRAWINGS
[0049] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate embodiments of
the invention and, together with the description, serve to explain
the principles of the invention.
[0050] FIG. 1 is a plan view showing the arrangement of a substrate
processing apparatus according to a preferred embodiment of the
present invention;
[0051] FIG. 2 is an elevational view showing the arrangement of the
substrate processing apparatus according to the preferred
embodiment of the present invention;
[0052] FIGS. 3A and 3B are views for explaining an example of a
thermoregulator for a substrate according to the preferred
embodiment of the present invention;
[0053] FIGS. 4A and 4B are views for explaining another example of
a thermoregulator for a substrate according to the preferred
embodiment of the present invention;
[0054] FIGS. 5A and 5B are views for explaining still another
example of a thermoregulator for a substrate according to the
preferred embodiment of the present invention;
[0055] FIGS. 6A and 6B are graphs each showing a change in
temperature of a substrate;
[0056] FIG. 7 is a plan view for explaining a conventional
apparatus arrangement;
[0057] FIG. 8 is an elevational view for explaining the
conventional apparatus arrangement;
[0058] FIG. 9 is a view showing one example of an exposure
apparatus main body according to the preferred embodiment of the
present invention;
[0059] FIG. 10 is a view showing a semiconductor device production
system using the apparatus according to the preferred embodiment of
the present invention when viewed from a given angle;
[0060] FIG. 11 is a view showing a semiconductor device production
system using the apparatus according to the preferred embodiment of
the present invention when viewed from another given angle;
[0061] FIG. 12 is a view of a practical example of a user
interface;
[0062] FIG. 13 is a flow chart showing a semiconductor device
manufacturing process; and
[0063] FIG. 14 is a flow chart showing a wafer process.
DETAILED DESCRIPTION OF THE PREFERRED EMBODIMENTS
[0064] (Embodiment of A Substrate Processing Apparatus)
[0065] FIG. 1 is a plan view showing an arrangement of a substrate
processing apparatus according to a preferred embodiment of the
present invention, and FIG. 2 is an elevational view of the
apparatus.
[0066] The substrate processing apparatus according to this
embodiment comprises a process chamber 1 serving as the first
process chamber and a substrate supply portion 10 arranged in the
air. The process chamber 1 is arranged as an exposure apparatus
having an internal space in which an exposure process portion 20
for transferring a pattern to a substrate is arranged and a
pressure-reduced He atmosphere is maintained.
[0067] The substrate supply portion 10 has a substrate carrier
support portion 101, on which a substrate carrier 102 storing a
substrate (wafer) W is placed manually or by an automatic transfer
apparatus. A preliminary chamber 2, which contains a second
transfer mechanism 8, is connected to the process chamber 1.
[0068] In order to transfer the substrate (wafer) W serving as a
photosensitive substrate, a load-lock chamber 3 serving as the
second chamber is arranged between the process chamber 1 and the
substrate supply portion 10. The load-lock chamber 3 includes a
first gate valve 4 on the air side to shield the load-lock chamber
3 from the substrate supply portion 10 in the air (external
environment), and a second gate valve 5 on the chamber side to
shield the load-lock chamber 3 from the preliminary chamber 2.
[0069] The load-lock chamber 3 also includes a manometer 31 for
measuring a pressure in the load-lock chamber 3, an exhaust
mechanism 12 for exhausting gas from the load-lock chamber 3, and
gas supply portions for supplying gas to the load-lock chamber 3.
In this embodiment, an He gas supply portion 13 for supplying He
gas and an N.sub.2 gas supply portion 14 for supplying N.sub.2 gas
are arranged as one example of the gas supply portions.
[0070] The exhaust mechanism 12 has a vacuum exhaust pump (not
shown), a vacuum supply pipe 121 for connecting the vacuum exhaust
pump and the load-lock chamber 3, and a vacuum exhaust valve 122
for regulating the flow rate of gas flowing to the vacuum exhaust
pump through an exhaust port. The exhaust mechanism 12 also has a
flowmeter 123 for measuring the flow rate of gas flowing in the
vacuum exhaust tube 121.
[0071] The gas supply portions (He gas supply portion 13 and
N.sub.2 gas supply portion 14) have the same structure. For
example, the He gas supply portion 13 has a supply pipe 131 for
connecting the He gas supply portion 13 to the load-lock chamber 3,
a gas supply valve 13 for controlling supply of gas flowing in the
supply pipe 131, and a gas supply flowmeter 134 for measuring the
flow rate of gas flowing between the gas supply valve 132 and
load-lock chamber 3. Similarly, the N.sub.2 gas supply portion 14
has a supply pipe 141 for connecting the N.sub.2 gas supply portion
14 to the load-lock chamber 3, a gas supply valve 142 for
controlling supply of gas flowing in the supply pipe 141, and a gas
supply flowmeter 144 for measuring the flow rate of gas flowing
between the gas supply valve 142 and load-lock chamber 3.
[0072] Particles are removed by a filter 133 from the supply gas
supplied from the He gas supply portion 13 through the gas supply
valve 132 and gas supply flowmeter 134, and the cleaned gas is
supplied to the process chamber 1 through the load-lock chamber 3.
Similarly, particles are removed by a filter 143 from the supply
gas supplied from the N.sub.2 gas supply portion 14 through the gas
supply valve 142 and gas supply flowmeter 144, and the cleaned gas
is supplied to the process chamber 1 through the load-lock chamber
3.
[0073] The load-lock chamber 3 has a substrate holding chuck 6
designed, e.g., to store one or a plurality of substrates.
[0074] In this embodiment, the substrate holding a chuck 6 is an
electrostatic suction chuck with attracts a substrate by applying a
voltage from a power surface (not shown). The substrate holding
chuck 6 has a voltmeter (not shown) which indicates an applied
voltage.
[0075] FIGS. 3A and 3B are views showing the substrate holding
chuck 6 in this embodiment.
[0076] The substrate holding chuck 6 has an internal electrode 61
and a heating element 62 which forms a thermoregulator. As the
heating element 62, for example, a heater may be used.
[0077] The substrate holding chuck 6 has a temperature sensor (not
shown) which measures temperatures of the substrate holding chuck 6
and provides measurement results to the controller of the heating
element 62.
[0078] The substrate holding chuck 6 further has a driving section
which lifts the substrate (wafer) W. The driving section may be
formed by, e.g., three pins 63 shown in FIG. 3A, but the present
invention is not limited to this. The driving section may have an
arbitrary structure as far as it can lift the substrate (wafer)
W.
[0079] Preferably, the load-lock chamber 3, the first transfer
mechanism 7 for transferring a substrate, and the second transfer
mechanism 8 are arranged to transfer the substrates one by one. In
addition, in order to minimize an exhaustion time, the internal
volume of the load-lock chamber 3 is preferably set to a minimum
size.
[0080] A first transfer mechanism 7 for transferring the substrate
(wafer) W between the substrate carrier 102 on the substrate
carrier support portion 101 and the load-lock chamber 3 is arranged
in the air. The second transfer mechanism 8 for transferring the
substrate (wafer) W between the load-lock chamber 3 and process
station (exposure apparatus portion) 20 is arranged in the
preliminary chamber 2 connected between the process chamber 1 and
the load-lock chamber 3.
[0081] When the wafer W is to be transferred between the substrate
holding chuck 6 and the first and second transfer mechanisms 7 and
8, the three pins 63 lift the wafer W.
[0082] The substrate holding hand of the first or second transfer
mechanism 7 or 8 is inserted in a gap between the substrate holding
chuck 6 and the wafer W lifted by the three pins 63. The substrate
holding hand lifts the substrate (wafer) W to separate it from the
three pins 63 of the chuck 6. The first or second transfer
mechanism 7 or 8 transfers the substrate (wafer) W separated from
the three pins 63 of the chuck 6. Note that the first and second
transfer mechanisms 7 and 8 transfer the substrate (wafer) W in a
horizontal direction in this embodiment, but the present invention
is not limited to this. For example, the first and second transfer
mechanism 7 and 8 may transfer the substrate (wafer) W in an
arbitrary direction, e.g., a vertical direction.
[0083] The operation of the substrate (wafer) transfer in the
exposure apparatus according to the present invention will be
described next.
[0084] The arm of the first transfer mechanism 7 is inserted in the
substrate carrier 102 in the air, and a single substrate (wafer) W
is extracted by this arm. The first transfer mechanism 7 holds the
substrate (wafer) W while bending its arm. Meanwhile, the pressure
gauge 31 measures the state of the atmosphere in the load-lock
chamber 3.
[0085] Assume that the pressure of the load-lock chamber 3 measured
by the pressure gauge 31 at that time is the atmospheric pressure.
In this case, the first transfer mechanism 7 rotates its arm toward
the load-lock chamber 3, and after confirming the opening state of
the first gate valve 4, the first transfer mechanism 7 stretches
its arm toward the substrate (wafer) W to load it into the
load-lock chamber 3. The substrate (wafer) W is placed on the three
pins 63 of the substrate holding chuck 6.
[0086] After the first transfer mechanism 7 moves its arm backward
to separate it from the substrate (wafer) W, the three pins 63 of
the substrate holding chuck 6 move downward to attract and hold the
substrate (wafer) W by the substrate holding chuck 6.
[0087] The thermoregulator starts thermal regulation of the wafer W
from a timing when the wafer W is attracted and held by the
substrate holding chuck 6. A controller 30 manages the time from a
timing when the thermoregulator starts the thermal regulation to
the wafer W.
[0088] After the substrate (wafer) W is attracted and held by the
substrate holding chuck 6, the first gate valve 4 is closed, and
the air is purged with He. A time from when the substrate (wafer) W
is held by the substrate holding chuck 6 until the first evacuation
for atmosphere purging is started is a predetermined time.
[0089] To purge the atmosphere, the air is exhausted to a vacuum
first. Preferably, the vacuum exhaust pump (not shown) is always
operated. This always keeps in a vacuum region from the vacuum
exhaust pump to the vacuum exhaust valve 122. When the first gate
valve 4 is closed and the vacuum exhaust valve is opened,
evacuation is started.
[0090] In this embodiment, preferably, in, e.g., device assembly,
device maintenance, or a test process, an experiment is conducted
in advance to obtain a curve representing the relationship between
a pressure in the load-lock chamber 3 and a pressure reduction time
(vacuum suction time) for which a pressure in the load-lock chamber
3 is reduced by the vacuum exhaust pump (not shown), and the
experiment resultant is prepared as data.
[0091] In evacuating the load-lock chamber 3, the relationship
between a vacuum suction time and a pressure in the load-lock
chamber 3 has been monitored by the exhaust gas flowmeter 123 and
the pressure gauge 31 of the load-lock chamber 3. When the
relationship falls outside a predetermined range with respect to
the curve, the opening degree of the exhaust valve 122 is
controlled such that the relationship falls within the
predetermined range. The predetermined range is set to be narrower
than an allowable value in the curve representing the relationship
between a pressure and a vacuum suction time decided from the
adiabatic cooling of the substrate (wafer) W. The relationship
between a vacuum suction time and pressure is controlled such that
it does not exceed the allowable value of the curve representing
the relationship between the predetermined vacuum suction time and
pressure.
[0092] Alternatively, the relationship between a pressure in the
load-lock chamber 3 and a vacuum suction time can also be monitored
by using the pressure gauge 31 of the load-lock chamber 3 and the
elapse of time.
[0093] That is, even if the pressure of the load-lock chamber 3 is
not controlled by the vacuum exhaust valve 122, a vacuum suction
time and pressure are measured to obtain a curve representing the
relationship therebetween, and it is confirmed to fall (the curve
representing the relationship therebetween) within a predetermined
range, thereby omitting the control of the vacuum exhaust valve
122.
[0094] After evacuating the load-lock chamber 3 to reach the
measurement value of a pressure therein measured by the pressure
gauge 31 of the load-lock chamber 3 to a predetermined value, the
vacuum exhaust valve 122 is closed, and the operation of drawing to
a vacuum in the load-lock chamber 3 ends. When the pressure value
in the load-lock chamber 3 becomes the predetermined pressure
value, the evacuation ends. Consequently, a time from the start to
the end of the evacuation is constant every time.
[0095] With this operation, the relationship between a vacuum
suction time and pressure is made constant every time.
[0096] In the evacuation operation described above, gas in the
load-lock chamber 3 is cooled by adiabatic expansion, and the
substrate (wafer) W in contact with the cooled gas is similarly
cooled.
[0097] Since the apparatus and a clean room in which the apparatus
is installed are in a constant temperature environment, the
temperatures of the device and the plurality of substrates (wafers)
W before the evacuation operation are constant.
[0098] Since a final pressure and vacuum suction time after the
evacuation operation are respectively constant, a decrease in
temperature due to the adiabatic expansion of gas to be exhausted
is made constant.
[0099] The relationship between (i) a time in which the cooled gas
is in contact with the substrate (wafer) W and (ii) the
temperatures of the gas in that time, becomes constant, because the
relationship between the vacuum suction time and the pressure is
made constant.
[0100] Therefore, even when the substrate (wafer) W is cooled by
the adiabatic expansion of gas, the temperature of the cooled
substrate (wafer) W is uniformly controlled.
[0101] The gas supply valve is then opened. The load-lock chamber 3
in FIG. 2 has the He gas supply valve 132 and N.sub.2 gas supply
valve 142 serving as the gas supply valves. A gas supply valve
which is opened in this case is a gas supply valve for supplying
the same gas as the atmosphere in the process chamber 1, which is
the He gas supply valve 132.
[0102] The He gas supply portion 13 supplies He gas until a
pressure in the load-lock chamber 3 equals that in the process
chamber 1. When a pressure in the load-lock chamber 3 equals that
in the process chamber 1, the He gas supply valve 132 is closed,
and supply of the He gas is stopped.
[0103] The flow rate of the supply gas supplied from the He gas
supply portion 13 is measured by the gas supply flowmeter 134. The
gas supply flowmeter 134 is so controlled as to end a supply of gas
within a predetermined time.
[0104] The predetermined time is preferably decided in advance on
the basis of the relationship between a flow rate and the volume of
the load-lock chamber 3. The gas supply valves 132 and 142 may be
controlled on the basis of the measurement values of the gas supply
flowmeters 134 and 144 so as to end a supply of gas within a
predetermined time.
[0105] After stopping supply of the He gas, the second gate valve 5
is opened, and the second transfer mechanism 8 of the preliminary
chamber 2 extracts the substrate (wafer) W in the load-lock
charnber 3 to transfer it to the process station (exposure process
portion) 20.
[0106] At this time, the controller 30 controls a thermal
regulating time by the substrate holding chuck 6 so as to make
constant a time for which the substrate (wafer) W is held on a
holding portion (substrate holding chuck 6).
[0107] More specifically, in this embodiment, after the substrate
(wafer) W is held by the substrate holding chuck 6 for a
predetermined time, the controller 30 controls the three pins 63 of
the chuck to lift the substrate (wafer) W.
[0108] At the stage in which the three pins 63 lift the substrate
(wafer) W, the chuck 6 ends the thermal regulation to the substrate
(wafer) W. The second transfer mechanism 8 then receives the
substrate (wafer) W.
[0109] The chuck 6 is preferably an electrostatic chuck. This makes
a suction force for the substrate (wafer) W constant regardless of
the ambient pressure if an applied voltage to an internal electrode
is set to be constant.
[0110] In this case, an applied voltage to the internal electrode
is measured by a voltmeter (not shown) and kept constant.
[0111] By keeping the suction force constant, the contact thermal
resistance between the substrate holding chuck 6 and substrate
(wafer) W is made constant.
[0112] The chuck 6 is similarly cooled by the adiabatic expansion
of gas in the load-lock chamber 3, but the thermoregulator (heater)
can keep the temperatures of the substrate (wafer) W and substrate
holding chuck 6 constant on the basis of a measurement result from
the temperature sensor (not shown) formed in the chuck 6.
[0113] With this operation, heat given from the chuck 6 to the
substrate (wafer) W is made constant.
[0114] If the temperature of the chuck 6 is kept at an appropriate
temperature in advance, even when the substrate (wafer) W is
cooled, a decrease in temperature of the substrate (wafer) W can be
recovered by heating the chuck 6 to a temperature higher than the
decrease in temperature. The temperature of the substrate (wafer) W
is thus kept constant at high precision.
[0115] A temperature t1 of the chuck 6 is set at, e.g., the same
temperature as a predetermined temperature at which the substrate
(wafer) W is to be processed in the process chamber 1.
[0116] In this case, a change in temperature of the substrate
(wafer) W represents the curve shown in FIG. 6A. A temperature t of
the substrate (wafer) W comes close gradually to a predetermined
temperature at which the substrate (wafer) W is to be processed in
the process chamber 1 (e.g., t1). That is, the temperature t of the
substrate (wafer) W becomes stable in the range of the
predetermined temperature after a time T1.
[0117] To improve a throughput, if a time for which the substrate
(wafer) W is held by the chuck 6 is to be shortened, the
temperature of the chuck 6 can be set at a temperature t2 higher
than the temperature t1 at which the substrate (wafer) W is to be
processed in the process chamber 1 (e.g., 30.degree. C. is set with
respect to the processing temperature of 23.degree. C.).
[0118] In this case, a change in temperature of the substrate
(wafer) W represents the curve shown in FIG. 6B. The temperature of
the substrate (wafer) W gradually increases after the elapse of a
time T3, and then closes gradually to the temperature t2 of the
chuck 6. When the time T3 has elapsed, the controller 30 controls
the chuck 6 to lift the substrate (wafer) W by its three pins 63
and to end thermal regulation operation for the substrate (wafer)
W. The controller 30 controls the chuck 6 to stop thermal
regulation to the substrate (wafer) W when the time T3 has elapsed,
thereby making the temperature at which the substrate (wafer) W at
a predetermined temperature at which the substrate (wafer) W is to
be processed by the process chamber 1. This has an advantage in
that the time T3 for which the substrate holding chuck 6 holds the
substrate (wafer) W is shorter than the time T1.
[0119] In this case, after a predetermined time (e.g., the t3) has
elapsed since the three pins 63 of the chuck 6 move the substrate
(wafer) W downward, the controller 30 can control the chuck 6 to
lift the substrate (wafer) W by its three pins 63, and control the
transfer mechanism to transfer the substrate (wafer) W.
[0120] Note that considering heat transfer from the chuck to the
substrate (wafer) W and heat conduction of the chuck itself, the
chuck 6 is preferably a good heat conductor, such as copper.
[0121] In this embodiment, an electrostatic suction chuck is
preferably used as the chuck 6. Unlike the vacuum suction chuck 6
shown in FIGS. 4A and 4B, the electrostatic suction chuck has a
characteristic in that its suction force is constant regardless of
the pressure of the ambient gas. The vacuum suction chuck 6 shown
in FIGS. 4A and 4B has a vacuum suction groove 65 along a
concentric circle to vacuum-chuck and hold the substrate (wafer)
W.
[0122] To prevent particles from attaching to the lower surface of
the substrate (wafer) W, the substrate holding chuck 6 in the
load-lock chamber 3 preferably has a pin-chuck structure. In the
pin-chuck structure, thermal transfer from the chuck 6 to the
substrate (wafer) W similarly occurs through contact portions. The
ambient gas of the pins is exhausted along with evacuation, and the
time T3 depends on a decrease in thermal transfer along with a
decrease in pressure of the ambient gas of the pins and the length
of time for which the wafer is held by the chuck 6, thereby
controlling the time T3 to be constant, as described above.
[0123] The thermoregulator used as a heating means is not limited
to the afore-mentioned heater, and may have a structure so as to
cause a fluid to flow, such as a thermal-regulated gas or liquid in
holes 66 for circulation formed along a plurality of concentric
circles in the chuck 6, as shown in FIGS. 5A and 5B.
[0124] The preferred embodiment of the present invention represents
an example of controlling all the parameters to become constant,
but is not limited to this. A parameter which is to reach a
predetermined value without any control, and the like, may not be
controlled.
[0125] In the present invention, all the parameters are controlled
to become constant. However, the present invention is not limited
to this, and at least one parameter may be so controlled as to
become constant.
[0126] For example, the parameter which is to become constant in a
predetermined range without any control, a parameter which hardly
affects any processing for the substrate (wafer) W and need not be
controlled, and the like, may not be controlled.
[0127] (Another Embodiment of A Substrate Processing Apparatus)
[0128] In another embodiment to which the present invention is
applied, the atmosphere of a process chamber 1, which is the first
chamber having a process station (exposure process portion) 20,
which performs exposure, and the like, is a vacuum atmosphere.
[0129] A load-lock chamber 3 according to the present invention to
purge the atmosphere between the process chamber 1 and a substrate
supply portion 10 in the air is formed, and a preliminary chamber 2
is formed between the load-lock chamber 3 and process chamber
1.
[0130] A second transfer mechanism 8 for transferring a substrate
between the load-lock chamber 3 and process station (exposure
process portion) 20 is formed in the preliminary chamber 2.
[0131] The transfer hand of the second transfer mechanism 8 is so
formed as to make an area in contact with a substrate (wafer) W
minimum.
[0132] For example, the transfer hand of the second transfer
mechanism 8 supports the lower surface of the substrate (wafer) W
by one or a plurality of pins and opposes the side surfaces of the
substrate to grippers or wall members which are spaced at an
appropriate gap so as to prevent the substrate from moving in the
transfer hand during the transfer. These grippers or walls may have
a pin shape, which minimizes an area in contact with the
substrate.
[0133] The transfer hand of the second transfer mechanism 8 has
three or more conical pins, each of which has a sloping portion on
its side surface abutting against the side surface of the substrate
(wafer) W, and the remaining portion not in contact with the
substrate.
[0134] In a vacuum atmosphere, since no heat exchange is performed
between atmospheric gas and the substrate (wafer) W, the
temperature of the substrate unloaded from the load-lock chamber 3
changes depending on contact with the second transfer mechanism
8.
[0135] To suppress a change in the temperature of the substrate due
to contact of the transfer hand of the second transfer mechanism 8
with the substrate (wafer) W, the contact area of the second
transfer mechanism 8 and the substrate (wafer) W is preferably made
to be small, as described above.
[0136] With this structure, the substrate (wafer) W unloaded from
the load-lock chamber 3 is transferred to the process station
(exposure process portion) 20 while keeping the temperature of the
substrate (wafer) W almost constant.
[0137] As described above, in this embodiment, the temperature of
the substrate (wafer) W falls within a predetermined temperature
range at a timing when the substrate is unloaded from the load-lock
chamber 3 by the second transfer mechanism 8.
[0138] Thus, the substrate (wafer) W transferred to the process
station (exposure process portion) 20 already has a temperature
which falls within the range of a predetermined temperature at
which the substrate (wafer) W is to be processed in the process
chamber. This requires no thermal regulation in the process station
(exposure process portion), so that exposure processing can be
immediately started, thereby increasing the throughput.
[0139] (Embodiment of an Exposure Apparatus Main Body)
[0140] An exposure apparatus main body (exposure process portion)
20 according to an embodiment of the present invention will be
described, by exemplifying a scanning exposure apparatus. FIG. 9 is
a front view showing an example of the main structure of the
scanning exposure apparatus main body according to the preferred
embodiment of the present invention. This exposure apparatus main
body is arranged in the above process chamber serving as the first
process chamber, and performs exposure for a substrate (wafer). In
FIG. 9, a lens barrel surface plate 96 is supported by a floor/base
91 via a damper 98. The lens barrel surface plate 96 supports a
reticle stage surface plate 94, and also supports a projection
optical system 97 arranged between a reticle stage 95 and a wafer
stage 93.
[0141] The wafer stage 93 having a chuck 90 is supported on a stage
surface plate 92 arranged on the floor/base 91, and holds the
substrate (wafer) set on the chuck 90 to position the substrate
(wafer). The reticle stage 95 is supported on the reticle stage
surface plate 94 supported by the lens barrel surface plate 96, and
can move while mounting the reticle serving as a master on which a
circuit pattern is formed. Exposure light for exposing the reticle
mounted on the reticle stage 95 onto the substrate (wafer) on the
wafer stage 93 is emitted from an illumination optical system
99.
[0142] The wafer stage 93 is scanned in synchronism with the
reticle stage 95. During scanning of the reticle stage 95 and the
wafer stage 93, the positions of both stages are continuously
detected by interferometers, respectively, and the detection
results are fed back to driving units of the reticle stage 95 and
the wafer stage 93. Hence, the scanning start positions of both the
stages can be accurately synchronized, and the scanning speed in a
constant-speed scanning region can be controlled with high
precision. While both the stages scan the projection optical system
97, the reticle pattern is exposed on the substrate (wafer), and
the circuit pattern is transferred.
[0143] (Embodiment of a Semiconductor Production System)
[0144] A production system for a semiconductor device (e.g., a
semiconductor chip such as an IC or LSI, a liquid crystal panel, a
CCD, a thin-film magnetic head, a micromachine, or the like), using
an apparatus according to the present invention, will be
exemplified. The system performs maintenance services such as
trouble-shooting, periodic maintenance, and software distribution
for manufacturing apparatuses installed in a semiconductor
manufacturing factory by utilizing a computer network, or the like,
outside the manufacturing factory.
[0145] FIG. 10 shows the overall system cut out at a given angle.
In FIG. 10, reference numeral 1101 denotes an office of a vendor
(e.g., an apparatus supply manufacturer), which provides a
semiconductor device manufacturing apparatus. Examples of the
manufacturing apparatus are semiconductor manufacturing apparatuses
for performing various processes used in a semiconductor
manufacturing factory, such as pre-process apparatuses (e.g., a
lithography apparatus including an exposure apparatus, a resist
processing apparatus, and an etching apparatus, an annealing
apparatus, a film formation apparatus, a planarization apparatus,
and the like) and post-process apparatuses (e.g., an assembly
apparatus, an inspection apparatus, and the like). The office 101
comprises a host management system 1108 which provides a
maintenance database for the manufacturing apparatus, a plurality
of operation terminal computers 1110, and a LAN (Local Area
Network) 1109, which connects the host management system 1108 and
computers 1110 to build an intranet, or the like. The host
management system 1108 has a gateway for connecting the LAN 1109 to
the Internet 1105 serving as an external network of the office, and
a security function for limiting external access.
[0146] Reference numerals 1102 to 1104 denote manufacturing
factories of the semiconductor manufacturer as users of the
manufacturing apparatuses. The manufacturing factories 1102 to 1104
may belong to different manufacturers or the same manufacturer
(e.g., a pre-process factory, a post-process factory, and the
like). Each of the factories 1102 to 1104 is equipped with a
plurality of manufacturing apparatuses 1106, for example, a LAN
(Local Area Network) 1111, which connects these apparatuses 1106 to
construct an intranet, and a host management system 1107 serving as
a monitoring apparatus which monitors the operation status of each
manufacturing apparatus 1106. The host management system 1107 in
each of the factories 1102 to 1104 has a gateway for connecting the
LAN 1111 in the factory to the Internet 1105 serving as an external
network of the factory. Each factory can access the host management
system 1108 of the office 1101 of a vendor from the LAN 1111 via
the Internet 1105. The security function of the host management
system 1108 authorizes access of only a limited user. More
specifically, the factory can notify the vendor via the Internet
1105 of status information (e.g., the symptom of a manufacturing
apparatus in trouble), representing the operation status of each
manufacturing apparatus 1106. Also, the factory can receive, from
the vendor, response information (e.g., information designating a
remedy against the trouble, or remedy software or data)
corresponding to the notification, or maintenance information such
as the latest software or help information. Data communication
between the factories 1102 to 1104 and the office 1101 of the
vendor and data communication via the LAN 1111 in each factory
adopt a communication protocol (TCP/IP) generally used in the
Internet. Instead of using the Internet as an external network of
the factory, a high-security dedicated network (e.g., an ISDN),
which inhibits access of a third party, can be adopted. The host
management system is not limited to the one provided by the vendor.
The user may construct a database and set the database on an
external network, and the host management system may authorize
access to the database from a plurality of user factories.
[0147] FIG. 11 is a view showing the concept of the overall system
of this embodiment that is cut out at a different angle from FIG.
10. In the above example, a plurality of user factories having
manufacturing apparatuses and the management system of the
manufacturing apparatus vendor are connected via an external
network, and production management of each factory or information
about at least one manufacturing apparatus is communicated via the
external network. In the example of FIG. 11, a factory having
manufacturing apparatuses provided by a plurality of vendors and
the management systems of the vendors for these manufacturing
apparatuses are connected via the external network of the factory,
and maintenance information of each manufacturing apparatus is
communicated. In FIG. 11, reference numeral 1201 denotes a
manufacturing factory of a manufacturing apparatus user (e.g., a
semiconductor device manufacturer). Manufacturing apparatuses for
performing various processes, e.g., an exposure apparatus 1202, a
resist processing apparatus 1203, and a film formation apparatus
1204, are installed in the manufacturing line of the factory. FIG.
11 shows only one manufacturing factory 1201, but a plurality of
factories are networked in practice. The respective apparatuses in
the factory are connected to each other by a LAN 1206 to build an
intranet, and a host management system 1205 manages the operation
of the manufacturing line.
[0148] The offices of vendors (e.g., apparatus supply
manufacturers), such as an exposure apparatus manufacturer 1210, a
resist processing apparatus manufacturer 1220, and a film formation
apparatus manufacturer 1230 comprise host management systems 1211,
1221, and 1231 for executing remote maintenance for the supplied
apparatuses. Each host management system has a maintenance database
and a gateway for an external network, as described above. The host
management system 1205 for managing the apparatuses in the
manufacturing factory of the user, and the management systems 1211,
1221, and 1231 of the vendors for the respective apparatuses are
connected via the Internet or dedicated network serving as an
external network 1200. In this system, if trouble occurs in any one
of the manufacturing apparatuses along the manufacturing line, the
operation of the manufacturing line stops. This trouble can be
quickly solved by remote maintenance from the vendor of the
apparatus in trouble via the Internet 1200. This can minimize the
stoppage of the manufacturing line.
[0149] Each manufacturing apparatus in the semiconductor
manufacturing factory comprises a display, a network interface, and
a computer, which executes network access software and apparatus
operating software, which are stored in a storage device. The
storage device is a built-in memory, a hard disk, or a network file
server. The network access software includes a dedicated or
general-purpose web browser, and provides a user interface with a
window, as shown in FIG. 12, on the display. While referring to
this window, the operator who manages manufacturing apparatuses in
each factory inputs, into input fields on the windows, pieces of
information, such as the model of manufacturing apparatus 1401,
serial number 1402, subject of trouble 1403, date of occurrence of
trouble 1404, degree of urgency 1405, symptom 1406, remedy 1407,
and progress 1408. The pieces of input information are transmitted
to the maintenance database via the Internet, and appropriate
maintenance information is sent back from the maintenance database
and provided on the display. The user interface provided by the web
browser realizes hyperlink functions 1410 to 1412, as shown in FIG.
12. This allows the operator to access more detailed information of
each item, download the latest-version software to be used for a
manufacturing apparatus from a software library provided by a
vendor, and download an operation guide (help information) as a
reference for the operator in the factory. The maintenance
information provided from the maintenance database includes
information about the present invention described above. The
software library also provides the latest-version software for
implementing the present invention.
[0150] A semiconductor device manufacturing process using the
above-described production system will be explained. FIG. 13 shows
the flow of the whole manufacturing process of the semiconductor
device. In step 1 (circuit design), a semiconductor device circuit
is designed. In step 2 (mask formation), a mask having the designed
circuit pattern is formed. In step 3 (wafer formation), a substrate
(wafer) is formed by using a material such as silicon. In step 4
(wafer process), called a pre-process, an actual circuit is formed
on the substrate (wafer) by lithography using the prepared mask and
substrate (wafer). Step 5 (assembly), called a post-process, is the
step of forming a semiconductor chip by using the substrate (wafer)
formed in step 4, and includes an assembly process (dicing and
bonding) and a packaging process (chip encapsulation). In step 6
(inspection), the semiconductor device manufactured in step 5
undergoes inspections, such as an operation confirmation test and a
durability test. After these steps, the semiconductor device is
completed and shipped (step 7). The pre-process and post-process
are performed in separate dedicated factories, and each of the
factories receives maintenance by the above-described remote
maintenance system. Information for production management and
apparatus maintenance is communicated between the pre-process
factory and the post-process factory via the Internet or dedicated
network.
[0151] FIG. 14 shows the detailed flow of the wafer process. In
step 11 (oxidation), the substrate (wafer) surface is oxidized. In
step 12 (CVD), an insulating film is formed on the substrate
(wafer) surface. In step 13 (electrode formation), an electrode is
formed on the substrate (wafer) by vapor deposition. In step 14
(ion implantation), ions are implanted in the substrate (wafer). In
step 15 (resist processing), a photosensitive agent is applied to
the substrate (wafer). In step 16 (exposure), the above-mentioned
exposure apparatus exposes the substrate (wafer) to the circuit
pattern of a mask, and prints the circuit pattern on the substrate.
In step 17 (developing), the exposed substrate (wafer) is
developed. In step 18 (etching), the resist is etched except for
the developed resist image. In step 19 (resist removal), an
unnecessary resist after etching is removed. These steps are
repeated to form multiple circuit patterns on the substrate
(wafer). A manufacturing apparatus used in each step undergoes
maintenance by the remote maintenance system, which prevents
trouble in advance. Even if trouble occurs, the manufacturing
apparatus can be quickly recovered. The productivity of the
semiconductor device can be increased in comparison with the prior
art.
[0152] According to a preferred embodiment of the present
invention, since the temperature of the substrate (wafer) loaded
into the apparatus via the load-lock chamber reaches the
predetermined temperature at the time of loading, the substrate
(wafer) can be immediately processed, e.g., subjected to exposure,
thereby improving the throughput.
[0153] In particular, the larger effect can be attained in the
apparatus with the evacuated chamber.
[0154] As many apparently widely different embodiments of the
present invention can be made without departing from the spirit and
scope thereof, it is to be understood that the invention is not
limited to the specific embodiments thereof except as defined in
the appended claims.
* * * * *