U.S. patent application number 17/484379 was filed with the patent office on 2022-08-18 for method of manufacturing semiconductor device, substrate processing method, substrate processing apparatus, and recording medium.
This patent application is currently assigned to KOKUSAI ELECTRIC CORPORATION. The applicant listed for this patent is KOKUSAI ELECTRIC CORPORATION. Invention is credited to Naofumi OHASHI, Takashi YAHATA, Ryuji YAMAMOTO.
Application Number | 20220262632 17/484379 |
Document ID | / |
Family ID | |
Filed Date | 2022-08-18 |
United States Patent
Application |
20220262632 |
Kind Code |
A1 |
YAHATA; Takashi ; et
al. |
August 18, 2022 |
METHOD OF MANUFACTURING SEMICONDUCTOR DEVICE, SUBSTRATE PROCESSING
METHOD, SUBSTRATE PROCESSING APPARATUS, AND RECORDING MEDIUM
Abstract
There is provided a technique that includes: (a) loading a
substrate into a process container; (b) heating the substrate by
supplying a first gas, which is heated when passing through a first
heater installed at a first gas supply line, to the substrate via a
gas supplier; (c) supplying a second gas, which flows through a
second gas supply line different from the first gas supply line, to
the substrate mounted on a substrate mounting table in the process
container, via the gas supplier; and (d) lowering a temperature of
the gas supplier by supplying a third gas, which has a temperature
lower than that of the first gas, to the gas supplier between (b)
and (c).
Inventors: |
YAHATA; Takashi; (Toyama,
JP) ; OHASHI; Naofumi; (Toyama, JP) ;
YAMAMOTO; Ryuji; (Tokyo, JP) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
KOKUSAI ELECTRIC CORPORATION |
Tokyo |
|
JP |
|
|
Assignee: |
KOKUSAI ELECTRIC
CORPORATION
Tokyo
JP
|
Appl. No.: |
17/484379 |
Filed: |
September 24, 2021 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
17206024 |
Mar 18, 2021 |
11145505 |
|
|
17484379 |
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International
Class: |
H01L 21/02 20060101
H01L021/02; C23C 16/52 20060101 C23C016/52; H01J 37/32 20060101
H01J037/32; H01L 21/67 20060101 H01L021/67; C23C 16/46 20060101
C23C016/46; C23C 16/50 20060101 C23C016/50 |
Foreign Application Data
Date |
Code |
Application Number |
Feb 15, 2021 |
JP |
2021-021417 |
Claims
1. A substrate processing apparatus, comprising: a process
container in which a substrate is accommodated; a transfer device
configured to transfer the substrate into the process container; a
substrate mounting table configured to mount the substrate in the
process container; a gas supplier configured to supply a gas to the
substrate in the process container; a first gas supply line
including a first heater and being configured to supply a first gas
via the gas supplier; a second gas supply line configured to supply
a second gas via the gas supplier; a third gas supply line
configured to supply a third gas to the gas supplier; at least one
first gas supply port installed at the gas supplier and being in
fluid communication with the first gas supply line; and at least
one second gas supply port installed at the gas supplier and being
in fluid communication with the second gas supply line.
2. The substrate processing apparatus of claim 1, further
comprising: a second heater installed at the substrate mounting
table; and a lift pin configured to hold the substrate over the
substrate mounting table.
3. The substrate processing apparatus of claim 1, wherein the third
gas supply line is connected to the first gas supply line.
4. The substrate processing apparatus of claim 1, wherein the third
gas supply line is connected to the gas supplier in parallel with
the first gas supply line.
5. The substrate processing apparatus of claim 1, wherein the gas
supplier includes: a buffer space configured to supply the first
gas to the substrate; and an exhauster configured to exhaust the
third gas supplied to the buffer space.
6. The substrate processing apparatus of claim 1, further
comprising: a fourth gas supply line configured to supply a fourth
gas to a transfer chamber installed in the process container; and a
fourth heater installed at the fourth gas supply line.
7. The substrate processing apparatus of claim 1, wherein the gas
supplier is configured to face an upper surface of the substrate,
wherein the first gas supply line is connected to a central side of
the gas supplier, and wherein the third gas supply line is
connected to an outer peripheral side of the gas supplier.
8. The substrate processing apparatus of claim 1, wherein the at
least one first gas supply port includes one or more ports
installed at a central side to the substrate and one or more ports
installed at an outer peripheral side to the substrate, and wherein
the one or more ports installed at the central side to the
substrate and the one or more ports installed at the outer
peripheral side to the substrate are different from each other in
at least one selected from the group of numbers of the one or more
ports and sizes of the one or more ports.
9. The substrate processing apparatus of claim 1, wherein the first
gas is at least one selected from the group of a N.sub.2 gas, a
H.sub.2 gas, and a He gas.
10. The substrate processing apparatus of claim 1, wherein the
third gas is at least one selected from the group of a N.sub.2 gas,
a H.sub.2 gas, a He gas, a diluted H.sub.2 gas, and an activated
H.sub.2 gas.
11. The substrate processing apparatus of claim 1, wherein the
first gas and the third gas are an inert gas, and the second gas is
a processing gas.
12. The substrate processing apparatus of claim 1, wherein the
first gas and the third gas are the same gas.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This application is a continuation of U.S. Ser. No.
17/206,024 filed on Mar. 18, 2021, which is based upon and claims
the benefit of priority from Japanese Patent Application No.
2021-021417, filed on Feb. 15, 2021, the entire contents of which
are incorporated herein by reference.
TECHNICAL FIELD
[0002] The present disclosure relates to a method of manufacturing
a semiconductor device, a substrate processing method, a substrate
processing apparatus, and a recording medium.
BACKGROUND
[0003] As a process of manufacturing a semiconductor device by
using a single-wafer apparatus that processes substrates one by
one, a step of supplying a gas to a substrate to form a film on the
substrate may be often carried out.
SUMMARY
[0004] Some embodiments of the present disclosure provide a
technique capable of improving a processing uniformity and a
throughput for each substrate.
[0005] According to some embodiments of the present disclosure,
there is provided a technique that includes: (a) loading a
substrate into a process container; (b) heating the substrate by
supplying a first gas, which is heated when passing through a first
heater installed at a first gas supply line, to the substrate via a
gas supplier; (c) supplying a second gas, which flows through a
second gas supply line different from the first gas supply line, to
the substrate mounted on a substrate mounting table in the process
container, via the gas supplier; and (d) lowering a temperature of
the gas supplier by supplying a third gas, which has a temperature
lower than that of the first gas, to the gas supplier between (b)
and (c).
BRIEF DESCRIPTION OF DRAWINGS
[0006] The accompanying drawings, which are incorporated in and
constitute a part of the specification, illustrate some embodiments
of the present disclosure.
[0007] FIG. 1 is a schematic configuration view of a substrate
processing apparatus suitably used in embodiments of the present
disclosure, in which a portion of a process furnace is shown in a
vertical cross section.
[0008] FIG. 2 is a schematic configuration diagram of a controller
280 of a substrate processing apparatus suitably used in some
embodiments of the present disclosure, in which a control system of
the controller 280 is shown in a block diagram.
[0009] FIG. 3 is a schematic configuration view of a main part of a
substrate processing apparatus suitably used in a first
modification of the present disclosure.
[0010] FIG. 4 is a schematic configuration view of a main part of a
substrate processing apparatus suitably used in other embodiments
of the present disclosure.
[0011] FIG. 5 is a schematic configuration view of a main part of a
substrate processing apparatus suitably used in other embodiments
of the present disclosure.
DETAILED DESCRIPTION
Embodiments of the Present Disclosure
[0012] Some embodiments of the present disclosure will now be
described mainly with reference to FIG. 1. Figures used in the
following description are schematic, and dimensional relationships,
ratios, and the like among elements on the figures do not always
match actual ones. Further, dimensional relationships, ratios, and
the like among elements on the figures do not always match each
other even among a plurality of figures.
(1) CONFIGURATION OF SUBSTRATE PROCESSING APPARATUS
[0013] As shown in FIG. 1, a substrate processing apparatus 100
includes a process container 202. The process container 202 is
configured as, for example, a flat sealed container having a
circular cross section. The process container 202 includes an upper
container 2021 made of, for example, a non-metal material such as
quartz or ceramics, and a lower container 2022 made of, for
example, a metal material such as aluminum (Al) or stainless steel
(SUS). In the process container 202, a process chamber (process
space) 201 in which a wafer 200 such as a silicon wafer as a
substrate is processed is formed at an upper side (a space above a
substrate mounting stand 212 as a substrate mounting table to be
described below) of the process container 202, and a transfer
chamber (transfer space) 203 configured to transfer the wafer 200
is formed in a space surrounded by the lower container 2022 on a
lower side of the process container 202. A transfer container 700
is installed to be adjacent to the lower container 2022 of the
process container 202. A transfer chamber (transfer space) 600
configured to transfer the wafer 200 is installed in the transfer
container 700, and a transfer mechanism 500 such as a transfer
robot is installed in the transfer chamber 600.
[0014] A substrate loading/unloading port 206 is installed at a
side surface of the lower container 2022. The substrate
loading/unloading port 206 is configured to be capable of being
opened/closed by a gate valve 205. By opening the gate valve 205,
an interior of the process container 202 (the transfer space 203)
and an interior of the transfer container 700 (the transfer chamber
600) may be in fluid communication with each other such that the
wafer 200 may be loaded/unloaded in/out of the transfer space 203
by the transfer mechanism 500. A plurality of lift pins 207
configured to temporarily support the wafer 200 are installed at a
bottom portion of the lower container 2022.
[0015] A substrate support (susceptor) 210 configured to support
the wafer 200 is installed at the process chamber 201. The
substrate support 210 mainly includes a substrate mounting surface
(substrate mounting plate) 211 on which the wafer 200 is mounted, a
substrate mounting stand 212 having the substrate mounting surface
211 formed thereon, and a heater 213 as a second heating part
included in the substrate mounting stand 212. The substrate support
210 further includes a temperature measurement terminal 216
configured to measure a temperature of the heater 213. The
temperature measurement terminal 216 is connected to a temperature
measuring part 221 via a wiring 220. The substrate mounting surface
(substrate mounting plate) 211 may also be referred to as a
susceptor.
[0016] The substrate mounting stand 212 is provided with
through-holes 214 through which the lift pins 207 penetrate, at
positions corresponding to the lift pins 207. A wiring 222
configured to supply electric power is connected to the heater 213.
The wiring 222 is connected to a heater electric power controller
223.
[0017] The temperature measuring part 221 and the heater electric
power controller 223 are connected to a controller 280 to be
described below. The controller 280 transmits control information
to the heater electric power controller 223 based on temperature
information measured by the temperature measuring part 221. The
heater electric power controller 223 controls the heater 213 based
on the received control information.
[0018] The substrate mounting stand 212 is supported by a shaft
217. The shaft 217 penetrates the bottom portion of the process
container 202 and is further connected to an elevator 218 outside
the process container 202.
[0019] The elevator 218 mainly includes a support shaft 218a
configured to support the shaft 217, and an actuator 218b
configured to elevate and/or rotate the support shaft 218a. The
actuator 218b includes, for example, an elevating mechanism 218c
including a motor configured to perform an elevation, and a
rotation mechanism 218d such as a gear configured to rotate the
support shaft 218a. A smoothing agent such as grease is applied on
the elevating mechanism 218c and the rotation mechanism 218d for
their smooth operations. When there is no need to rotate the
support shaft 218a, the rotation mechanism 218d may be omitted. In
this case, the actuator 218b is configured to raise or lower the
support shaft 218a.
[0020] The elevator 218 may include an instruction part 218e which
is a part of the elevator 218 and configured to instruct the
actuator 218b to perform the elevation and/or the rotation. In that
case, the instruction part 218e is electrically connected to the
controller 280. Further, in that case, the instruction part 218e
controls the actuator 218b based on an instruction of the
controller 280. As described below, the actuator 218b controls the
elevating operation of the support shaft 218a such that the
substrate mounting stand 212 moves to a wafer transfer position (a
position of the substrate mounting stand 212 indicated by a broken
line in FIG. 1) or a wafer processing position (a position of the
substrate mounting stand 212 in FIG. 1).
[0021] By actuating the elevator 218 to raise or lower the shaft
217 and the substrate mounting stand 212, the substrate mounting
stand 212 may raise or lower the wafer 200 mounted on the substrate
mounting surface 211. A circumference of a lower end portion of the
shaft 217 is covered with a bellows 219, whereby the interior of
the process chamber 201 is kept airtight.
[0022] The substrate mounting stand 212 is lowered such that the
substrate mounting surface 211 is at the position of the substrate
loading/unloading port 206 (the wafer transfer position) when the
wafer 200 is transferred, and is raised such that the wafer 200 is
at the processing position (the wafer processing position) in the
process chamber 201 when the wafer 200 is processed.
[0023] When the substrate mounting stand 212 is lowered to the
wafer transfer position, the upper end portions of the lift pins
207 protrude from the upper surface of the substrate mounting
surface 211 such that the lift pins 207 are in a state where the
wafer 200 may be supported from below by the lift pins 207 (see the
substrate mounting stand 212 indicated by the broken line and the
wafer 200 indicated by a dotted line in FIG. 1). Further, when the
substrate mounting stand 212 is raised to the wafer processing
position with the wafer 200 supported by the lift pins 207, the
lift pins 207 is buried from the upper surface of the substrate
mounting surface 211 while the substrate mounting stand 212 is
being raised, whereby the wafer 200 is supported from below by the
substrate mounting surface 211 supports the wafer 200.
[0024] A shower head 230 as a gas distribution mechanism is
installed at the upper portion of the process chamber 201 (an
upstream side of gas flow) and at a position facing the substrate
mounting surface 211. A lid 231 of the shower head 230 is made of,
for example, electrically conductive and thermally conductive
metal. In the following description, for convenience of
description, the upstream side of the gas flow in a space where a
gas may flow is also simply referred to as an upstream side.
Further, in the following description, for convenience of
description, a downstream side of gas flow in a space where a gas
may flow is also simply referred to as a downstream side.
[0025] Further, the lid 231 of the shower head is provided with a
through-hole 231a. A gas supply pipe 241 is inserted in the
through-hole 231a. The gas supply pipe 241 inserted in the
through-hole 231a includes a leading end 241a inserted in the
shower head 230, and a flange 241b fixed to the lid 231. The gas
supply pipe 241 has a function of distributing a gas supplied into
a shower head buffer chamber 232 which is a space formed in the
shower head 230. The leading end 241a of the gas supply pipe 241 is
formed in, for example, a columnar shape and is provided with a
distribution hole on a side surface of the columnar shape. A gas
supplied from the gas supply pipe 241 is supplied into the shower
head buffer chamber 232 via the distribution hole formed at the
leading end 241a.
[0026] Further, the shower head 230 includes a gas supplier 234
configured to supply a gas supplied from a gas supply system to be
described below, to the wafer 200. The shower head buffer chamber
232 is located at the upstream side of the gas supplier 234, and
the process chamber 201 is located on the downstream side of the
gas supplier 234. The gas supplier 234 is disposed on the upper
side of the substrate mounting surface 211 to face the substrate
mounting surface 211. The gas supplier 234 is provided with a
plurality of through-holes 234b as a second gas supply port. Each
of the through-holes 234b is constituted by a tubular structure
(tubular portion) 234d. The tubular structure 234d is provided to
penetrate an upper wall 234e of the gas supplier 234. The upstream
side of the tubular structure 234d is in fluid communication with
the shower head buffer chamber 232, and the downstream side of the
tubular structure 234d is in fluid communication with the process
chamber 201. Therefore, the shower head buffer chamber 232 is in
fluid communication with the process chamber 201 via the plurality
of through-holes 234b formed at the gas supplier 234.
[0027] A buffer space 233 is formed by a region constituting the
gas supplier 234 and surrounded by the upper wall 234e facing the
substrate mounting surface 211 and a side wall 234f. The buffer
space 233 is configured as a part of the gas supplier 234.
[0028] The gas supplier 234 is provided with a plurality of
through-holes 234a as a first gas supply port to be adjacent to the
through-holes 234b. Each of the through-holes 234a is constituted
by a tubular structure (tubular portion) 234g. The tubular
structure 234g is installed to protrude into the buffer space 233.
The upstream side of the tubular structure 234g is in fluid
communication with the buffer space 233, and the downstream side of
the tubular structure 234g is in fluid communication with the
process chamber 201. Therefore, the buffer space 233 is in fluid
communication with the process chamber 201 via the plurality of
through-holes 234a formed at the gas supplier 234.
[0029] A common gas supply pipe 242 is connected to the gas supply
pipe 241 inserted in the through-hole 231a. Interiors of the gas
supply pipe 241 and the common gas supply pipe 242 are in fluid
communication with each other. According to the aforementioned
configuration, a gas supplied from the common gas supply pipe 242
is supplied into the shower head 230 via the gas supply pipe 241
and the through-hole 231a.
[0030] Gas supply pipes 243a, 244a, and 245a are connected to the
common gas supply pipe 242. Among them, the gas supply pipe 244a is
connected to the common gas supply pipe 242 via a remote plasma
unit (RPU) 244e as a plasma generator (plasma source).
[0031] At the gas supply pipes 243a, 244a, and 245a, gas supply
sources 243b, 244b, and 245b, MFCs (Mass Flow Controllers) 243c,
244c, and 245c, which are flow rate controllers, and valves 243d,
244d, and 245d, which are opening/closing valves, are installed
sequentially from the upstream side of gas flow, respectively.
[0032] Downstream ends of gas supply pipes 246a and 247a are
connected to the gas supply pipes 243a and 244a at the downstream
side of the valves 243d and 244d, respectively. At the gas supply
pipes 246a and 247a, gas supply sources 246b and 247b, MFCs 246c
and 247c, and valves 246d and 247d as opening/closing valves are
respectively installed sequentially from the upstream side of gas
flow. The gas supply pipes 243a to 247a are made of, for example, a
metal material such as SUS.
[0033] A precursor gas is supplied from the gas supply source 243b
into the shower head 230 via the MFC 243c, the valve 243d, the gas
supply pipe 243a, the common gas supply pipe 242, the gas supply
pipe 241, and the through-hole 231a.
[0034] A reaction gas is supplied from the gas supply source 244b
into the shower head 230 via the MFC 244c, the valve 244d, the gas
supply pipe 244a, the RPU 244e, the common gas supply pipe 242, the
gas supply pipe 241, and the through-hole 231a. At this time, the
reaction gas is excited into a plasma state by the RPU 244e and is
supplied to the wafer 200 in the process chamber 201 via the common
gas supply pipe 242, the gas supply pipe 241, the through-hole
231a, and the shower head 230.
[0035] An inert gas and a cleaning gas are supplied from the gas
supply source 245b into the shower head 230 via the MFC 245c, the
valve 245d, the gas supply pipe 245a, the common gas supply pipe
242, the gas supply pipe 241, and the through-hole 231a. The inert
gas is mainly supplied from the gas supply source 245b when the
wafer 200 is processed, and the cleaning gas is mainly supplied
from the gas supply source 245b when the interior of the shower
head 230 and the interior of the process chamber 201 are cleaned.
The inert gas acts as a purge gas that purges a retained gas or a
residual gas in the process container 202 (the process chamber 201)
and in the shower head 230. In addition, the inert gas may also act
as a dilution gas that dilutes each gas or as a carrier gas that
promotes the flow of each gas. As the cleaning gas, a halogen-based
gas, for example, a fluorine (F)-containing gas or the like, may be
used.
[0036] An inert gas is supplied from the gas supply source 246b
into the shower head 230 via the MFC 246c, the valve 246d, the gas
supply pipe 246a, the common gas supply pipe 242, the gas supply
pipe 241, and the through-hole 231a. The inert gas acts as a purge
gas, a carrier gas, a dilution gas, or the like.
[0037] An inert gas is supplied from the gas supply source 247b
into the shower head 230 via the MFC 247c, the valve 247d, the gas
supply pipe 247a, the RPU 244e, the common gas supply pipe 242, the
gas supply pipe 241, and the through-hole 231a. The inert gas acts
as a purge gas, a carrier gas, a dilution gas, or the like.
[0038] A precursor gas supply system 243 mainly includes the gas
supply pipe 243a, the MFC 243c, and the valve 243d. The gas supply
source 243b may be included in the precursor gas supply system 243.
A first inert gas supply system mainly includes the gas supply pipe
246a, the MFC 246c, and the valve 246d. The gas supply source 246b
may be included in the first inert gas supply system. A reaction
gas supply system 244 mainly includes the gas supply pipe 244a, the
MFC 244c, and the valve 244d. The gas supply source 244b may be
included in the reaction gas supply system 244. A second inert gas
supply system mainly includes the gas supply pipe 247a, the MFC
247c, and the valve 247d. The gas supply source 247b may be
included in the second inert gas supply system. A gas supply system
245 mainly includes the gas supply pipe 245a, the MFC 245c, and the
valve 245d. The gas supply source 245b may be included in the gas
supply system 245.
[0039] Further, the first inert gas supply system, the gas supply
pipe 241, and the common gas supply pipe 242 may be included in the
precursor gas supply system 243. Further, the second inert gas
supply system, the RPU 244e, the gas supply pipe 241, and the
common gas supply pipe 242 may be included in the reaction gas
supply system 244.
[0040] Each or both of the precursor gas and the reaction gas are
also referred to as a processing gas or a second gas, and each or
both of the precursor gas supply system 243 and the reaction gas
supply system 244 are also referred to as a processing gas supply
system, a second gas supply system, or a second gas supply line.
Since the inert gas is a non-reactive gas and the processing gas
(precursor gas or reaction gas) is a reactive gas, the processing
gas may also be referred to as a reactive gas. Further, when a film
is formed by the processing gas, the processing gas may also be
referred to as a film-forming gas.
[0041] A gas introduction hole configured to supply a gas into the
buffer space 233 is formed at the upper wall 234e of the gas
supplier 234. A gas supply pipe 236 is connected to this gas
introduction hole. A gas supply pipe 248a is connected to the gas
supply pipe 236, and a gas supply source 248b, a MFC 248c, a valve
248d, and a heater 248e as a first heating part are installed at
the gas supply pipe 248a sequentially from the upstream side of gas
flow.
[0042] A first gas is supplied from the gas supply source 248b into
the buffer space 233 via the MFC 248c, the valve 248d, the gas
supply pipe 248a, the heater 248e, the gas supply pipe 236, and the
like. The heater 248e is configured to be capable of heating the
first gas, which passes through the heated 248e, to a predetermined
temperature according to an instruction of the controller 280.
Hereinafter, as a matter of convenience, a gas heated in this
manner is also referred to as a heating gas. As the first gas, for
example, at least one selected from the group of an inert gas such
as a nitrogen (N.sub.2) gas and a helium (He) gas and a hydrogen
(H.sub.2) gas may be used. In the embodiments, a case where, for
example, an inert gas is used as the first gas will be
described.
[0043] A first gas supply system 248 mainly includes the gas supply
pipe 248a, the MFC 248c, and the valve 248d. The gas supply source
248b, the heater 248e, and the gas supply pipe 236 may be included
in the first gas supply system 248. The first gas supply system 248
is also referred to as a first gas supply line.
[0044] A temperature measuring part 249 configured to measure the
temperature of the heater 248e is installed at the heater 248e.
Further, a heater controller 250 configured to control the heater
248e is connected to the heater 248e. The heater 248e is controlled
by the controller 280 via the heater controller 250.
[0045] A gas introduction hole configured to supply a gas into the
buffer space 233 at the side wall 234f of the gas supplier 234. A
gas supply pipe 258a is connected to this gas introduction hole. A
gas supply source 258b, a MFC 258c, and a valve 258d are installed
at the gas supply pipe 258a sequentially from the upstream side of
gas flow.
[0046] A third gas is supplied from the gas supply source 258b into
the buffer space 233 via the MFC 258c, the valve 258d, the gas
supply pipe 258a, and the like. As the third gas, for example, at
least one selected from the group of an inert gas such as a N.sub.2
gas or a He gas, a H.sub.2 gas, a diluted H.sub.2 gas, and an
activated H.sub.2 gas may be used. In the embodiments, a case
where, for example, an inert gas is used as the third gas will be
described.
[0047] A third gas supply system 258 mainly includes the gas supply
pipe 258a, the MFC 258c, and the valve 258d. The gas supply source
258b may be included in the third gas supply system 258. The third
gas supply system 258 is also referred to as a third gas supply
line.
[0048] A gas introduction hole configured to supply a gas into the
transfer space 203 is formed at the side surface of the lower
container 2022. A gas supply pipe 256 is connected to this gas
introduction hole. A gas supply pipe 259a is connected to the gas
supply pipe 256. A gas supply source 259b, a MFC 259c, a valve
259d, and a heater 259e as a fourth heating part are installed at
the gas supply pipe 259a sequentially from the upstream side of gas
flow.
[0049] A fourth gas is supplied from the gas supply source 259b
into the transfer space 203 via the MFC 259c, the valve 259d, the
gas supply pipe 259a, the heater 259e, the gas supply pipe 256, and
the like. As the fourth gas, for example, at least one selected
from the group of an inert gas such as a N.sub.2 gas and a He gas,
a H.sub.2 gas, a diluted H.sub.2 gas, and an activated H.sub.2 gas
may be used. In the embodiments, a case where, for example, an
inert gas is used as the fourth gas will be described. The heater
259e is configured to be capable of heating the inert gas, which
passes through the heater 259e, to a predetermined temperature
according to an instruction of the controller 280.
[0050] A fourth gas supply system 259 mainly includes the gas
supply pipe 259a, the MFC 259c, and the valve 259d. The gas supply
source 259b, the heater 259e, and the gas supply pipe 256 may be
included in the fourth gas supply system 259. The fourth gas supply
system 259 is also referred to as a fourth gas supply line.
[0051] An exhauster configured to exhaust an internal atmosphere of
the process container 202 includes a plurality of exhaust pipes
connected to the process container 202. Specifically, the exhauster
includes an exhaust pipe 261 connected to the transfer space 203,
an exhaust pipe 262 connected to the process chamber 201, and an
exhaust pipe 263 connected to the buffer space 233. Further, an
exhaust pipe 264 is connected to each of the downstream ends of the
exhaust pipes 261, 262, and 263.
[0052] An exhaust hole configured to exhaust an internal atmosphere
of the transfer space 203 is formed at the side surface of the
lower container 2022. The exhaust pipe 261 is connected to this
exhaust hole. A TMP (Turbo Molecular Pump) 265, which is a vacuum
pump that realizes a high vacuum or an ultra-high vacuum, is
connected to the exhaust pipe 261. Valves 266 and 267, which are
opening/closing valves, are installed at the upstream side and the
downstream side of the TMP 265 in the exhaust pipe 261,
respectively.
[0053] An exhaust hole configured to exhaust an internal atmosphere
of the process chamber 201 is formed at the side of the process
chamber 201. The exhaust pipe 262 is connected to this exhaust
hole. An APC (Auto Pressure Controller) 276, which is a pressure
controller configured to control the interior of the process
chamber 201 to a predetermined pressure, is installed at the
exhaust pipe 262. The APC 276 includes a valve body whose opening
degree may be adjusted, and is configured to be capable of
adjusting an internal conductance of the exhaust pipe 262 by
adjusting the opening degree of the valve body according to an
instruction from the controller 280. Further, valves 275 and 277,
which are opening/closing valves, are installed at the exhaust pipe
262 on the upstream side and the downstream side of the APC 276
respectively.
[0054] An exhaust hole configured to exhaust an internal atmosphere
of the buffer space 233 is formed at the upper wall 234e of the gas
supplier 234. The exhaust pipe 263 is connected to this exhaust
hole. A TMP 295 is installed at the exhaust pipe 263. Valves 296
and 297, which are opening/closing valves, are installed at the
exhaust pipe 263 on the upstream side and the downstream side of
the TMP 295, respectively.
[0055] ADP (Dry Pump) 278 is connected to the exhaust pipe 264.
More specifically, the exhaust pipes 263, 262, and 261 are
connected to the exhaust pipe 264 at the upstream side thereof, and
the DP 278 is connected to the exhaust pipe 264 at the downstream
side thereof. The DP 278 exhausts the atmospheres of the buffer
space 233, the process chamber 201, and the transfer space 203 via
the exhaust pipes 263, 262, and 261, respectively. The DP 278 also
functions as an auxiliary pump when the TMPs 265 and 295 operate.
That is, since it is difficult for the TMPs 265 and 295, which are
a high vacuum (or ultra-high vacuum) pumps, to perform an exhaust
alone up to the atmospheric pressure, the DP 278 is used as an
auxiliary pump configured to perform the exhaust up to the
atmospheric pressure.
[0056] As shown in FIG. 1, the substrate processing apparatus 100
includes the controller 280 configured to control operations of
various parts of the substrate processing apparatus 100.
[0057] As shown in FIG. 2, the controller 280, which is a
controller (control means), may be configured as a computer
including a CPU (Central Processing Unit) 280a, a RAM (Random
Access Memory) 280b, a memory 280c, and an I/O port 280d. The RAM
280b, the memory 280c, and the I/O port 280d are configured to be
capable of exchanging data with the CPU 280a via an internal bus
280e. An input/output device 289 configured as, for example, a
touch panel and the like or an external memory 288, may be
connected to the controller 280.
[0058] The memory 280c includes, for example, a flash memory, a HDD
(Hard Disk Drive), a SSD (Solid State Drive), or the like. A
control program configured to control operations of the substrate
processing apparatus 100, a process recipe in which sequences,
conditions, and the like of substrate processing to be described
below are written, and the like are readably stored in the memory
280c. The process recipe functions as a program configured to allow
the controller 280 to cause the substrate processing apparatus 100
to execute each sequence in the substrate processing to be
described below, to obtain an expected result. Hereinafter, the
process recipe and the control program may be generally and simply
referred to as a "program." Furthermore, the process recipe may be
simply referred to as a "recipe." When the term "program" is used
herein, it may indicate a case of including the recipe only, a case
of including the control program only, or a case of including both
the recipe and the control program. The RAM 280b is configured as a
memory area (work area) in which a program or data read by the CPU
280a is temporarily stored.
[0059] The I/O port 280d is connected to the gate valve 205, the
transfer mechanism 500, the elevator 218, the APC 276, the TMPs 265
and 295, the DP 278, the RPU 244e, the MFCs 243c, 244c, 245c, 246c,
247c, 248c, 258c, and 259c, the valves 243d, 244d, 245d, 246d,
247d, 248d, 258d, 259d, 266, 267, 275, 277, 296, and 297, the
heaters 213, 248e, and 259e, and the like.
[0060] The CPU 280a is configured to read and execute the control
program from the memory 280c. The CPU 280a is also configured to be
capable of reading the recipe from the memory 280c according to an
input of an operation command from the input/output device 289. The
CPU 280a is configured to control the opening/closing operation of
the gate valve 205, the transferring operation of the wafer 200 by
the transfer mechanism 500, the elevating operation of the
substrate mounting stand 212 by the elevator 218, the adjusting
operation of the internal pressure of the process chamber 201 by
the APC 276, the on/off control of the TMPs 265 and 295, the on/off
control of the DP 278, the on/off control of plasma by the RPU
244e, the flow rate regulating operation of various types of gases
by the MFCs 243c, 244c, 245c, 246c, 247c, 248c, 258c, and 259c, the
opening/closing control of the valves 243d, 244d, 245d, 246d, 247d,
248d, 258d, 259d, 266, 267, 275, 277, 296, and 297, the on/off
control and the temperature regulating operation of the heaters
213, 248e, and 259e, and the like, according to contents of the
read recipe.
[0061] The controller 280 may be configured by installing, on the
computer, the aforementioned program stored in the external memory
288. Examples of the external memory 288 may include a magnetic
disk such as a HDD, an optical disc such as a CD, a magneto-optical
disc such as a MO, a semiconductor memory such as a USB memory or a
SSD, and the like. The memory 280c or the external memory 288 is
configured as a computer-readable recording medium. Hereinafter,
the memory 280c and the external memory 288 may be generally and
simply referred to as a "recording medium." When the term
"recording medium" is used herein, it may indicate a case of
including the memory 280c only, a case of including the external
memory 288 only, or a case of including both the memory 280c and
the external memory 288. Furthermore, the program may be provided
to the computer by using a communication means such as the Internet
or a dedicated line, instead of using the external memory 288.
(2) SUBSTRATE PROCESSING
[0062] As a process of manufacturing a semiconductor device by
using the above-described substrate processing apparatus 100, a
processing sequence of forming a thin film on a wafer 200 as a
substrate in a process container 202 will be described. In the
following description, the operations of various parts constituting
the substrate processing apparatus 100 are controlled by the
controller 280.
[0063] A processing sequence in some embodiments includes:
[0064] a step a of loading the wafer 200 into the process container
202;
[0065] a step b of heating the wafer 200 by supplying a first gas,
which is heated when passing through a heater 248e installed at a
first gas supply system 248, to the wafer 200 via a gas supplier
234;
[0066] a step c of supplying a second gas, which flows through a
second gas supply system different from the first gas supply system
248, to the wafer 200 mounted on a substrate mounting stand 212 in
the process container 202, via the gas supplier 234; and
[0067] a step d of lowering the temperature of the gas supplier 234
by supplying a third gas, which has a temperature lower than that
of the first gas, to the gas supplier 234 between the step b and
the step c.
[0068] The processing sequence in the embodiments further includes,
as an example, before the step c, a step e of holding the wafer 200
in a state of being mounted on the substrate mounting stand 212,
and heating the wafer 200 from a rear surface side by heat
conduction from the substrate mounting stand 212 heated by the
heater 213.
[0069] The processing sequence in the embodiments further includes,
as an example, before the step a, a step f of heating the gas
supplier 234 by radiation (also referred to as emission) from the
substrate mounting stand 212 heated by the heater 213. When the
substrate mounting stand 212 is made of quartz, ceramics, or the
like capable of transmitting light (electromagnetic waves),
radiation from the heater 213 transmits through the substrate
mounting stand 212 and is delivered to the gas supplier 234 such
that the gas supplier 234 may be heated. Therefore, in this case,
the gas supplier 234 is heated by the radiation from the heater
213, the radiation from the substrate mounting stand 212 heated by
the heater 213, and the like.
[0070] The processing sequence in the embodiments further includes,
as an example, between the step a and the step b, a step g of
heating the wafer 200 by supplying a fourth gas, which is heated
when passing through a heater 259e installed at a fourth gas supply
system 259, to the wafer 200 in a state where the wafer 200 is
accommodated in a transfer space 203 installed in the process
container 202.
[0071] The processing sequence in the embodiments further includes,
as an example, after the step c, a step h of cooling the wafer 200
by supplying the third gas to the wafer 200.
[0072] In the following, an example of forming a nitride film as a
film will be described. Here, the nitride film includes not only a
silicon nitride film (SiN film) but also a nitride film containing
carbon (C), oxygen (O), boron (B), or the like. That is, the
nitride film includes a silicon nitride film (SiN film), a silicon
carbonitride film (SiCN film), a silicon oxynitride film (SiON
film), a silicon oxycarbonitride film (SiOCN film), a silicon
borocarbonitride film (SiBCN film).), a silicon boronitride film
(SiBN film), a silicon oxyborocarbonitride film (SiBOCN film), a
silicon oxyboronitride film (SiBON film), and the like.
Hereinafter, an example of forming a SiN film as a nitride film
will be described.
[0073] In the following, as described above, each of the precursor
gas and the reaction gas may be referred to as the second gas.
Further, in the following, in the step b, an example of performing
a cycle a predetermined number of times (m times, where m is an
integer of 1 or more), the cycle including a step of supplying the
precursor gas to the wafer 200 and a step of supplying the reaction
gas to the wafer 200, will be described. The step of supplying the
precursor gas and the step of supplying the reaction gas may be
performed alternately, that is, non-simultaneously, or these steps
may be performed simultaneously. In the following, an example of
performing these steps alternately will be described. In the
present disclosure, as a matter of convenience, such a gas supply
sequence may be represented as follows. The same notation is used
in other embodiments, modifications, and the like to be described
below.
(Precursor gas.fwdarw.reaction gas).times.m
[0074] When the term "wafer" is used in the present disclosure, it
may refer to "a wafer itself" or "a laminated body of a wafer and
certain layers or films formed on a surface of the wafer." When the
phrase "a surface of a wafer" is used in the present disclosure, it
may refer to "a surface of a wafer itself" or "a surface of a
certain layer and the like formed on a wafer." When the expression
"a certain layer is formed on a wafer" is used in the present
disclosure, it may mean that "a certain layer is formed directly on
a surface of a wafer itself" or that "a certain layer is formed on
a layer and the like formed on a wafer." When the term "substrate"
is used in the present disclosure, it is synonymous with the term
"wafer."
(Gas Supplier Heating Step: Step f)
[0075] The heaters 213, 248e, and 259e are turned on, and heating
and temperature control of an object by the heaters 213, 248e, and
259e are started. Here, set temperatures of the heaters 248e and
259e are set to a temperature in the range of, for example, 50 to
500 degrees C., specifically 100 to 400 degrees C. Further, the set
temperature of the heater 213 is set to a temperature in the range
of, for example, 10 to 500 degrees C., specifically 20 to 300
degrees C. After the temperatures of the heaters 213, 248e, and
259e are stabilized, the substrate mounting stand 212 is lowered to
the transfer position (wafer transfer position) of the wafer 200,
and the lift pins 207 are passed through the through-holes 214 of
the substrate mounting stand 212. In parallel with this operation,
the internal atmosphere of the transfer space 203 is exhausted such
that the internal pressure of the transfer space 203 becomes equal
to or lower than the internal pressure of the transfer chamber 600.
At this time, the gas supplier 234 is in a state of being heated
from below by radiation from the heater 213, radiation from the
substrate mounting stand 212 heated by the heater 213, and the
like. Since the gas supplier 234 has a large heat capacity and
therefore it takes time for the gas supplier 234 to be heated, the
gas supplier 234 may be pre-heated in this way before the step a to
be described below. Further, in the step f, raised temperatures of
the heaters 213, 248e, and 259e are maintained in each step to be
described below. Further, a distance between the gas supplier 234
and the substrate mounting stand 212 in the step f may be smaller
(shorter) than a distance between the gas supplier 234 and the
substrate mounting stand 212 in the step c to be described below.
When the distance between the gas supplier 234 and the substrate
mounting stand 212 is shortened, a structure is configured such
that an outer peripheral side of the substrate mounting stand 212
shown in FIG. 1 and members in the process container 202 do not
come into contact with each other. Further, in the step f, the
inert gas, the first gas, and the fourth gas may be supplied from
the gas supply system 245, the first gas supply system 248, and the
fourth gas supply system 259 into the process chamber 201 and the
transfer space 203, respectively. Further, in the step f, the
heaters 248e or the heater 259e may be turned off. For example, the
heater 248e is turned on and the heater 259e is turned off.
(Substrate Loading Step: Step a)
[0076] Subsequently, the gate valve 205 is opened such that the
interior of the transfer space 203 is in fluid communication with
the interior of the transfer chamber 600. Then, the wafer 200 is
loaded from the transfer chamber 600 into the transfer space 203 by
using the transfer mechanism 500 installed in the transfer chamber
600.
(Substrate Heating Step: Step g)
[0077] Then, the inert gas, the first gas, and the fourth gas are
supplied from the gas supply system 245, the first gas supply
system 248, and the fourth gas supply system 259 into the process
chamber 201 and the transfer space 203, respectively. In parallel
with this, the internal atmospheres of the process chamber 201 and
the transfer space 203 are exhausted via the exhaust pipe 261. The
first gas and the fourth gas supplied from the first gas supply
system 248 and the fourth gas supply system 259 are heated by the
heaters 248e and 259e, supplied into the process chamber 201 and
the transfer space 203, respectively, and are exhausted via the
exhaust pipe 261. At this time, the heated first gas and fourth gas
are supplied to the wafer 200 in the transfer space 203, and these
gases come into contact with the wafer 200. In this way, the wafer
200 in the transfer space 203 is heated (pre-heated). Here, set
temperatures of the heaters 248e and 259e when heating the wafer
200 are set to a temperature in the range of, for example, 50 to
500 degrees C., specifically 100 to 400 degrees C. in some
embodiments. The step g may not be performed and may be omitted.
For example, when it is desired to shorten a time needed to heat
(pre-heat) the wafer 200, the step g may be performed before the
step b. Further, a supply amount (supply flow rate) of the inert
gas from the gas supply system 245 may be a supply amount (supply
flow rate) by which other gases may be prevented from penetrating
from the process chamber 201 into the gas supply system 245.
(Substrate Heating/Substrate Radiation Heating Step: Step b)
[0078] The wafer 200 can be placed on the lift pins 207 by loading
the wafer 200 into the transfer space 203 by the transfer mechanism
500, holding the wafer 200 over the lift pins 207, and then
lowering the transfer mechanism 500 to mount the wafer 200 on the
lift pins 207. Then, the transfer mechanism 500 is moved out of the
transfer space 203, and the substrate loading/unloading port 206 is
closed by the gate valve 205. As a result, the wafer 200 may be
held on the lift pins 207 in the transfer space 203.
[0079] In the step b, the supply of the inert gas from the gas
supply system 245 is continued following the step g. However, after
the substrate loading/unloading port 206 is closed by the gate
valve 205, the supply of the inert gas from the gas supply system
245 is stopped.
[0080] Further, in the step b, following the step g, the supply of
the first gas and the supply of the fourth gas from the first gas
supply system 248 and the fourth gas supply system 259 to the wafer
200 in the transfer space 203 are continued, respectively. Further,
the exhaust of the internal atmospheres of the process chamber 201
and the transfer space 203 from the exhaust pipe 261 are
continued.
[0081] Specifically, in the step b, the valves 248d and 259d are
maintained in the opened state, such that the first gas and the
fourth gas flow through the gas supply pipes 248a and 259a,
respectively. Flow rates of the first gas and the fourth gas are
regulated by the MFCs 248c and 259c, and the first gas and the
fourth gas are heated by the heaters 248e and 259e, respectively.
Then, the first gas and the fourth gas are supplied into the
process chamber 201 and the transfer space 203 via the gas supply
pipes 236 and 256, respectively, and are exhausted via the exhaust
pipe 261. At this time, the heated first gas and fourth gas are
supplied to the wafer 200 in the transfer space 203, and these
gases come into contact with the wafer 200. In this way, the wafer
200 in the transfer space 203 is heated. Here, the set temperatures
of the heaters 248e and 259e when heating the wafer 200 is set to a
temperature in the range of, for example, 50 to 500 degrees C.,
specifically 100 to 400 degrees C.
[0082] Processing conditions in the step b are exemplified as
follows.
[0083] Processing temperature: 10 to 500 degrees C., specifically
20 to 300 degrees C. in some embodiments
[0084] Processing pressure: 10 to 13,333 Pa, specifically 100 to
10,000 Pa in some embodiments
[0085] First gas supply flow rate: 0.0001 to 100 slm, specifically
0.001 to 10 slm in some embodiments
[0086] First gas supply time: 1 to 300 seconds, specifically 5 to
60 seconds in some embodiments
[0087] Fourth gas supply flow rate: 0.0001 to 100 slm, specifically
0.001 to 5 slm in some embodiments
[0088] Fourth gas supply time: 0.1 to 300 seconds, specifically 5
to 60 seconds in some embodiments
[0089] Inert gas supply flow rate: 0.0001 to 100 slm, specifically
0.001 to 5 slm in some embodiments
[0090] Inert gas supply time: 0.1 to 150 seconds, specifically 2 to
30 seconds in some embodiments
[0091] The processing temperature shown here means the temperature
of the wafer 200, that is, a pre-heating target temperature of the
wafer 200.
[0092] The notation of a numerical range such as "10 to 500 degrees
C." in the present disclosure means that a lower limit value and an
upper limit value are included in the numerical range. Therefore,
for example, "10 to 500 degrees C." means "10 degrees C. or higher
and 500 degrees C. or lower." The same applies to other numerical
ranges. Further, in the present disclosure, the processing
temperature means the temperature of the wafer 200 or the internal
temperature of the process chamber 201, and the processing pressure
means the internal pressure of the process chamber 201. Further,
the gas supply flow rate of 0 slm means a case where no gas is
supplied. The same applies to the following description.
[0093] Examples of the first gas, the fourth gas, and the inert gas
may include rare gases such as a nitrogen (N.sub.2) gas, an argon
(Ar) gas, a helium (He) gas, a neon (Ne) gas, and a xenon (Xe) gas.
One or more of these gases may be used as the first gas, the fourth
gas, and the inert gas. The type of gas when the inert gas is used
in each of the other steps may be the same as the type of gas
described here.
[0094] The first gas supplied from the first gas supply system 248
in the step b is heated by the heater 248e, supplied to the wafer
200 via the buffer space 233 (the gas supplier 234), and comes into
contact with the surface of the wafer 200. In this way, the wafer
200 is heated from above (front surface side). Further, since the
wafer 200 is mounted on the lift pins 207 and is held in a floating
state without being mounted on the substrate mounting stand 212, it
is heated by radiation from the heater 213 included in the
substrate mounting stand 212, radiation from the substrate mounting
stand 212 heated by the heater 213, and the like. In this way, the
wafer 200 is also heated from below (rear surface side). Further,
since the wafer 200 is mounted on the lift pins 207, the fourth gas
supplied from the fourth gas supply system 259 and heated by the
heater 259e also infiltrates a space between the wafer 200 and the
substrate mounting stand 212 and comes into contact with the rear
surface of the wafer 200. In this way, the wafer 200 is further
heated from below (rear surface side). As a result, the wafer 200
is heated from both the front and rear sides. Further, at this
time, the gas supplier 234 is also heated from below by radiation
from the heater 213, radiation from the substrate mounting stand
212 heated by the heater 213, radiation from the heated wafer 200,
and the like.
(Substrate Heat Conduction Heating Step: Step e)
[0095] Subsequently, the substrate mounting stand 212 is raised,
the wafer 200 mounted on the lift pins 207 is picked up by the
substrate mounting stand 212, the wafer 200 is mounted on the
substrate mounting surface 211, and the substrate mounting stand
212 is raised to the processing position of the wafer 200 (wafer
processing position) shown in the figure. At least until the wafer
200 moves from the wafer transfer position to the wafer processing
position, the supply of the heated first gas from the first gas
supply system 248 is continuously maintained, and the wafer 200 is
heated from above (front surface side). At this time, the supply of
the heated fourth gas from the fourth gas supply system 259 is also
maintained. Further, at this time, since the wafer 200 is mounted
on the substrate mounting surface 211, the wafer 200 is heated from
below (rear surface side) by heat conduction from the substrate
mounting stand 212 heated by the heater 213.
(Gas Supplier Cooling Step: Step d)
[0096] After performing the step b and before performing the step c
(film-forming process) to be described below, the third gas having
a temperature lower than that of the first gas is supplied from the
third gas supply system 258 into the buffer space 233.
[0097] Specifically, the valve 258d is opened to allow the third
gas to flow through the gas supply pipe 258a. A flow rate of the
third gas is regulated by the MFC 258c, and the third gas is
supplied into the buffer space 233 and then is exhausted via the
exhaust pipe 263. At this time, the third gas diffuses in the
buffer space 233, and the third gas diffused in the buffer space
233 comes into contact with the upper wall 234e and the side wall
234f constituting the buffer space 233.
[0098] Processing conditions in the step b are exemplified as
follows.
[0099] Processing temperature: 50 to 1,000 degrees C., specifically
300 to 600 degrees C. in some embodiments
[0100] Processing pressure: 10 to 13,333 Pa, specifically 20 to
1,000 Pa in some embodiments
[0101] Third gas supply flow rate: 0.0001 to 100 slm, specifically
0.001 to 10 slm in some embodiments
[0102] Third gas supply time: 0.1 to 300 seconds, specifically 1 to
60 seconds in some embodiments
[0103] The processing temperature here means the temperature of the
wafer 200, that is, the temperature of the wafer 200 when the step
d is performed after going through the step g, the step b, and the
step e, and may be a temperature close to the processing
temperature in the step c (film-forming process) to be described
below or the same temperature as in the step c.
[0104] The temperature of the gas supplier 234 may be lowered by
supplying the third gas having the temperature lower than that of
the first gas into the buffer space 233 under the aforementioned
processing conditions. As a result, in the step c (film-forming
process) to be described below, it is possible to prevent the
second gas from being excessively heated by the gas supplier 234 to
cause unexpected decomposition or the like. Here, the temperature
of the gas supplier 234 is lowered to fall within a temperature
range such that the characteristics of the second gas do not change
significantly. The lower limit of the temperature range may be a
temperature at which aggregation, liquefaction (solidification),
and the like of the second gas are unlikely to occur. The upper
limit of the temperature range may be a temperature at which
decomposition of the second gas is unlikely to occur. For example,
in the step d, the gas supplier 234 may be cooled to a temperature
within the range of 100 to 600 degrees C., specifically 200 to 400
degrees C. By cooling the gas supplier 234 to such a temperature,
it is possible to prevent the characteristics (reactivity) of the
second gas from changing greatly due to unexpected decomposition,
aggregation, liquefaction (solidification), and the like.
[0105] Further, in the step d, in parallel with the supply of the
third gas into the buffer space 233, the internal atmosphere of the
buffer space 233 may be exhausted via the exhaust pipe 263 in some
embodiments. As a result, it is possible to avoid the third gas of
low temperature from being supplied to the pre-heated wafer 200,
thereby preventing the temperature of the pre-heated wafer 200 from
being lowered.
(Film-Forming Process: Step c)
[0106] Then, as the step c, the following steps c1 and c2 are
sequentially performed.
[Step c1]
[0107] In a step c1, the precursor gas as the second gas is
supplied to the wafer 200 in the process chamber 201.
[0108] Specifically, the valve 243d is opened to allow the
precursor gas to flow through the gas supply pipe 243a. A flow rate
of the precursor gas is regulated by the MFC 243c, and the
precursor gas is supplied into the process chamber 201 via the
common gas supply pipe 242, the gas supply pipe 241, the shower
head buffer chamber 232, and the gas supplier 234 (the
through-holes 234b) and is exhausted via the exhaust pipe 262. In
this operation, the precursor gas is supplied to the wafer 200
(precursor gas supply). At this time, the valves 246d and 247d may
be opened to allow an inert gas to be supplied from each of the gas
supply pipes 246a and 247a into the process chamber 201.
[0109] Processing conditions in the step c1 are exemplified as
follows.
[0110] Processing temperature: 50 to 1,000 degrees C., specifically
300 to 800 degrees C. in some embodiments
[0111] Processing pressure: 10 to 1,000 Pa, specifically 20 to 100
Pa in some embodiments
[0112] Precursor gas supply flow rate: 0.0001 to 100 slm,
specifically 0.001 to 10 slm in some embodiments
[0113] Precursor gas supply time: 0.1 to 120 seconds, specifically
1 to 60 seconds, more specifically 1 to 30 seconds in some
embodiments
[0114] Inert gas supply flow rate (for each gas supply pipe): 0 to
100 slm, specifically 0.0001 to 20 slm, more specifically 0.01 to
10 slm in some embodiments
[0115] By supplying the precursor gas, for example, a
chlorosilane-based gas, to the wafer 200 under the aforementioned
processing conditions, a Si-containing layer containing Cl is
formed on the outermost surface of the wafer 200 as a base. The
Si-containing layer containing Cl is formed by physical adsorption
or chemical adsorption of molecules of the chlorosilane-based gas,
physical adsorption or chemical adsorption of molecules of a
substance obtained by partially decomposing the chlorosilane-based
gas, deposition of Si due to thermal decomposition of the
chlorosilane-based gas, and the like on the outermost surface of
the wafer 200. The Si-containing layer containing Cl may be an
adsorption layer (physical adsorption layer or chemical adsorption
layer) of molecules of the chlorosilane-based gas or molecules of a
substance obtained by partially decomposing the chlorosilane-based
gas or may be a deposition layer of Si containing Cl. In the
present disclosure, the Si-containing layer containing Cl is also
simply referred to as a Si-containing layer.
[0116] After the Si-containing layer is formed, the valve 243d is
closed to stop the supply of the precursor gas into the process
chamber 201. Then, the interior of the process chamber 201 is
vacuum-exhausted to remove a gas or the like remaining in the
process chamber 201 from the process chamber 201 (purge). At this
time, the valve 245d may be opened to allow an inert gas to be
supplied into the process chamber 201. When the inert gas is
supplied into the process chamber 201, the inert gas acts as a
purge gas.
[0117] An example of the precursor gas may include a silane-based
gas containing silicon (Si) as a main element constituting a film
formed on the wafer 200. An example of the silane-based gas may
include a gas containing Si and halogen, that is, a
halosilane-based gas. Halogen includes chlorine (Cl), fluorine (F),
bromine (Br), iodine (I), and the like. An example of the
halosilane-based gas may include the aforementioned
chlorosilane-based gas containing Si and Cl.
[0118] Examples of the precursor gas may include chlorosilane-based
gases such as a monochlorosilane (SiH.sub.3Cl, abbreviation: MCS)
gas, a dichlorosilane (SiH.sub.2Cl.sub.2, abbreviation: DCS) gas, a
trichlorosilane (SiHCl.sub.3, abbreviation: TCS) gas, a
tetrachlorosilane (SiCl.sub.4, abbreviation: STC) gas, a
hexachlorodisilane (Si.sub.2Cl.sub.6, abbreviation: HCDS) gas, and
an octachlorotrisilane (Si.sub.3Cl.sub.8, abbreviation: OCTS) gas.
One or more of these gases may be used as the precursor gas.
[0119] Examples of the precursor gas may include fluorosilane-based
gases such as a tetrafluorosilane (SiF.sub.4) gas and a
difluorosilane (SiH.sub.2F.sub.2) gas, bromosilane-based gases such
as a tetrabromosilane (SiBr.sub.4) gas and a dibromosilane
(SiH.sub.2Br.sub.2) gas, and iodosilane-based gases such as a
tetraiodosilane (SiI.sub.4) gas and a diiodosilane
(SiH.sub.2I.sub.2) gas, in addition to the chlorosilane-based gas.
One or more of these gases may be used as the precursor gas.
[0120] In addition to the aforementioned gases, an example of the
precursor gas may include a gas containing Si and an amino group,
that is, an aminosilane-based gas. The amino group is a monovalent
functional group obtained by removing hydrogen (H) from ammonia,
primary amine or secondary amine and may be expressed as
--NH.sub.2, --NHR, or --NR.sub.2. Further, R represents an alkyl
group, and two R's of --NR.sub.2 may be the same or different.
[0121] Examples of the precursor gas may include aminosilane-based
gases such as a tetrakis(dimethylamino)silane
(Si[N(CH.sub.3).sub.2].sub.4, abbreviation: 4 DMAS) gas, a
tris(dimethylamino)silane (Si[N(CH.sub.3).sub.2].sub.3H,
abbreviation: 3 DMAS) gas, a bis(diethylamino)silane
(Si[N(C.sub.2H.sub.5).sub.2].sub.2H.sub.2, abbreviation: BDEAS)
gas, a bis(tert-butylamino)silane
(SiH.sub.2[NH(C.sub.4H.sub.9)].sub.2, abbreviation: BTBAS) gas, and
a (diisopropylamino)silane (SiH.sub.3[N(C.sub.3H.sub.7).sub.2],
abbreviation: DIPAS) gas. One or more of these gases may be used as
the precursor gas.
[Step c2]
[0122] After the step c1 is completed, the reaction gas as the
second gas is supplied to the wafer 200 in the process chamber 201,
that is, the Si-containing layer formed on the wafer 200.
[0123] Specifically, the valve 244d is opened to allow the reaction
gas to flow through the gas supply pipe 244a. A flow rate of the
reaction gas is regulated by the MFC 244c, and the reaction gas is
supplied into the process chamber 201 via the common gas supply
pipe 242, the gas supply pipe 241, the shower head buffer chamber
232, and the gas supplier 234 (the through-holes 234b) and is
exhausted via the exhaust pipe 262. In this operation, the reaction
gas is supplied to the wafer 200 (reaction gas supply). At this
time, the valves 246d and 247d may be opened to allow an inert gas
to be supplied from each of the gas supply pipes 246a and 247a into
the process chamber 201. At this time, the reaction gas may be
supplied after being excited into a plasma state by the RPU 244e.
In this case, the reaction gas excited into the plasma state by the
RPU 244e is supplied to the wafer 200 in the process chamber 201
via the common gas supply pipe 242, the gas supply pipe 241, the
shower head buffer chamber 232, and the gas supplier 234 (the
through-holes 234b).
[0124] Processing conditions in the step c2 are exemplified as
follows.
[0125] Processing temperature: 50 to 1,000 degrees C., specifically
300 to 800 degrees C. in some embodiments
[0126] Processing pressure: 10 to 3,000 Pa, specifically 20 to
1,000 Pa in some embodiments
[0127] Reaction gas supply flow rate: 0.0001 to 100 slm,
specifically 0.001 to 10 slm in some embodiments
[0128] Reaction gas supply time: 0.1 to 120 seconds, specifically 1
to 60 seconds, more specifically 1 to 30 seconds in some
embodiments
[0129] High-frequency power (plasma power): 10 to 1,000 W
[0130] High frequency: 400 KHz to 60 MHz
[0131] Other processing conditions may be the same as those of
processing conditions as in the step c1. The high-frequency power
and the high frequency are conditions under which plasma is
generated when the reaction gas is supplied with being excited into
the plasma state by the RPU 244e.
[0132] By supplying the reaction gas, for example, a nitrogen (N)-
and hydrogen (H)-containing gas, to the wafer 200 under the
aforementioned processing conditions, at least a portion of the
Si-containing layer formed on the wafer 200 is nitrided (modified).
As a result, a silicon nitride layer (SiN layer) is formed as a
layer containing Si and N on the outermost surface of the wafer 200
as a base. When the SiN layer is formed, impurities such as Cl
contained in the Si-containing layer form a gaseous substance
containing at least Cl during modification reaction of the
Si-containing layer by using the N- and H-containing gas, and
discharged from the inside of the process chamber 201. As a result,
the SiN layer becomes a layer having fewer impurities such as Cl
than those of the Si-containing layer formed in the step c1.
[0133] After the SiN layer is formed, the valve 244d is closed to
stop the supply of the reaction gas into the process chamber 201.
Then, a gas or the like remaining in the process chamber 201 is
removed from the inside of the process chamber 201 (purge)
according to the same processing procedure as the purge in the step
c1.
[0134] An example of the reaction gas may include a nitriding gas
(nitriding agent or nitrogen source). An example of the nitriding
gas may include the aforementioned N- and H-containing gas. The N-
and H-containing gas is both a N-containing gas and a H-containing
gas. The N- and H-containing gas may contain a N--H bond in some
embodiments.
[0135] Examples of the reaction gas may include hydrogen
nitride-based gases such as an ammonia (NH.sub.3) gas, a diazene
(N.sub.2H.sub.2) gas, a hydrazine (N.sub.2H.sub.4) gas, and a
N.sub.3H.sub.8 gas. One or more of these gases may be used as the
reaction gas.
[0136] In addition to the aforementioned gases, an example of the
reaction gas may include a nitrogen (N)-, carbon (C)-, and hydrogen
(H)-containing gas. Examples of the N-, C-, and H-containing gas
may include an amine-based gas and an organic hydrazine-based gas.
The N-, C-, and H-containing gas is a N-containing gas, a
C-containing gas, and a H-containing gas. Further, the N-, C-, and
H-containing gas is a N- and C-containing gas, a N- and
H-containing gas, and a C- and H-containing gas.
[0137] Examples of the reaction gas may include ethylamine-based
gases such as a monoethylamine (C.sub.2H.sub.5NH.sub.2,
abbreviation: MEA) gas, a diethylamine ((C.sub.2H.sub.5).sub.2NH,
abbreviation: DEA) gas, and a triethylamine
((C.sub.2H.sub.5).sub.3N, abbreviation: TEA) gas, methylamine-based
gas such as a monomethylamine (CH.sub.3NH.sub.2, abbreviation: MMA)
gas, a dimethylamine ((CH.sub.3).sub.2NH, abbreviation: DMA) gas,
and a trimethylamine ((CH.sub.3).sub.3N, abbreviation: TMA) gas,
organic hydrazine-based gases such as a monomethylhydrazine
((CH.sub.3)HN.sub.2H.sub.2, abbreviation: MMH) gas, a
dimethylhydrazine ((CH.sub.3).sub.2N.sub.2H.sub.2, abbreviation:
DMH) gas, and a trimethylhydrazine
((CH.sub.3).sub.2N.sub.2(CH.sub.3)H, abbreviation: TMH) gas, and
the like. One or more of these gases may be used as the reaction
gas.
[Performing Cycle Predetermined Number of Times]
[0138] By performing a cycle a predetermined number of times (m
times, where m is an integer of 1 or more), the cycle including
non-simultaneously, that is, without synchronization, preforming
the aforementioned steps c1 and c2, a film having a predetermined
thickness, for example, a SiN film having a predetermined
thickness, may be formed on the surface of the wafer 200 as a base.
The above cycle may be performed a plurality of times in some
embodiments. That is, a thickness of the SiN layer formed per cycle
is made thinner than a desired film thickness, and the
aforementioned cycle may be performed a plurality of times until a
film thickness of a SiN film formed by laminating the SiN layers
reaches the desired film thickness in some embodiments. When the
N-, C-, and H-containing gas is used as the reaction gas, for
example, a silicon carbonitride layer (SiCN layer) may be formed by
the aforementioned cycle, and a film, for example, a silicon
carbonitride film (SiCN film), may be formed on the surface of the
wafer 200 by performing the aforementioned cycle a predetermined
number of times.
(After-Purge)
[0139] After the process of forming the SiN film having the desired
thickness on the wafer 200 is completed, an inert gas as a purge
gas is supplied into the process chamber 201 from each of the gas
supply pipes 246a, 247a, and 245a and is exhausted via the exhaust
pipe 262. As a result, the interior of the process chamber 201 is
purged to remove a gas, reaction by-products, and the like
remaining in the process chamber 201 from the inside of the process
chamber 201 (after-purge). Then, the internal atmosphere of the
process chamber 201 is substituted with the inert gas (inert gas
substitution).
(Substrate Cooling Step: Step h)
[0140] Subsequently, the third gas is supplied from the third gas
supply system 258 into the buffer space 233.
[0141] Specifically, the valve 258d is opened to allow the third
gas to flow through the gas supply pipe 258a. A flow rate of the
third gas is regulated by the MFC 258c, and the third gas is
supplied into the buffer space 233 and is then supplied to the
processed wafer 200 via the through-holes 234a and the process
chamber 201.
[0142] Processing conditions in the step h are exemplified as
follows.
[0143] Processing temperature: 50 to 650 degrees C., specifically
20 to 300 degrees C. in some embodiments
[0144] Processing pressure: 10 to 13,333 Pa, specifically 100 to
10,000 Pa in some embodiments
[0145] Third gas supply flow rate: 0.0001 to 100 slm, specifically
0.001 to 10 slm in some embodiments
[0146] Third gas supply time: 0.1 to 300 seconds, specifically 1 to
60 seconds in some embodiments
[0147] By supplying the third gas to the processed wafer 200 under
the aforementioned processing conditions, the processed wafer 200
may be cooled in the process container 202, that is, in the process
chamber 201.
[0148] Further, in the step h, the processed wafer 200 may be
cooled in a state where the substrate mounting stand 212 is lowered
to mount the processed wafer 200 on the lift pins 207 such that the
processed wafer 200 and the substrate mounting stand 212 are
separated from each other. For example, in the step h, the
processed wafer 200 may be cooled in a state where the substrate
mounting stand 212 is lowered to the wafer transfer position.
Further, for example, in the step h, the processed wafer 200 may be
cooled in a state where the substrate mounting stand 212 is held at
a position at which the processed wafer 200 and the substrate
mounting stand 212 may be separated from each other, between the
wafer processing position and the wafer transfer position. In this
case, by separating the processed wafer 200 and the substrate
mounting stand 212 from each other, heat conduction from the
substrate mounting stand 212 heated by the heater 213 to the
processed wafer 200 may be blocked, whereby it possible to further
improve a cooling efficiency of the wafer 200.
(Substrate Unloading Step)
[0149] Subsequently, the substrate mounting stand 212 is lowered to
the wafer transfer position, the processed wafer 200 is delivered
from the substrate mounting stand 212 to the lift pins 207, and the
processed wafer 200 is mounted on the lift pins 207. As a result,
the processed wafer 200 may be held on the lift pins 207 in the
transfer space 203. When the substrate mounting stand 212 is
lowered to the wafer transfer position in the step h, this
operation is performed in the step h. After the internal pressures
of the process chamber 201 and the transfer space 203 are regulated
to a predetermined pressure, the gate valve 205 is opened. Then,
the processed wafer 200 mounted on the lift pins 207 is unloaded
out of the transfer space 203 by the transfer mechanism 500 in the
transfer space 203. That is, the processed wafer 200 is transferred
from the inside of the transfer space 203 into the transfer chamber
600 by the transfer mechanism 500.
(3) EFFECTS OF THE PRESENT EMBODIMENT
[0150] According to the embodiments, one or more effects set forth
below may be achieved.
[0151] (a) By performing the step d of lowering the temperature of
the gas supplier 234 by supplying the third gas having the
temperature lower than that of the heated first gas to the gas
supplier 234 between the step b and the step c, it is possible to
cool the gas supplier 234 heated in the step b, thereby preventing
the second gas supplied in the step c from being excessively heated
by the gas supplier 234. As a result, in the step c, it is possible
to prevent unexpected decomposition and the like from occurring due
to a change in reaction characteristics of the second gas, which
makes it possible to improve a process uniformity for each
wafer.
[0152] In the step b, by pre-heating the wafer 200 before the step
c, it is possible to shorten the time taken until the temperature
of the wafer 200 reaches the processing temperature in the step c.
As a result, it is possible to shorten the processing time, thereby
increasing a throughput and hence improving a productivity.
[0153] (b) In the step b, by heating the wafer 200 from both the
front and rear sides, it is possible to increase a temperature rise
rate of the wafer 200, which makes it possible to shorten the
pre-heating time of the wafer 200. Further, by heating the wafer
200 from both the front and rear surfaces, it is possible to reduce
a temperature difference between the front surface and the rear
surface of the wafer 200, which make it possible to prevent the
wafer 200 from warping due to the temperature difference between
the front surface and the rear surface of the wafer 200.
[0154] In the step b, in a state where the wafer 200 is held on the
lift pins 207, by heating the wafer 200 from the rear surface side
by radiation from the heater 213 installed at the substrate
mounting stand 212, radiation from the substrate mounting stand 212
heated by the heater 213, and the like, it is possible to prevent a
rapid temperature rise on the rear surface side of the wafer 200,
whereby it possible to reduce the temperature difference between
the front surface and the rear surface of the wafer 200. As a
result, it is possible to prevent the wafer 200 from warping due to
the temperature difference between the front surface and the rear
surface of the wafer 200, that is, the temperature on the rear
surface side being higher than the temperature on the front surface
side of the wafer 200.
[0155] By performing the step b in a state where the wafer 200 is
held on the lift pins 207, since the temperature difference between
the front surface and the rear surface of the wafer 200 may be
regulated to be small, it is possible to prevent the wafer 200 from
warping due to the temperature difference between the front surface
and the rear surface of the wafer 200. Specifically, in the step b,
for example, by raising or lowering the substrate mounting stand
212 with respect to the fixed lift pins 207 by using the elevator
218, it is possible to regulate a positional relationship between
the wafer 200 on the lift pins 207 and the substrate mounting stand
212 (the heater 213), that is, a distance between the wafer 200 and
the substrate mounting stand 212. As a result, it is possible to
finely regulate the temperature on the rear surface side of the
wafer 200, whereby it possible to finely control a temperature
balance between the front surface and the rear surface of the wafer
200.
[0156] (c) Before the step c, by holding the wafer 200 in a state
where the wafer 200 is mounted on the substrate mounting stand 212
and performing the step e of heating the wafer 200 from the rear
surface side by the heat conduction from the substrate mounting
stand 212 heated by the heater 213, it is possible to directly heat
the wafer 200, which makes it possible to further shorten the
pre-heating time.
[0157] (d) In the step b, by heating the gas supplier 234 by
radiation from the heater 213 installed at the substrate mounting
stand 212, radiation from the substrate mounting stand 212 heated
by the heater 213, radiation from the heated wafer 200, and the
like, it is possible to prevent deterioration of film
characteristics of a film formed on the wafer 200 and interface
characteristics at an interface between the film and the wafer 200
in the step c. Specifically, for example, in the step b, when the
wafer 200 is heated, a gas (for example, a H.sub.2O gas) desorbed
from the wafer 200 may be adsorbed on the gas supplier 234. In this
case, in the step c, this gas may be desorbed from the gas supplier
234 and may be supplied to the wafer 200, which causes
deterioration of the film characteristics of the film formed on the
wafer 200 and the interface characteristics at an interface between
the film and the wafer 200. Further, a gas desorbed from the gas
supplier 234 at the initial stage of the step c affects the
interface characteristics at the interface between the wafer 200
and the film formed on the wafer 200, and a gas desorbed from the
gas supplier 234 after the initial stage of the step c affects the
film characteristics of the film formed on the wafer 200. By
heating the gas supplier 234 as described above in the step b, it
is possible to prevent the gas desorbed from the wafer 200 from
being adsorbed on the gas supplier 234, whereby it possible to
prevent the deterioration of the aforementioned film
characteristics and interface characteristics.
[0158] Further, in the step b, the gas supplier 234 may be heated
by the first gas supplied from the first gas supply system 248 and
heated by the heater 248e, whereby in the step c, it is possible to
further prevent the deterioration of the film characteristics of
the film formed on the wafer 200 and the interface characteristics
at the interface between the film and the wafer 200. That is, by
heating the gas supplier 234 as described above in the step b, it
is possible to prevent the gas desorbed from the wafer 200 from
being adsorbed on the gas supplier 234, which makes it possible to
prevent the deterioration of the aforementioned film
characteristics and interface characteristics.
[0159] (e) Before the step a, by performing the step f of heating
the gas supplier 234 by radiation from the heater 213 installed at
the substrate mounting stand 212, radiation from the substrate
mounting stand 212 heated by the heater 213, and the like, the gas
supplier 234 may be heated in advance, and it possible to prevent a
gas desorbed from the wafer 200 due to the heating of the wafer 200
at the initial stage of the step b from being adsorbed on the gas
supplier 234.
[0160] In addition, in the step f, the gas supplier 234 may be
heated by the first gas supplied from the first gas supply system
248 and heated by the heater 248e, and furthermore, the gas
supplier 234 may also be heated by the fourth gas supplied from the
fourth gas supply system 259 and heated by the heater 259e.
Therefore, it is possible to prevent the gas desorbed from the
wafer 200 due to the heating of the wafer 200 at the initial stage
of the step b from being adsorbed on the gas supplier 234.
[0161] (f) The distance (distance A) between the gas supplier 234
and the substrate mounting stand 212 in the step f may be made
smaller (shorter) than the distance (distance B) between the gas
supplier 234 and the substrate mounting stand 212 in the step c,
whereby the heating time of the gas supplier 234 may be shortened.
That is, by making the distance A shorter than the distance B, the
heating efficiency of the gas supplier 234 due to the radiation
from the heater 213 in the substrate mounting stand 212, the
radiation from the substrate mounting stand 212 heated by the
heater 213, and the like may be improved, whereby it possible to
shorten a temperature rise time of the gas supplier 234. Further,
in the step f, since the substrate mounting stand 212 is maintained
in a state of being heated by the heater 213, it is possible to
prevent the temperature of the substrate mounting stand 212 from
changing suddenly even when the heat of the substrate mounting
stand 212 is taken away by the gas supplier 234.
[0162] (g) In the step d, by supplying the third gas to the gas
supplier 234 from the third gas supply system 258 different from
the first gas supply system 248, the third gas unheated may be
efficiently supplied to the gas supplier 234, whereby it possible
to shorten the cooling time of the gas supplier 234.
[0163] (h) In the step d, by supplying the third gas to the gas
supplier 234 without going through the first gas supply system 248,
the third gas unheated may be efficiently supplied to the gas
supplier 234, whereby it possible to shorten the cooling time of
the gas supplier 234.
[0164] (i) In the step d, by maintaining the temperature state of
the heater 248e set to a predetermined temperature in the step b,
it is possible to keep a state where the heated first gas may be
stably supplied under the same conditions. As a result, for
example, when continuous processing is performed on the wafer 200,
it is possible to quickly and stably supply the heated first gas
under the same conditions as needed.
[0165] (j) In the step b, the heated first gas supplied into the
buffer space 233 is supplied to the wafer 200 via the buffer space
233. In the step d, the unheated third gas supplied into the buffer
space 233 is exhausted via the exhaust pipe 263 installed at the
gas supplier 234 without being supplied to the wafer 200. As a
result, in the step d, it is possible to avoid the wafer 200 from
being cooled, while the buffer space 233 (the gas supplier 234) is
being cooled.
[0166] (k) Between the step a and the step b, in a state where the
wafer 200 is accommodated in the transfer space 203, by performing
the step g of heating the wafer 200 by supplying the heated fourth
gas to the wafer 200, a timing of starting pre-heating of the wafer
200 may be made faster, whereby it possible to shorten the heating
time of the wafer 200.
[0167] (l) After the step c, by performing the step h of cooling
the wafer 200 by supplying the third gas to the wafer 200, it is
possible to cool the wafer 200 in the process container 202 after
the film-forming process. As a result, the time taken for the
temperature of the processed wafer 200 to reach a temperature at
which the processed wafer 200 may be transferred may be shortened,
whereby it possible to unload the processed wafer 200 quickly from
the inside of the process container 202 (the transfer space 203)
after the film-forming process. Further, in the step h, the
processed wafer 200 may be cooled in a state where the substrate
mounting stand 212 is lowered to mount the processed wafer 200 on
the lift pins 207 such that the processed wafer 200 and the
substrate mounting stand 212 are separated from each other. This
makes it possible to further improve the cooling efficiency of the
wafer 200.
[0168] (m) By using the inert gas as the first gas and the third
gas and using the processing gas (reactive gas) as the second gas,
it is possible to prevent the occurrence of unexpected
decomposition and the like due to the processing gas heated by the
gas supplier 234 in the step c, whereby it possible to improve the
film thickness uniformity for each wafer.
(4) MODIFICATIONS
[0169] The configuration of the substrate processing apparatus 100
in the embodiments may be changed as in the following modifications
described below.
First Modification
[0170] FIG. 3 is a schematic configuration view of a main part of
the substrate processing apparatus 100 in a first modification.
Unless otherwise stated, a configuration of the substrate
processing apparatus 100 in the first modification is the same as
the configuration of the substrate processing apparatus 100 in the
aforementioned embodiments. Constituent elements having the same
function and configuration are denoted by the same reference
numerals, and explanation thereof will not be repeated.
[0171] The substrate processing apparatus in the first modification
shown in FIG. 3 is different from the substrate processing
apparatus 100 in the aforementioned embodiments mainly in the
following three points. The gas supply pipe 241 in the
aforementioned embodiments is configured such that the leading end
241a is disposed while being exposed to the inside of the shower
head buffer chamber 232, whereas a gas guide 237 is connected to a
downstream end of a gas supply pipe 240 in the first modification.
Further, the plurality of through-holes 234a in the aforementioned
embodiments are provided to be adjacent to the through-holes 234b,
whereas a plurality of through-holes 234h in the first modification
are circumferentially formed at a structure 235 circumferentially
placed at a lower wall 234i of the gas supplier 234. Further, the
gas supply pipe 236 in the aforementioned embodiments is configured
so that the downstream end of the gas supply pipe 236 is connected
to the gas introduction hole formed at the upper wall 234e of the
gas supplier 234, whereas a gas supply pipe 238 in the first
modification is configured such that a downstream end of the gas
supply pipe 238 is connected to the structure 235.
[0172] Specifically, as shown in FIG. 3, the gas guide 237
configured to guide the second gas supplied from the gas supply
pipe 240 into the through-holes 234b is connected to the downstream
end of the gas supply pipe 240 in the first modification. In this
way, the gas supply pipe 240 is in fluid communication with the
through-holes 234b via the gas guide 237. The second gas supplied
from the gas supply pipe 240 is supplied into the through-holes
234b via the gas guide 237 and is supplied to the wafer 200 via the
through-holes 234b.
[0173] Further, as shown in FIG. 3, the structure 235 configured to
supply the first gas (heating gas), which is supplied from the gas
supply pipe 238, into the through-holes 234h without being
discharged into the buffer space 233 is connected to the downstream
end of the gas supply pipe 238. In this way, the gas supply pipe
238 is in fluid communication with the through-holes 234h via the
structure 235. The first gas (heating gas) supplied from the gas
supply pipe 238 is supplied into the through-holes 234h via the
structure 235 and is supplied to the wafer 200 via the inside of
the through-holes 234h.
[0174] In this way, by separating a supply route of the second gas
and a supply route of the heated first gas without sharing them, it
is possible to prevent the supply route of the second gas from
being heated by the heated first gas. This makes it possible to
shorten the processing time of the step d.
[0175] Further, the plurality of through-holes 234h are only formed
circumferentially at the structure 235 circumferentially placed at
the lower wall 234i of the gas supplier 234, and the number of
through-holes 234h formed near a central side of the wafer 200
differs from the number of through-holes 234h formed near an outer
peripheral side of the wafer 200. Specifically, the number of
through-holes 234h formed near the outer peripheral side of the
wafer 200 is larger than the number of through-holes 234h formed
near the central side of the wafer 200. With such a configuration,
the heated first gas is supplied more toward the outer peripheral
side of the wafer 200 than toward the central side of the wafer
200. Further, the first gas (heating gas) supplied to the outer
peripheral side of the wafer 200 may diffuse and then reach the
central side of the wafer 200, such that the temperature of the
first gas supplied to the outer peripheral side of the wafer 200 is
likely to be higher than the temperature of the first gas supplied
to the central side of the wafer 200. In general, in the substrate
mounting stand 212, because heat is conducted from the outer
peripheral side of the substrate mounting stand 212 toward the wall
of the process container 202, the temperature on the outer
peripheral side of the substrate mounting stand 212 tends to be
lower than the temperature on the central side of the substrate
mounting stand 212. When the wafer 200 is heated in this state, a
temperature difference may occur between the central side and the
outer peripheral side of the wafer 200, which may cause a warp in
the wafer 200. However, since the temperature of the first gas
supplied to the outer peripheral side of the wafer 200 is higher
than the temperature of the first gas supplied to the central side
of the wafer 200, a wafer in-plane temperature may be made uniform,
whereby it possible to prevent the wafer 200 from warping. Further,
the through-holes 234h may be formed near the central side of the
wafer 200. The aforementioned effects may be obtained by making the
number of through-holes 234h near the outer peripheral side of the
wafer 200 larger than the number of through-holes 234h near the
central side of the wafer 200. Further, the aforementioned effects
may be obtained when sizes of the through-holes 234h near the outer
peripheral side of the wafer 200 are made larger than sizes of the
through-holes 234h near the central side of the wafer 200.
[0176] Further, in the modification, the same effects as those of
the aforementioned embodiments may be obtained.
Other Embodiments of the Present Disclosure
[0177] The embodiments of the present disclosure have been
described above in detail. However, the present disclosure is not
limited to the aforementioned embodiments, but may be variously
modified without departing from the gist of the present
disclosure.
[0178] The examples in which the third gas supply system 258 and
the first gas supply system 248 are completely independent from
each other and the third gas is supplied to the gas supplier 234
without going through the first gas supply system 248 have been
described in the aforementioned embodiments. However, the present
disclosure is not limited thereto. For example, as shown in FIG. 4,
the third gas supply system 260 may be connected to the gas supply
pipe 236 (the first gas supply system 248), such that the third gas
may be supplied from the third gas supply system 260 to the gas
supplier 234 via the first gas supply line. Even in such a case, at
least some of the effects described in the aforementioned
embodiments can be obtained.
[0179] In the aforementioned embodiments, various processes have
been described without specifically limiting the gas types of the
first gas and the third gas. For example, the same gas, that is,
the same type of gas, may be used as the first gas and the third
gas. That is, gases having the same molecular structure may be used
as the first gas and the third gas. For example, when an inert gas
is used as the first gas and the third gas, the same inert gas,
that is, the inert gas having the same molecular structure may be
used. As a result, gas substitution in the process container 202
may be easily performed, thereby improving a throughput. Further,
different gases, that is, different types of gases, may be used as
the first gas and the third gas. That is, gases having different
molecular structures may be used as the first gas and the third
gas. For example, when an inert gas is used as the first gas and
the third gas, different inert gases, that is, inert gases having
different molecular structures, may be used. As a result, an
appropriate gas may be selected as the first gas and the third gas
according to a goal, thereby increasing a degree of freedom of
processing in each step.
[0180] The cases where, for example, an inert gas is used as the
first gas have been described in the aforementioned embodiments. In
those cases, it has also been described that, for example, the rare
gases such as the N.sub.2 gas, the Ar gas, the He gas, the Ne gas,
and the Xe gas may be used as the inert gas. It has also been
described that the H.sub.2 gas may be used as the first gas.
[0181] Among those gases, at least one selected from the group of
the N.sub.2 gas, the H.sub.2 gas, and the He gas as the first gas
may be used in some embodiments. These gases have relatively high
thermal conductivities, and by using such gases having the high
thermal conductivities as the first gas, it is possible to shorten
the heating time, that is, the temperature rise time, of the wafer
200 in the step g, the step b, and the step e and further make the
in-plane temperature distribution of the wafer 200 more uniform in
a shorter time. Further, the thermal conductivities of these gases
is higher in the order of H.sub.2 gas, He gas, and N.sub.2 gas (the
thermal conductivity of H.sub.2 gas is the highest), and among
these gases, the thermal conductivities of H.sub.2 gas and He gas
are much higher than the thermal conductivity of N.sub.2 gas. From
these facts, when considering the thermal conductivity, at least
one selected from the group of H.sub.2 gas and He gas may be used
as the first gas in some embodiments. When at least one selected
from the group of H.sub.2 gas and He gas is used as the first gas,
the temperature rise time of the wafer 200 in the step g, the step
b, and the step e can be further shortened as compared with when
the N.sub.2 gas is used as the first gas, whereby it possible to
make the in-plane temperature distribution of the wafer 200 more
uniform in a shorter time.
[0182] Further, by using a reducing gas such as a H.sub.2 gas as
the first gas, it is possible not only to shorten the temperature
rise time of the wafer 200 in the step g, the step b, and the step
e but also to effectively remove impurities such as natural oxide
films formed on the surface of the wafer 200 and organic substances
existing on the surface of the wafer 200. That is, by using the
reducing gas such as the H.sub.2 gas as the first gas, it is
possible to perform pre-treatment, specifically pre-cleaning, on
the wafer 200 before the film-forming process. Thus, it possible to
improve the interface characteristics at the interface between the
wafer 200 and the film formed on the wafer 200, which can result in
improvement of electrical characteristics. Further, in the step f,
by supplying the reducing gas such as the H.sub.2 gas as the first
gas into the process chamber 201 via the buffer space 233, it is
also possible to remove contaminants such as organic substances
adhering to the inside of the buffer space 233 and the inside of
the process chamber 201 to clean the interior of the buffer space
233 and the interior of the process chamber 201. When performing
such processes, the reducing gas such as the H.sub.2 gas may be
activated, for example, excited into a plasma state to be supplied,
and in this case, it is possible to enhance the effects by each of
the aforementioned processes.
[0183] Further, the cases where, for example, an inert gas is used
as the third gas have been described in the aforementioned
embodiments. In those cases, it has also been described that, for
example, the rare gases such as the N.sub.2 gas, the Ar gas, the He
gas, the Ne gas, and the Xe gas may be used as the inert gas. It
has also been described that the H.sub.2 gas may be used as the
third gas.
[0184] Among these gases, at least one selected from the group of
the N.sub.2 gas, the H.sub.2 gas, and the He gas as the third gas
in some embodiments. These gases have relatively high thermal
conductivities, and by using such gases having the high thermal
conductivities as the third gas, it is possible to shorten the
cooling time of the gas supplier 234 in the step d. Further, it is
possible to shorten the cooling time of the wafer 200 in the step
h. When considering the thermal conductivity, at least one selected
from the group of H.sub.2 gas and He gas as the third gas in some
embodiments. When at least one selected from the group of H.sub.2
gas and He gas is used as the third gas, the cooling time of the
gas supplier 234 in the step d may be further shortened as compared
with when the N.sub.2 gas is used as the third gas. Further, when
at least one selected from the group of H.sub.2 gas and He gas is
used as the third gas, the cooling time of the wafer 200 in the
step h may be further shortened as compared with when the N.sub.2
gas is used as the third gas.
[0185] Further, by using a reducing gas such as the H.sub.2 gas as
the third gas, it is possible not only to shorten the cooling time
of the wafer 200 in the step h but also to effectively remove
impurities remaining on the surface and the like of a film formed
on the wafer 200. That is, by using the reducing gas such as the
H.sub.2 gas as the third gas, it is also possible to perform
post-treatment on the wafer 200 after the film-forming process.
Thus, it possible to improve the film characteristics of the film
formed on the wafer 200, which can result in improvement of the
electrical characteristics. Further, in this case, the reducing gas
such as the H.sub.2 gas may be activated, for example, excited into
a plasma state to be supplied, and in this case, it is possible to
enhance the effects by the aforementioned processes.
[0186] The cases where, for example, the inert gas is used as the
fourth gas have been described in the aforementioned embodiments.
In those cases, it has also been described that, for example, the
rare gases such as the N.sub.2 gas, the Ar gas, the He gas, the Ne
gas, and the Xe gas may be used as the inert gas. It has also been
described that the H.sub.2 gas may be used as the fourth gas.
[0187] Among these gases, at least one selected from the group of
the N.sub.2 gas, the H.sub.2 gas, and the He gas may be used as the
fourth gas. These gases have relatively high thermal
conductivities, and by using such gases having the high thermal
conductivities as the fourth gas, it is possible to shorten the
heating time, that is, the temperature rise time, of the wafer 200
in the step g, the step b, and the step e and further make the
in-plane temperature distribution of the wafer 200 more uniform in
a shorter time. When considering the thermal conductivity, at least
one selected from the group of H.sub.2 gas and He gas may be used
as the fourth gas in some embodiments. When at least one selected
from the group of H.sub.2 gas and He gas is used as the fourth gas,
the temperature rise time of the wafer 200 in the step g, the step
b, and the step e may be further shortened as compared with when
the N.sub.2 gas is used as the fourth gas, whereby it possible to
make the in-plane temperature distribution of the wafer 200 more
uniform in a shorter time.
[0188] Further, by using the reducing gas such as the H.sub.2 gas
as the fourth gas, it is possible not only to shorten the
temperature rise time of the wafer 200 in the step g, the step b,
and the step e but also to effectively remove impurities such as
natural oxide films formed on the surface of the wafer 200 and
organic substances existing on the surface of the wafer 200. That
is, by using the reducing gas such as the H.sub.2 gas as the fourth
gas, it is possible to perform pre-treatment, specifically
pre-cleaning, on the wafer 200 before the film-forming process.
This makes it possible to improve the interface characteristics at
the interface between the wafer 200 and the film formed on the
wafer 200, which can result in improvement of the electrical
characteristics. Further, in the step f, by supplying the reducing
gas such as the H.sub.2 gas as the fourth gas into the process
chamber 201 via the buffer space 233, it is also possible to remove
contaminants such as organic substances adhering to the inside of
the buffer space 233 and the inside of the process chamber 201 to
clean the interior of the buffer space 233 and the interior of the
process chamber 201. When performing such processes, the reducing
gas such as the H.sub.2 gas may be activated, for example, excited
into a plasma state, to be supplied, and in this case, it is
possible to enhance the effects by each of the aforementioned
processes.
[0189] The examples in which the plurality of through-holes 234a
and 234b are formed have been described in the aforementioned
embodiments. However, the present disclosure is not limited
thereto. For example, only one through-hole 234a and only one
through-hole 234b may be formed. Even in such a case, at least some
of the effects described in the aforementioned embodiments may be
obtained.
[0190] Further, the examples in which the silane-based gas is
mainly used as the precursor gas have been described in the
aforementioned embodiments. However, the present disclosure is not
limited thereto. For example, by using a precursor gas containing a
metal element such as aluminum (Al), titanium (Ti), hafnium (Hf),
zirconium (Zr), tantalum (Ta), molybdenum (Mo), and tungsten (W), a
film containing a metal element, such as an aluminum nitride film
(AlN film), a titanium nitride film (TiN film), a hafnium nitride
film (HfN film), a zirconium nitride film (ZrN film), a tantalum
nitride film (TaN film), a molybdenum nitride film (MoN film), a
tungsten nitride film (WN film), an aluminum oxide film (AlO film),
a titanium oxide film (TiO film), a hafnium oxide film (HfO film),
a zirconium oxide film (ZrO film), a tantalum oxide film (TaO
film), a molybdenum oxide film (MoO film), a tungsten oxide film
(WO film), a titanium oxynitride film (TiON film), a titanium
aluminum carbonitride film (TiAlCN film), a titanium aluminum
carbide film (TiAlC film), or a titanium carbonitride film (TiCN
film), may be formed on a substrate according to the aforementioned
film-forming sequence. Even in such a case, at least some of the
effects described in the aforementioned embodiments may be
obtained.
[0191] Further, the examples in which the silicon nitride film is
formed by using the nitriding gas as the reaction gas have been
described in the aforementioned embodiments. However, the present
disclosure is not limited thereto. For example, by using an
O-containing gas such as an O.sub.2 gas or a C-containing gas such
as a propylene (C.sub.3H.sub.6) gas as the reaction gas, a film
containing Si, such as a silicon oxide film (SiO film), a silicon
carbide film (SiC film), or a silicon oxycarbide film (SiOC film),
may be formed on the substrate according to the aforementioned
film-forming sequence. Even in such a case, at least some of the
effects described in the aforementioned embodiments may be
obtained.
[0192] The examples in which the temperature of the gas supplier
234 is regulated according to the processing conditions including
the supply flow rate, the supply time, and the temperature of the
gas set in advance without measuring the temperature of the gas
supplier 234 have been described in the aforementioned embodiments.
However, the present disclosure is not limited thereto. For
example, as shown in FIG. 1, a thermocouple 290 may be buried in
the gas supplier 234 such that the temperature of the gas supplier
234 may be measured by a temperature measuring part 291 connected
to the thermocouple 290. With this configuration, the temperature
of the gas supplier 234 may be measured, and each part may be
feedback-controlled based on the measured temperature data. Such
feedback control makes it possible to precisely control the
temperature of the gas supplier 234. Further, such a control makes
it possible to suppress a temperature regulation time from being
prolonged due to occurrence of an overshoot in the temperature of
the gas supplier 234, and the like.
[0193] The configuration in which one or more selected from the
group of the heated inert gas, the reducing gas, and the gas having
the high thermal conductivity may be supplied into the buffer space
233 has been described in the aforementioned embodiments. However,
the present disclosure is not limited to this configuration. For
example, as shown in FIG. 5, the gas supply pipe 236 may be
connected to the common gas supply pipe 242. With such a
configuration, at least some of the effects described in the
aforementioned embodiments can be obtained. In addition, the
structure of the substrate processing apparatus may be simplified,
which makes it possible to facilitate maintenance and reduce
apparatus costs.
[0194] The cases in which the film-forming process is performed
have been described in the aforementioned embodiments. However, the
present disclosure is not limited thereto. For example, a part of
the aforementioned embodiments may be applied to a case of cleaning
the interior of the process container 202. When cleaning, without
loading a product wafer 200 into the process container 202, for
example, the step g, the step b, and the step d may be performed
before the cleaning process, and the step h may be performed after
the cleaning process. In the cleaning process, a F-containing gas
such as a fluorine (F.sub.2) gas may be supplied as a cleaning gas
from the gas supply pipe 245a. Even in this case, at least some of
the effects described in the aforementioned embodiments may be
obtained. By the step d performed before the cleaning process, it
is possible to prevent corrosion and cleaning damage of the gas
supplier 234. Further, by the step h performed after the cleaning
process, it is possible to remove the residual fluorine in the
process container 202.
Aspects of the Present Disclosure
[0195] Hereinafter, some aspects of the present disclosure will be
additionally described as supplementary notes.
Supplementary Note 1
[0196] According to some embodiments of the present disclosure,
there is provided a method of manufacturing a semiconductor device,
including:
[0197] (a) loading a substrate into a process container;
[0198] (b) heating the substrate by supplying a first gas, which is
heated when passing through a first heater installed at a first gas
supply line, to the substrate via a gas supplier;
[0199] (c) supplying a second gas, which flows through a second gas
supply line different from the first gas supply line, to the
substrate mounted on a substrate mounting table in the process
container, via the gas supplier; and
[0200] (d) lowering a temperature of the gas supplier by supplying
a third gas, which has a temperature lower than that of the first
gas, to the gas supplier between (b) and (c).
Supplementary Note 2
[0201] In the method of Supplementary Note 1, in (b), the substrate
is held in a floating state without being mounted on the substrate
mounting table, and the substrate is heated from a rear surface of
the substrate by a second heater installed at the substrate
mounting table.
Supplementary Note 3
[0202] In the method of Supplementary Note 1 or 2, the method
further includes:
[0203] (e) holding the substrate in a state of being mounted on the
substrate mounting table, and heating the substrate from a rear
surface by heat conduction from the substrate mounting table heated
by a second heater before (c).
Supplementary Note 4
[0204] In the method of any one of Supplementary Notes 1 to 3, in
(b), the gas supplier is heated by a second heater installed at the
substrate mounting table.
Supplementary Note 5
[0205] In the method of any one of Supplementary Notes 1 to 4, the
method further includes: (f) heating the gas supplier by a second
heater installed at the substrate mounting table before (a).
Supplementary Note 6
[0206] In the method of Supplementary Note 5, a distance between
the gas supplier and the substrate mounting table in (f) is made
shorter than a distance between the gas supplier and the substrate
mounting table in (c).
Supplementary Note 7
[0207] In the method of any one of Supplementary Notes 1 to 6, in
(d), the third gas is supplied from a third gas supply line
different from the first gas supply line to the gas supplier.
Supplementary Note 8
[0208] In the method of any one of Supplementary Notes 1 to 7, in
(d), the third gas is supplied from a third gas supply line
different from the first gas supply line to the gas supplier via
the first gas supply line.
Supplementary Note 9
[0209] In the method of any one of Supplementary Notes 1 to 8, in
(d), the third gas is supplied from a third gas supply line
different from the first gas supply line to the gas supplier
without flowing through the first gas supply line.
Supplementary Note 10
[0210] In the method of any one of Supplementary Notes 1 to 9, in
(d), a temperature state of the first heater set to a predetermined
temperature in (b) is maintained.
Supplementary Note 11
[0211] In the method of any one of Supplementary Notes 1 to 10, in
(b), the first gas supplied into a buffer space installed at the
gas supplier is supplied to the substrate via the buffer space, and
in (d), the third gas supplied into the buffer space is exhausted
via an exhauster installed at the gas supplier without being
supplied to the substrate.
Supplementary Note 12
[0212] In the method of any one of Supplementary Notes 1 to 11, in
(b), the first gas is supplied to the substrate via a first gas
supply port installed at the gas supplier and being in fluid
communication with the first gas supply line, and in (c), the
second gas is supplied to the substrate via a second gas supply
port installed at the gas supplier and being in fluid communication
with the second gas supply line.
Supplementary Note 13
[0213] In the method of any one of Supplementary Notes 1 to 12, the
method further includes: (g) heating the substrate by supplying a
fourth gas, which is heated when passing through a fourth heater
installed at a fourth gas supply line, to the substrate in a state
where the substrate is accommodated in a transfer chamber installed
in the process container between (a) and (b).
Supplementary Note 14
[0214] In the method of any one of Supplementary Notes 1 to 13, the
method further includes: (h) cooling the substrate by supplying the
third gas to the substrate after (c).
Supplementary Note 15
[0215] In the method of any one of Supplementary Notes 1 to 14, the
gas supplier is configured to face an upper surface of the
substrate, and in (b), a temperature of the first gas supplied to
an outer peripheral side of the substrate is made higher than a
temperature of the first gas supplied to a central side of the
substrate.
Supplementary Note 16
[0216] In the method of any one of Supplementary Notes 1 to 15,
supply ports configured such that the first gas passes through the
supply ports and is supplied to the substrate are installed at the
gas supplier, and in (b), the first gas is supplied to the
substrate via the gas supplier configured such that at least one
selected from the group of the number of the supply ports and sizes
of the supply ports near a central side of the substrate is
different from that near an outer peripheral side of the
substrate.
Supplementary Note 17
[0217] In the method of any one of Supplementary Notes 1 to 16, in
(b), at least one selected from the group of a N.sub.2 gas, a
H.sub.2 gas, and a He gas is used as the first gas.
Supplementary Note 18
[0218] In the method of any one of Supplementary Notes 14 to 17, in
(h), at least one selected from the group of a N.sub.2 gas, a
H.sub.2 gas, a He gas, a diluted H.sub.2 gas, and an activated
H.sub.2 gas is used as the third gas.
Supplementary Note 19
[0219] In the method of any one of Supplementary Notes 1 to 18, an
inert gas is used as the first gas and the third gas, and a
processing gas (a reactive gas) is used as the second gas.
Supplementary Note 20
[0220] In the method of any one of Supplementary Notes 1 to 19, the
first gas and the third gas are the same gas (the gas having the
same type and the same molecular structure).
Supplementary Note 21
[0221] According to other embodiments of the present disclosure,
there is provided a substrate processing apparatus including:
[0222] a process container in which a substrate is
accommodated;
[0223] a transfer mechanism configured to transfer the substrate
into the process container;
[0224] a substrate mounting table configured to mount the substrate
in the process container;
[0225] a gas supplier configured to supply a gas to the substrate
in the process container;
[0226] a first gas supply line including a first heater and being
configured to supply a first gas via the gas supplier;
[0227] a second gas supply line configured to supply a second gas
via the gas supplier;
[0228] a third gas supply line configured to supply a third gas to
the gas supplier; and
[0229] a controller configured to be capable of controlling the
transfer mechanism, the first gas supply line, the second gas
supply line, and the third gas supply line to perform each process
(each step) of Supplementary Note 1 in the process container.
Supplementary Note 22
[0230] According to other embodiments of the present disclosure,
there is provided a program that causes, by a computer, a substrate
processing apparatus to perform each process (each step) of
Supplementary Note 1 or a computer-readable storage medium storing
the program.
[0231] According to the present disclosure in some embodiments, it
is possible to improve a processing uniformity and a throughput for
each substrate.
[0232] While certain embodiments have been described, these
embodiments have been presented by way of example only, and are not
intended to limit the scope of the disclosures. Indeed, the
embodiments described herein may be embodied in a variety of other
forms. Furthermore, various omissions, substitutions and changes in
the form of the embodiments described herein may be made without
departing from the spirit of the disclosures. The accompanying
claims and their equivalents are intended to cover such forms or
modifications as would fall within the scope and spirit of the
disclosures.
* * * * *