U.S. patent application number 16/715456 was filed with the patent office on 2020-04-16 for integrated substrate temperature measurement on high temperature ceramic heater.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Rupankar CHOUDHURY, Hanish Kumar PANAVALAPPIL KUMARANKUTTY, Jay D. PINSON, II, Jason M. SCHALLER, Yizhen ZHANG.
Application Number | 20200118850 16/715456 |
Document ID | / |
Family ID | 64014870 |
Filed Date | 2020-04-16 |
![](/patent/app/20200118850/US20200118850A1-20200416-D00000.png)
![](/patent/app/20200118850/US20200118850A1-20200416-D00001.png)
![](/patent/app/20200118850/US20200118850A1-20200416-D00002.png)
![](/patent/app/20200118850/US20200118850A1-20200416-D00003.png)
United States Patent
Application |
20200118850 |
Kind Code |
A1 |
ZHANG; Yizhen ; et
al. |
April 16, 2020 |
INTEGRATED SUBSTRATE TEMPERATURE MEASUREMENT ON HIGH TEMPERATURE
CERAMIC HEATER
Abstract
Embodiments described herein include integrated systems used to
directly monitor a substrate temperature during a plasma enhanced
deposition process and methods related thereto. In one embodiment,
a substrate support assembly includes a support shaft, a substrate
support disposed on the support shaft, and a substrate temperature
monitoring system for measuring a temperature of a substrate to be
disposed on the substrate support. The substrate temperature
monitoring system includes a optical fiber tube, a light guide
coupled to the optical fiber tube, and a cooling assembly disposed
about a junction of the optical fiber tube and the light guide.
Herein, at least a portion of the light guide is disposed in an
opening extending through the support shaft and into the substrate
support and the cooling assembly maintains the optical fiber tube
at a temperature of less than about 100.degree. C. during substrate
processing.
Inventors: |
ZHANG; Yizhen; (San Jose,
CA) ; CHOUDHURY; Rupankar; (BANGALORE, IN) ;
PINSON, II; Jay D.; (San Jose, CA) ; SCHALLER; Jason
M.; (Austin, TX) ; PANAVALAPPIL KUMARANKUTTY; Hanish
Kumar; (Bangalore, IN) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
64014870 |
Appl. No.: |
16/715456 |
Filed: |
December 16, 2019 |
Related U.S. Patent Documents
|
|
|
|
|
|
Application
Number |
Filing Date |
Patent Number |
|
|
15970496 |
May 3, 2018 |
10510567 |
|
|
16715456 |
|
|
|
|
62500682 |
May 3, 2017 |
|
|
|
Current U.S.
Class: |
1/1 |
Current CPC
Class: |
G01J 5/0818 20130101;
G01J 5/042 20130101; G01J 5/046 20130101; H01J 37/32724 20130101;
G01J 5/061 20130101; G02B 6/4268 20130101; G01J 5/0255 20130101;
G01J 5/048 20130101; H01L 21/67109 20130101; C23C 16/4586 20130101;
H01L 21/67248 20130101; H01L 21/68792 20130101; C23C 16/463
20130101; G01J 5/0007 20130101; G01J 5/0821 20130101; C23C 16/4581
20130101; C23C 16/52 20130101 |
International
Class: |
H01L 21/67 20060101
H01L021/67; C23C 16/46 20060101 C23C016/46; C23C 16/458 20060101
C23C016/458; G02B 6/42 20060101 G02B006/42; G01J 5/08 20060101
G01J005/08; G01J 5/04 20060101 G01J005/04; H01L 21/687 20060101
H01L021/687; G01J 5/06 20060101 G01J005/06; H01J 37/32 20060101
H01J037/32; G01J 5/00 20060101 G01J005/00; C23C 16/52 20060101
C23C016/52; G01J 5/02 20060101 G01J005/02 |
Claims
1. A method of processing a substrate, comprising: positioning a
substrate on a substrate receiving surface of a substrate support
assembly disposed in a processing volume of a processing chamber;
measuring a temperature of the substrate using an optical fiber
tube, wherein the temperature of the substrate exceeds about
110.degree. C.; maintaining the optical fiber tube at a temperature
of temperature less than about 100.degree. C.; and depositing a
material layer on the substrate.
2. The method of claim 1, wherein the temperature of the substrate
exceeds about 250.degree. C.
3. The method of claim 1, further comprising: flowing one or more
processing gases into the processing volume; and forming a plasma
of the one or more processing gases.
4. The method of claim 3, further comprising monitoring the
measured substrate temperature and changing one or more processing
conditions responsive to determining that the substrate temperature
exceeds a threshold value.
5. The method of claim 1, wherein the substrate support assembly
comprises: a support shaft; a substrate support disposed on the
support shaft; and a substrate temperature monitoring system for
measuring a temperature of a substrate to be disposed on the
substrate support, comprising: the optical fiber tube; a light
guide coupled to the optical fiber tube, wherein at least a portion
of the light guide is disposed in an opening extending through the
support shaft and into the substrate support; and a cooling
assembly disposed about a junction of the optical fiber tube and
the light guide.
6. The method of claim 5, wherein the light guide comprises a tube
having a length of at least about 400 mm and an inner diameter of
at least 40 mm.
7. The method of claim 5, wherein the light guide comprises a
sapphire tube having an inner diameter of at least 40 mm.
8. The method of claim 1, wherein measuring the temperature of the
substrate comprises measuring IR radiation emitted by and/or
reflected from a non-active surface of the substrate.
9. The method of claim 8, wherein the IR radiation is directed from
the non-active surface of the substrate to the optical fiber tube
using a light guide coupled to the optical fiber tube.
10. The method of claim 9, wherein maintaining the optical fiber
tube at a temperature of less than about 100.degree. C. comprises
maintaining a junction of the optical fiber tube and the light
guide at a temperature of less than about 100.degree. C.
11. A method of processing a substrate, comprising: positioning a
substrate on a substrate receiving surface of a substrate support
assembly disposed in a processing volume of a processing chamber;
flowing one or more processing gases into the processing volume;
forming a plasma of the one or more processing gases; measuring a
temperature of the substrate using an optical fiber tube, wherein
the temperature of the substrate exceeds about 110.degree. C.,
maintaining the optical fiber tube at a temperature of less than
about 100.degree. C.; and depositing a material layer on the
substrate.
12. The method of claim 11, wherein the optical fiber tube is
coupled to a light guide, and wherein maintaining the optical fiber
tube at a temperature of less than about 100.degree. C. comprises
maintaining a junction of the optical fiber tube and the light
guide at a temperature of less than about 100.degree. C.
13. The method of claim 12, wherein the light guide comprises a
tube having an inner diameter of at least about 40 mm.
14. The method of claim 13, wherein measuring the temperature of
the substrate includes measuring IR radiation emitted by and/or
reflected from a non-active surface of the substrate.
15. The method of claim 14, wherein the IR radiation is directed
from the non-active surface of the substrate to the optical fiber
tube using the light guide.
16. A non-transitory computer readable medium having instructions
stored thereon for performing a method of processing a substrate
when executed by a processor, the method comprising: positioning a
substrate on a substrate receiving surface of a substrate support
assembly disposed in a processing volume of a processing chamber;
flowing one or more processing gases into the processing volume;
forming a plasma of the one or more processing gases; measuring a
temperature of the substrate using an optical fiber tube, wherein
the temperature of the substrate exceeds about 110.degree. C.,
maintaining the optical fiber tube at a temperature of less than
about 100.degree. C.; and depositing a material layer on the
substrate.
17. The method of claim 16, further comprising monitoring the
measured substrate temperature and changing one or more processing
conditions responsive to determining that the substrate temperature
exceeds a threshold value.
18. The method of claim 16, wherein measuring the temperature of
the substrate comprises measuring IR radiation emitted by and/or
reflected from a non-active surface of the substrate.
19. The method of claim 16, wherein the optical fiber tube is
coupled to a light guide, and wherein maintaining the optical fiber
tube at a temperature of less than about 100.degree. C. comprises
maintaining a junction of the optical fiber tube and the light
guide at a temperature of less than about 100.degree. C.
20. The method of claim 19, wherein the light guide comprises a
tube having an inner diameter of at least about 40 mm.
Description
CROSS-REFERENCE TO RELATED APPLICATIONS
[0001] This application is a divisional of U.S. patent application
Ser. No. 15/970,496, filed May 3, 2018, issuing as U.S. Pat. No.
10,510,567 on Dec. 17, 2019, which claims priority to U.S.
Provisional Application Ser. No. 62/500,682, filed May 3, 2017.
Each of the aforementioned related patent applications is herein
incorporated by reference in its entirety.
BACKGROUND
Field
[0002] Embodiments described herein generally relate to plasma
enhanced semiconductor device manufacturing processes, and more
specifically to a substrate temperature monitoring system used in a
plasma enhanced chemical vapor deposition chamber (PECVD) and
methods related thereto.
Description of the Related Art
[0003] Semiconductor device manufacturing involves a number of
different chemical and physical processes enabling minute
integrated circuits to be created on a substrate. Layers of
materials, which make up the integrated circuit, are created by
chemical vapor deposition, physical vapor deposition, epitaxial
growth, and the like.
[0004] In the manufacture of integrated circuits, plasma enhanced
processes are often used for deposition or etching of various
material layers. Plasma enhanced processing offers many advantages
over thermal processing. For example, plasma enhanced chemical
vapor deposition (PECVD) allows deposition processes to be
performed at lower temperatures and at higher deposition rates than
achievable in analogous thermal processes. Thus, PECVD is
advantageous for semiconductor device manufacturing processes with
stringent thermal budgets, such as for back end of the line (BEOL)
processes for very large scale or ultra-large scale integrated
circuit (VLSI or ULSI) device fabrication.
[0005] Typically, during plasma enhanced processing of a substrate
within a processing chamber, ions form the plasma will bombard the
substrate causing undesirable temporal temperature increases, e.g.,
temperature spikes, thereof. Conventional methods of monitoring
substrate temperature during substrate processing in a plasma
enhanced chamber typically rely on measuring the temperature of a
substrate support, the substrate disposed thereon, and inferring
the temperature of the substrate from the temperature of the
substrate support. Unfortunately, the low pressure atmosphere of
many plasma enhanced processes causes poor heat transfer between
the substrate and the substrate support which results in a large
temperature differential therebetween.
[0006] Accordingly, there is a need in the art for apparatus and
methods to directly monitor the temperature of a substrate during
plasma enhanced substrate processes.
SUMMARY
[0007] Embodiments described herein provide a substrate temperature
monitoring system used in a semiconductor device manufacturing
system, in particular, a temperature monitoring system for directly
monitoring the temperature of a substrate during a plasma enhanced
deposition process, such as a plasma enhanced chemical vapor
deposition (PECVD) process, and methods related thereto.
[0008] In one embodiment, a substrate support assembly includes a
support shaft, a substrate support disposed on the support shaft,
and a substrate temperature monitoring system for measuring a
temperature of a substrate to be disposed on the substrate support.
The substrate temperature monitoring system includes an optical
fiber tube, a light guide coupled to the optical fiber tube, and a
cooling assembly disposed about a junction of the optical fiber
tube and the light guide. Herein, at least a portion of the light
guide is disposed in an opening extending through the support shaft
and into the substrate support and the cooling assembly maintains
the optical fiber tube at a temperature of less than about
100.degree. C. during substrate processing.
[0009] In another embodiment, a processing chamber includes a
chamber body defining a processing volume and a substrate support
assembly disposed in the processing volume. The substrate support
assembly includes a support shaft, a substrate support disposed on
the support shaft, and a substrate temperature monitoring system
for measuring a temperature of a substrate to be disposed on the
substrate support. The substrate temperature monitoring system
includes an optical fiber tube, a light guide coupled to the
optical fiber tube, and a cooling assembly disposed about a
junction of the optical fiber tube and the light guide. Herein, at
least a portion of the light guide is disposed in an opening
extending through the support shaft and into the substrate support
and the cooling assembly maintains the optical fiber tube at a
temperature of less than about 100.degree. C. during substrate
processing.
[0010] In another embodiment, a method of processing a substrate
includes positioning a substrate on a substrate receiving surface
of a substrate support assembly disposed in a processing volume of
a processing chamber, flowing one or more processing gases into the
processing volume, forming a plasma of the one or more processing
gases, measuring a temperature of the substrate using an optical
fiber tube, wherein the temperature of the substrate exceeds about
110.degree. C., and wherein the optical fiber tube is maintained at
a temperature less than about 100.degree. C., and depositing a
material layer on the substrate.
BRIEF DESCRIPTION OF THE DRAWINGS
[0011] So that the manner in which the above recited features of
the present disclosure can be understood in detail, a more
particular description of the disclosure, briefly summarized above,
may be had by reference to embodiments, some of which are
illustrated in the appended drawings. It is to be noted, however,
that the appended drawings illustrate only typical embodiments of
this disclosure and are therefore not to be considered limiting of
its scope, for the disclosure may admit to other equally effective
embodiments.
[0012] FIG. 1 is a schematic cross sectional view of an exemplary
plasma processing chamber used to practice the methods set forth
herein, according to one embodiment.
[0013] FIG. 2A is cross sectional view of the substrate support
assembly from the plasma processing chamber of FIG. 1, according to
one embodiment.
[0014] FIG. 2B is a close up view of a portion of the substrate
support assembly shown in FIG. 2A.
[0015] FIG. 3 is a flow diagram illustrating a method of processing
a substrate, according to one embodiment.
[0016] For clarity, identical reference numerals have been used,
where applicable, to designate identical elements that are common
between figures. Additionally, elements of one embodiment may be
advantageously adapted for utilization in other embodiments
described herein.
DETAILED DESCRIPTION
[0017] Embodiments described herein provide a substrate temperature
monitoring system used in a plasma enhanced processing chamber, in
particular, a temperature monitoring system for directly monitoring
the temperature of a substrate during a plasma enhanced deposition
process, such as a plasma enhanced chemical vapor deposition
(PECVD) process, and methods related thereto.
[0018] Conventionally, during a plasma enhanced deposition
processes, such as PECVD processes, the temperature of a substrate
being processed is monitored by measuring the temperature of a
substrate support, having the substrate disposed thereon, and
inferring the temperature of the substrate therefrom.
Unfortunately, indirect measurements of the substrate temperature
are often inaccurate due to poor heat transfer between the
substrate support and the substrate or may not timely reflect
changes in the substrate temperature, such temperature spikes. This
is especially problematic in processes, such as PECVD processes,
where a low pressure atmosphere in a processing volume of the
processing chamber results poor thermal conduction between a
dielectric material of the substrate support and the substrate.
Further, conventional direct substrate temperature measuring
systems are unsuitable for the higher substrate temperatures
reached during PECVD processes, for example 550.degree. C. or more,
as the fiber optic components thereof are unable to withstand such
high temperature applications. Therefore, embodiments provided
herein allow for direct monitoring of a substrate's temperature
during plasma processing thereof at relatively high processing
temperatures, such as temperatures more than about 100.degree. C.
In particular, embodiments herein allow for direct measurements of
the temperature of a non-active surface of the substrate disposed
on the substrate support using a temperature monitoring system
disposed in and, or, extending through the substrate support
assembly.
[0019] FIG. 1 is a schematic cross sectional view of an exemplary
plasma processing chamber used to practice the methods set forth
herein, according to one embodiment. Other exemplary deposition
chambers that may be used to practice the methods describe herein
include a Producer.RTM. ETERNA CVD.RTM. system or an Ultima HDP
CVD.RTM. system, both available from Applied Materials, Inc., of
Santa Clara, Calif. as well as suitable deposition chambers from
other manufacturers.
[0020] The processing chamber 100 includes a chamber body 102 which
defines a processing volume 104, a showerhead 110 disposed in the
processing volume 104, and a substrate support assembly 120
disposed in the processing volume 104 facing the showerhead 110.
The showerhead 110, having a plurality of openings (not shown)
disposed therethrough, is used to distribute processing gases, from
the gas source 114, into the processing volume 104. Herein, the
showerhead 110 is electrically coupled to a power supply 118, such
as an RF or other ac frequency power supply, which supplies power
to ignite and maintain a plasma 112 of the processing gases through
capacitive coupling therewith. In other embodiments, the processing
chamber 100 comprises an inductive plasma generator and the plasma
is formed through inductively coupling an RF power to the
processing gas.
[0021] Herein, the substrate support assembly 120 includes a
movable support shaft 106 sealingly extending through a base wall
of the chamber body 102, such as being surrounded by bellows (not
shown) in the region below the chamber base, and a substrate
support 107 disposed on the support shaft 106 and coupled thereto.
The substrate support 107 features a first surface, herein a
substrate receiving surface 109, and a second surface 111 opposite
the first surface. In some embodiments, the substrate 101, disposed
on the substrate support 107, is maintained at a desired processing
temperature, or within a range of desired processing temperatures,
using one or both of a heater (not shown), such as a resistive
heating element, and one or more cooling channels (not shown)
disposed in the substrate support 107. Typically, the one or more
cooling channels are fluidly coupled to a coolant source (not
shown), such as a modified water source having relatively high
electrical resistance or a refrigerant source.
[0022] The processing volume 104 is fluidly coupled to a vacuum
source 126, such as to one or more dedicated vacuum pumps, which
maintains the processing volume 104 at sub-atmospheric conditions
and evacuates processing gas and other gases therefrom. Typically,
a lift pin system (not shown) facilitates transfer of a substrate
101 to and from the substrate support 107 by enabling access to the
substrate 101 by a robot handler. The substrate 101 is transferred
into and out of the processing volume 104 through an opening (not
shown) in a sidewall of the chamber body 102 which is sealed with a
door or a valve (not shown) during substrate processing.
[0023] Herein, the processing chamber 100 further includes a
controller 190 coupled thereto. The controller 190 includes a
programmable central processing unit (CPU) 192 that is operable
with a memory 194 and a mass storage device, an input control unit,
and a display unit (not shown), such as power supplies, clocks,
cache, input/output (I/O) circuits, and the liner, coupled to the
various components of the processing system to facilitate control
of the substrate processing.
[0024] To facilitate control of the processing chamber 100
described above, the CPU 192 may be one of any form of general
purpose computer processor that can be used in an industrial
setting, such as a programmable logic controller (PLC), for
controlling various chambers and sub-processors. The memory 194 is
coupled to the CPU 192 and the memory 194 is non-transitory and may
be one or more of readily available memory such as random access
memory (RAM), read only memory (ROM), floppy disk drive, hard disk,
or any other form of digital storage, local or remote. Support
circuits 196 are coupled to the CPU 192 for supporting the
processor in a conventional manner. Instructions for controlling
the operation of the processing chamber 100 are stored in the
memory 194, typically as software routine. The software routine may
also be stored and/or executed by a second CPU (not shown) that is
remotely located from the processing chamber 100 being controlled
by the CPU 192.
[0025] The memory 194 is in the form of computer-readable storage
media that contains instructions, that when executed by the CPU
192, facilitates the operation of the processing chamber 100. The
instructions in the memory 194 are in the form of a program product
such as a program that implements the method of the present
disclosure. The program code may conform to any one of a number of
different programming languages. In one example, the disclosure may
be implemented as a program product stored on a computer-readable
storage media for use with a computer system. The program(s) of the
program product define functions of the embodiments (including the
methods described herein). Illustrative computer-readable storage
media include, but are not limited to: (i) non-writable storage
media (e.g., read-only memory devices within a computer such as
CD-ROM disks readable by a CD-ROM drive, flash memory, ROM chips,
or any type of solid-state non-volatile semiconductor memory) on
which information is permanently stored; and (ii) writable storage
media (e.g., floppy disks within a diskette drive or hard-disk
drive or any type of solid-state random-access semiconductor
memory) on which alterable information is stored. Such
computer-readable storage media, when carrying computer-readable
instructions that direct the functions of the methods described
herein, are embodiments of the present disclosure.
[0026] Herein, the processing chamber 100 features a temperature
monitoring system 124 integrated with the substrate support
assembly 120, as further shown and described in FIGS. 2A-B.
[0027] FIG. 2A is a schematic cross sectional view of the substrate
support assembly 120 of the processing chamber 100 shown in FIG. 1
having a temperature monitoring system 124 integrated therewith,
according to one embodiment. FIG. 2B is a close up view of a
portion of FIG. 2A. The temperature monitoring system 124 is used
to directly measure the temperature of the substrate 101 disposed
on the substrate support 107. The temperature monitoring system 124
herein includes an optical fiber tube 212 and a light guide 214.
The optical fiber tube 212 is coupled to the light guide 214 using
one or more fasteners 230, for example a nut having both the
optical fiber tube 212 and the light guide 214 screwed thereinto at
opposite ends thereof. The light guide 214 allows for the
positioning of the optical fiber tube 212 at a location remote from
the substrate 101 and the relativity high substrate processing
temperatures associated therewith. Herein, the light guide 214
guides or directs an infrared (IR) beam emitted from the optical
fiber tube 212 up the length of the support shaft 106 towards a
non-active surface of the substrate 101 (i.e., the surface of the
substrate in contact with the substrate support 107). The IR beam
is reflected by the non-active surface of the substrate 101 and is
directed back down to the optical fiber tube 212 through the light
guide 214. In another embodiment, the optical fiber tube 212 is a
passive optical fiber tube, and the light guide 214 is used to
transmit or guide IR radiation emitted from the substrate 101 to
the passive optical fiber tube. Herein, the optical fiber tube 212
is coupled to the controller 190 which determines the temperature
of the substrate 101 based on the received IR beams emitted from or
reflected by the non-active surface of the substrate 101.
Typically, the light guide 214 is formed sapphire, such as a
sapphire tube, or any other material suitable for directing IR
light from the optical fiber tube 212 to the bottom of the
substrate 101.
[0028] A junction of the optical fiber tube 212 and light guide
214, such as the fiber optic junction 220, is disposed in a cooling
assembly 204 coupled to the support shaft 106. The cooling assembly
204 includes a temperature monitoring system adaptor, such as the
adaptor 206, for integrating the temperature monitoring system 124
with the substrate support assembly 120, and a cooling jacket 208
disposed about the adaptor 206. During substrate processing, the
cooling assembly 204 is used to maintain the temperature of the
optical fiber tube 212 at or below 110.degree. C. which prevents
damage to the optical fiber tube 212 from excessive or prolonged
exposure to thermal energy from substrate processing temperatures
up to, and in some embodiments, more than about 550.degree. C.
[0029] Herein, at least a portion of the light guide 214 is
disposed in an opening 202 which extends through the support shaft
106 and at least partially through the substrate support 107. In
some embodiments, the opening 202 extends through the substrate
support 107, for example through the substrate receiving surface
109 thereof. Typically, the opening 202 further extends through, or
extends partially through, the cooling assembly 204, so that a
continuous passage extends from the cooling assembly 204 to at
least partially through the substrate support 107, and in some
embodiments, to the substrate receiving surface 109 of the
substrate support. Herein, the opening 202 is isolated from
atmospheric conditions outside the processing volume 104 by a
vacuum seal 236, such as an 0-ring, located proximate to the fiber
optic junction 220. The fiber optic junction 220 is isolated from
the processing conditions in the processing volume 104 and the
temperatures associated therewith.
[0030] Typically, an end of the light guide 214 proximate to the
substrate 101 is positioned so that radiation, such as IR
radiation, reflected by and, or, emitted from the substrate 101 is
received into the light guide 214 and that radiation reflected by
or emitted by other surfaces, such as surfaces of the support shaft
106 and, or, the substrate support 107 is not. In some embodiments,
the light guide 214 extends from the fiber optic junction 220 to
the substrate receiving surface 109 of the substrate support 107 so
that the an end of the light guide 214 is flush with or just below
the substrate receiving surface 109. In some embodiments, the light
guide 214 extends to within about 1 mm, such as within about 0.5
mm, of the substrate receiving surface 109 so that the end of the
light guide 214 is spaced apart from a substrate positioned on the
substrate support 107 by between about 0 mm and about 1 mm, or
between about 0 mm and about 0.5 mm, or less than about 0.5 mm. In
some embodiments, the substrate support 107 further includes a
window (not shown) disposed below or flush with the substrate
receiving surface 109 and the light guide 214 extends to the window
or within 1 mm thereof, such as within 0.5 mm thereof. Typically,
the window is formed of a corrosion resistant material transparent
to IR radiation, such as sapphire, yttrium, or quartz. In some
embodiments, the window is integrally formed with substrate
receiving surface 109 of the substrate support 107. Positioning the
end of the light guide 214 within about 1 mm, such as within about
0.5 mm, from the non-active surface of a substrate 101 disposed on
the substrate support 107 desirably improves the accuracy of
substrate temperature measurement to within about 2.degree. C. for
substrate temperatures of more than about 250.degree. C.
[0031] In some embodiments, the temperature monitoring system 124
further includes a protective sheath 222 circumscribing the light
guide 214, and protecting the light guide 214 from breakage by
restricting the lateral movement thereof in the opening 202.
Typically, the sheath 222 is formed from the same or similar
material as the support shaft 106, such as alumina. In some
embodiments, the light guide 214 has a length of at least about 380
mm, for example at least about 400 mm. In some embodiments, the
light guide 214 has an inner diameter of at least about 40 mm, such
at least about 50 mm, at least about 60 mm, for example at least
about 70 mm, or at least about 80 mm.
[0032] FIG. 3 is a flow diagram illustrating a method of processing
a substrate, according to one embodiment. At activity 301, the
method 300 includes positioning the substrate on a substrate
support disposed in a processing volume of a processing chamber,
such as the processing chamber 100 described in FIG. 1 and the
substrate support described in FIGS. 1 and 2A-2B.
[0033] At activity 302, the method 300 includes flowing one or more
processing gases into the processing volume. Typically, the one or
more processing gases comprise one or more material deposition
precursor gases. The one or more material deposition precursor
gases are flowed into the processing volume concurrently,
sequentially, or a combination thereof. In some embodiments, the
one or more processing gases further comprise a diluent gas, for
example a noble gas, N.sub.2, or a combination thereof. At activity
303, the method 300 includes igniting and maintaining a plasma of
the processing gases.
[0034] At activity 304, the method 300 includes measuring a
temperature of the substrate using an optical fiber tube. Herein,
the temperature of the substrate reaches or exceeds about
110.degree. C. during substrate processing, such as more than about
150.degree. C., more than about 200.degree. C., more than about
250.degree. C., more than about 300.degree. C., more than about
350.degree. C., more than about 400.degree. C., more than about
450.degree. C., more than about 500.degree. C., for example more
than about 550.degree. C. Typically, the optical fiber tube is
maintained at a temperature of less than about 100.degree. C. to
prevent damage to thereto during the method 300.
[0035] At activity 305 the method 300 includes depositing a
material layer on the substrate. Herein, the material layer
comprises the reactive product of the one or more material
deposition precursor gases on or with the active surface of the
substrate. In some embodiments, the method 300 further includes
maintaining the processing volume at a processing pressure of less
than about 10 Torr.
[0036] In some embodiments, measuring the temperature of the
substrate includes directing IR radiation emitted by and, or,
reflected from a non-active surface of the substrate through a
light guide coupled to the optical fiber tube. In some embodiments,
maintaining the optical fiber tube at a temperature of less than
about 100.degree. C. includes maintaining a junction of the light
guide and the optical fiber tube at a temperature of less than
about 100.degree. C. In some embodiments, the method 300 further
includes emitting an IR beam from the optical fiber tube and
directing the IR beam towards the non-active surface of the
substrate through the light guide.
[0037] In some embodiments, measuring the temperature of the
substrate includes communicating optical information received by
the optical fiber tube, such as IR radiation reflected by and, or,
emitted by the substrate, to a controller coupled to the processing
chamber. In some embodiments, the method further includes
monitoring the temperature of the substrate and changing one or
more substrate processing conditions based thereon. For example, in
some embodiments, the method includes changing one or more
substrate processing conditions responsive to determining that the
temperature of the substrate exceeds a threshold value. In some
embodiments, the threshold value is a percentage increase in
temperature that is indicative of a spike, such as more than about
20% of a typical mean substrate processing temperature, such as
more than about 30% of typical mean substrate processing
temperature, or other thresholds indicative of an undesirable spike
in substrate temperature. In some embodiments, changing one or more
processing conditions includes changing one of processing gas flow
rates, a substrate processing time, processing pressure of the
processing volume, temperature of the substrate support, power
provided to the showerhead, stopping processing of the substrate,
starting a new processing sequence for the substrate, or a
combination thereof. In some embodiments, monitoring the
temperature of the substrate includes collecting substrate
temperature information that can be stored on the system controller
or a fab level software in communication therewith, for example for
statistical analysis or statistical process control (SPC) purposes.
In some embodiments, the method further includes alerting a user to
an out-of-control event, such as when a temperature of the
substrate exceeds a threshold value, using any form of alert
designed to communicate the out-of-control event to a desired user,
including visual and audio alarms.
[0038] The embodiments described herein provide for the direct
measurement and monitoring of substrate temperature in high
temperature processing environments associated with PECVD
processes, such as temperatures of 550.degree. C. or more. Direct
monitoring of substrate temperature beneficially enables improved
process control methods as well as provides data that can be used
to ensure stable and repeatable processing system performance.
[0039] While the foregoing is directed to specific embodiments,
other and further embodiments may be devised without departing from
the basic scope thereof, and the scope thereof is determined by the
claims that follow.
* * * * *