U.S. patent application number 16/109248 was filed with the patent office on 2018-12-20 for coating architecture for plasma sprayed chamber components.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Yikai Chen, Biraja P. Kanungo, Jennifer Y. Sun.
Application Number | 20180366302 16/109248 |
Document ID | / |
Family ID | 52666881 |
Filed Date | 2018-12-20 |
United States Patent
Application |
20180366302 |
Kind Code |
A1 |
Sun; Jennifer Y. ; et
al. |
December 20, 2018 |
COATING ARCHITECTURE FOR PLASMA SPRAYED CHAMBER COMPONENTS
Abstract
A method of plasma spraying an article comprises providing an
article, feeding a liquid precursor solution into a plasma spray
deposition system, and generating, with the plasma spray deposition
system, a stream directed toward the article. The stream forms a
ceramic coating on the article upon contact therewith. The ceramic
coating comprises Y.sub.2O.sub.3 and one or more of ZrO.sub.2,
Al.sub.2O.sub.3, Er.sub.2O.sub.3, Gd.sub.2O.sub.3, SiO.sub.2, or
YF.sub.3.
Inventors: |
Sun; Jennifer Y.; (Mountain
View, CA) ; Chen; Yikai; (Santa Clara, CA) ;
Kanungo; Biraja P.; (San Jose, CA) |
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Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
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|
Family ID: |
52666881 |
Appl. No.: |
16/109248 |
Filed: |
August 22, 2018 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
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15640274 |
Jun 30, 2017 |
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16109248 |
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14462057 |
Aug 18, 2014 |
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15640274 |
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61879549 |
Sep 18, 2013 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
H01J 37/32477 20130101;
Y10T 428/24967 20150115; C23C 4/134 20160101; Y10T 428/249981
20150401; C23C 4/10 20130101; H01J 37/32495 20130101; C23C 4/18
20130101; C23C 4/11 20160101 |
International
Class: |
H01J 37/32 20060101
H01J037/32; C23C 4/18 20060101 C23C004/18; C23C 4/10 20160101
C23C004/10; C23C 4/134 20160101 C23C004/134; C23C 4/11 20160101
C23C004/11 |
Claims
1. A method comprising: providing an article; feeding a liquid
precursor solution into a plasma spray deposition system; and
generating, with the plasma spray deposition system, a stream
directed toward the article, wherein the stream forms a ceramic
coating on the article upon contact therewith, and wherein the
ceramic coating comprises Y.sub.2O.sub.3 and one or more of
ZrO.sub.2, Al.sub.2O.sub.3, Er.sub.2O.sub.3, Gd.sub.2O.sub.3,
SiO.sub.2, or YF.sub.3.
2. The method of claim 1, wherein a composition of the ceramic
coating is selected from: 50-75 mol % of Y.sub.2O.sub.3, 10-30 mol
% of ZrO.sub.2, and 10-30 mol % of Al.sub.2O.sub.3; 40-100 mol % of
Y.sub.2O.sub.3, 0-60 mol % of ZrO.sub.2, and 0-10 mol % of
Al.sub.2O.sub.3; 40-60 mol % of Y.sub.2O.sub.3, 30-50 mol % of
ZrO.sub.2, and 10-20 mol % of Al.sub.2O.sub.3; 40-50 mol % of
Y.sub.2O.sub.3, 20-40 mol % of ZrO.sub.2, and 20-40 mol % of
Al.sub.2O.sub.3; 70-90 mol % of Y.sub.2O.sub.3, 0-20 mol % of
ZrO.sub.2, and 10-20 mol % of Al.sub.2O.sub.3; 60-80 mol % of
Y.sub.2O.sub.3, 0-10 mol % of ZrO.sub.2, and 20-40 mol % of
Al.sub.2O.sub.3; or 40-60 mol % of Y.sub.2O.sub.3, 0-20 mol % of
ZrO.sub.2, and 30-40 mol % of Al.sub.2O.sub.3.
3. The method of claim 1, wherein the ceramic coating comprises
ZrO.sub.2, Er.sub.2O.sub.3, Gd.sub.2O.sub.3, and SiO.sub.2.
4. The method of claim 1, wherein the ceramic coating comprises
40-45 mol % of Y.sub.2O.sub.3, 0-10 mol % of ZrO.sub.2, 35-40 mol %
of Er.sub.2O.sub.3, 5-10 mol % of Gd.sub.2O.sub.3, and 5-15 mole %
of SiO.sub.2.
5. The method of claim 1, wherein the ceramic coating comprises
YF.sub.3.
6. The method of claim 1, wherein a thickness of the ceramic
coating is from about 20 micrometers to about 500 micrometers.
7. The method of claim 1, wherein a surface roughness of the
ceramic coating is from about 100 micro-inches to about 300
micro-inches.
8. The method of claim 1, wherein a porosity of the ceramic coating
is less than about 1%.
9. The method of claim 1, wherein the article is a chamber
component selected from a group consisting of a substrate support
assembly, an electrostatic chuck, a ring, a chamber wall, a base, a
gas distribution plate, a showerhead, a liner, a liner kit, a
shield, a plasma screen, a flow equalizer, a cooling base, a
chamber viewport, a chamber lid, a nozzle, or a process kit
ring.
10. A method comprising: providing an article; feeding a liquid
precursor solution into a plasma spray deposition system; and
generating, with the plasma spray deposition system, a stream
directed toward the article, wherein the stream forms a ceramic
coating on the article upon contact therewith, and wherein the
ceramic coating comprises one or more of Y.sub.3Al.sub.5O.sub.12,
Y.sub.4Al.sub.2O.sub.9, Er.sub.3Al.sub.5O.sub.12,
Gd.sub.3Al.sub.5O.sub.12, Nd.sub.2O.sub.3, or a ceramic compound
comprising Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2.
11. A method comprising: providing an article, the article
comprising a ceramic coating disposed thereon; feeding a liquid
precursor solution into a plasma spray deposition system; and
generating, with the plasma spray deposition system, a stream
directed toward the article, wherein the stream forms a second
ceramic coating on the first ceramic coating upon contact
therewith, and wherein at least one of the first or second ceramic
coatings comprises Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2.
12. The method of claim 11, wherein at least one of the first or
second ceramic coatings comprises a composition selected from:
50-75 mol % of Y.sub.2O.sub.3, 10-30 mol % of ZrO.sub.2, and 10-30
mol % of Al.sub.2O.sub.3; 40-100 mol % of Y.sub.2O.sub.3, 0-60 mol
% of ZrO.sub.2, and 0-10 mol % of Al.sub.2O.sub.3; 40-60 mol % of
Y.sub.2O.sub.3, 30-50 mol % of ZrO.sub.2, and 10-20 mol % of
Al.sub.2O.sub.3; 40-50 mol % of Y.sub.2O.sub.3, 20-40 mol % of
ZrO.sub.2, and 20-40 mol % of Al.sub.2O.sub.3; 70-90 mol % of
Y.sub.2O.sub.3, 0-20 mol % of ZrO.sub.2, and 10-20 mol % of
Al.sub.2O.sub.3; 60-80 mol % of Y.sub.2O.sub.3, 0-10 mol % of
ZrO.sub.2, and 20-40 mol % of Al.sub.2O.sub.3; or 40-60 mol % of
Y.sub.2O.sub.3, 0-20 mol % of ZrO.sub.2, and 30-40 mol % of
Al.sub.2O.sub.3.
13. The method of claim 11, wherein at least one of the first or
second ceramic coatings comprises Y.sub.2O.sub.3 and one or more of
ZrO.sub.2, Er.sub.2O.sub.3, Gd.sub.2O.sub.3, or SiO.sub.2.
14. The method of claim 11, wherein at least one of the first or
second ceramic coatings comprises 40-45 mol % of Y.sub.2O.sub.3,
0-10 mol % of ZrO.sub.2, 35-40 mol % of Er.sub.2O.sub.3, 5-10 mol %
of Gd.sub.2O.sub.3, and 5-15 mole % of SiO.sub.2.
15. The method of claim 11, wherein at least one of the first or
second ceramic coatings comprises one or more of
Y.sub.3Al.sub.5O.sub.12, Y.sub.4Al.sub.2O.sub.9,
Er.sub.3Al.sub.5O.sub.12, Gd.sub.3Al.sub.5O.sub.12,
Nd.sub.2O.sub.3, or a ceramic compound comprising
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2.
16. The method of claim 11, wherein at least one of the first or
second ceramic coatings ceramic coating comprises Y.sub.2O.sub.3
and YF.sub.3.
17. The method of claim 11, wherein at least one of the first or
second ceramic coatings has a thickness from about 20 micrometers
to about 500 micrometers.
18. The method of claim 11, wherein the second ceramic coating has
a surface roughness of the ceramic coating is from about 100
micro-inches to about 300 micro-inches.
19. The method of claim 11, wherein at least one of the first or
second ceramic coatings has a porosity of the ceramic coating is
less than about 1%.
20. The method of claim 11, wherein the article is a chamber
component selected from a group consisting of a substrate support
assembly, an electrostatic chuck, a ring, a chamber wall, a base, a
gas distribution plate, a showerhead, a liner, a liner kit, a
shield, a plasma screen, a flow equalizer, a cooling base, a
chamber viewport, a chamber lid, a nozzle, or a process kit ring.
Description
RELATED APPLICATIONS
[0001] This patent application is a continuation of U.S. patent
application Ser. No. 15/640,274, filed Jun. 30, 2017, which is a
divisional application of U.S. patent application Ser. No.
14/462,057, filed Aug. 18, 2014, which claims the benefit under 35
U.S.C. .sctn. 119(e) of U.S. Provisional Application No.
61/879,549, filed Sep. 18, 2013, each of which is incorporated by
reference herein in their entireties.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate, in general, to
ceramic coated articles and to a process for plasma spraying a
ceramic coating onto chamber components.
BACKGROUND
[0003] In the semiconductor industry, devices are fabricated by a
number of manufacturing processes producing structures of an
ever-decreasing size. Some manufacturing processes such as plasma
etch and plasma clean processes expose a substrate to a high-speed
stream of plasma to etch or clean the substrate. The plasma may be
highly corrosive, and may corrode processing chambers and other
surfaces that are exposed to the plasma. This corrosion may
generate particles, which frequently contaminate the substrate that
is being processed, contributing to device defects.
[0004] As device geometries shrink, susceptibility to defects
increases, and particle contaminant requirements become more
stringent. Accordingly, as device geometries shrink, allowable
levels of particle contamination may be reduced. To minimize
particle contamination introduced by plasma etch and/or plasma
clean processes, chamber materials have been developed that are
resistant to plasmas. Different materials provide different
material properties, such as plasma resistance, rigidity, flexural
strength, thermal shock resistance, and so on. Also, different
materials have different material costs. Accordingly, some
materials have superior plasma resistance, other materials have
lower costs, and still other materials have superior flexural
strength and/or thermal shock resistance.
BRIEF DESCRIPTION OF THE DRAWINGS
[0005] The present invention is illustrated by way of example, and
not by way of limitation, in the figures of the accompanying
drawings in which like references indicate similar elements. It
should be noted that different references to "an" or "one"
embodiment in this disclosure are not necessarily to the same
embodiment, and such references mean at least one.
[0006] FIG. 1 depicts a sectional view of one embodiment of a
processing chamber.
[0007] FIG. 2 illustrates an exemplary architecture of a
manufacturing system, in accordance with one embodiment of the
present invention.
[0008] FIG. 3 depicts a schematic of a plasma spray deposition
system.
[0009] FIG. 4 depicts a further schematic of a plasma spray
deposition system.
[0010] FIG. 5 illustrates one embodiment of a process for forming
multiple plasma sprayed ceramic coating over a chamber
component.
[0011] FIG. 6 illustrates a cross sectional side view of articles
covered by one or more plasma sprayed protective layers.
[0012] FIG. 7 illustrates a further cross sectional side view of
articles covered by one or more plasma sprayed protective
layers.
DETAILED DESCRIPTION OF EMBODIMENTS
[0013] Some embodiments of the disclosure are directed to a process
for forming a plasma resistant ceramic coating having a stack of at
least two protective layers on an article. The at least two
protective layers may have different thicknesses and/or densities
and are deposited using different plasma spray processes. The
processes disclosed herein provide improved plasma resistance
performance for chamber components.
[0014] In one embodiment, an article (e.g., a chamber component) is
inserted into a low pressure plasma spray chamber. A low pressure
plasma spray process is performed by a plasma spraying system to
form a first plasma resistant layer having a thickness of 100-200
microns and a porosity of over 1%. The plasma spraying system then
performs a plasma spray thin film (PSTF), plasma spray physical
vapor deposition (PSPVD) or plasma spray chemical vapor deposition
(PSCVD) process to deposit a second plasma resistant layer on the
first plasma resistant layer, the second plasma resistant layer
having a thickness of 1-50 microns and a porosity of less than 1%.
The PSTF, PSCVD or PSPVD plasma spray process may be performed by
the same low pressure plasma spray chamber that performs the low
pressure plasma spray process. Additionally, the PSTF, PSCVD or
PSPVD plasma spray process may be performed immediately after the
low pressure plasma spray process as part of a single deposition
recipe. Alternatively, the first plasma spray process may be an
atmospheric pressure plasma spray (APPS) process (also referred to
as an air plasma spray (APS) process. In such an embodiment, the
article would be placed into a low pressure plasma spray chamber to
perform the PSTF, PSCVD or PSPVD process after performing the APPS
process.
[0015] The ceramic coating of the article may be highly resistant
to plasma etching, and the article may have superior mechanical
properties such as a high flexural strength and a high thermal
shock resistance. Performance properties of the coated ceramic
article may include a high thermal capability, a long lifespan, and
a low on-wafer particle and metal contamination. Additionally, by
performing both the low pressure plasma spray process and the PSTF,
PSCVD or PSPVD plasma spray processes in the same low pressure
plasma spray chamber, cycle time and cost may be reduced.
[0016] When the terms "about" and "approximately" are used herein,
these are intended to mean that the nominal value presented is
precise within .+-.30%. The articles described herein may be
structures that are exposed to plasma, such as chamber components
for a plasma etcher (also known as a plasma etch reactor). For
example, the articles may be walls, bases, gas distribution plates,
rings, view ports, lids, nozzles, shower heads, substrate holding
frames, electrostatic chucks (ESCs), face plates, selectivity
modulation devices (SMDs), etc. of a plasma etcher, a plasma
cleaner, a plasma propulsion system, and so forth.
[0017] Moreover, embodiments are described herein with reference to
ceramic coated chamber components and other articles that may cause
reduced particle contamination when used in a process chamber for
plasma rich processes. However, it should be understood that the
ceramic coated articles discussed herein may also provide reduced
particle contamination when used in process chambers for other
processes such as non-plasma etchers, non-plasma cleaners, chemical
vapor deposition (CVD) chambers, physical vapor deposition (PVD)
chambers, and so forth. Moreover, some embodiments are described
with reference to specific plasma resistant ceramics. However, it
should be understood that embodiments equally apply to other plasma
resistant ceramics than those discussed herein.
[0018] FIG. 1 is a sectional view of a processing chamber 100
(e.g., a semiconductor processing chamber) having one or more
chamber components that are coated with a ceramic coating in
accordance with embodiments of the present invention. The
processing chamber 100 may be used for processes in which a
corrosive plasma environment is provided. For example, the
processing chamber 100 may be a chamber for a plasma etch reactor
(also known as a plasma etcher), a plasma cleaner, and so forth.
Examples of chamber components that may include a plasma resistant
ceramic coating include a substrate support assembly 148, an
electrostatic chuck (ESC) 150, a ring (e.g., a process kit ring or
single ring), a chamber wall, a base, a gas distribution plate, a
showerhead, a liner, a liner kit, a shield, a plasma screen, a flow
equalizer, a cooling base, a chamber viewport, a chamber lid, a
nozzle, process kit rings, and so on.
[0019] In one embodiment, the plasma resistant ceramic coating,
which is described in greater detail below, is a multi-layer rare
earth oxide coating deposited by a combination of a low pressure
plasma spraying (LPPS) process and one of a plasma spray thin film
(PSTF) process, a plasma spray chemical vapor deposition (PSCVD)
process or a plasma spray physical vapor deposition (PSPVD)
process. Alternatively, the plasma resistant ceramic coating may be
a multi-layer rare earth oxide coating deposited by a combination
of an atmospheric pressure plasma spray (APPS) process and one of a
PSTF, PSCVD or PSPVD process.
[0020] The plasma resistant ceramic coating may have multiple
plasma resistant layers, in accordance with embodiments. The
multiple layers may each have the same material composition or may
have different material compositions. Any of the layers of the
plasma resistant coating may include Y.sub.2O.sub.3 and
Y.sub.2O.sub.3 based ceramics, Y.sub.3Al.sub.5O.sub.12 (YAG),
Al.sub.2O.sub.3 (alumina), Y.sub.4Al.sub.2O.sub.9 (YAM), SiC
(silicon carbide) Si.sub.3N.sub.4 (silicon nitride), SiN (silicon
nitride), MN (aluminum nitride), TiO.sub.2 (titania), ZrO.sub.2
(zirconia), TiC (titanium carbide), ZrC (zirconium carbide), TiN
(titanium nitride), Y.sub.2O.sub.3 stabilized ZrO.sub.2 (YSZ),
Er.sub.2O.sub.3 and Er.sub.2O.sub.3 based ceramics, Gd.sub.2O.sub.3
and Gd.sub.2O.sub.3 based ceramics, Er.sub.3Al.sub.5O.sub.12 (EAG),
Gd.sub.3Al.sub.5O.sub.12 (GAG), Nd.sub.2O.sub.3 and Nd.sub.2O.sub.3
based ceramics, and/or a ceramic compound comprising
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2.
[0021] Any of the layers of the plasma resistant ceramic coating
may also be based on a solid solution formed by any of the
aforementioned ceramics. With reference to the ceramic compound
comprising Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2, in one embodiment the ceramic compound
includes 62.93 molar ratio (mol %) Y.sub.2O.sub.3, 23.23 mol %
ZrO.sub.2 and 13.94 mol % Al.sub.2O.sub.3. In another embodiment,
the ceramic compound can include Y.sub.2O.sub.3 in a range of 50-75
mol %, ZrO.sub.2 in a range of 10-30 mol % and Al.sub.2O.sub.3 in a
range of 10-30 mol %. In another embodiment, the ceramic compound
can include Y.sub.2O.sub.3 in a range of 40-100 mol %, ZrO.sub.2 in
a range of 0-60 mol % and Al.sub.2O.sub.3 in a range of 0-10 mol %.
In another embodiment, the ceramic compound can include
Y.sub.2O.sub.3 in a range of 40-60 mol %, ZrO.sub.2 in a range of
30-50 mol % and Al.sub.2O.sub.3 in a range of 10-20 mol %. In
another embodiment, the ceramic compound can include Y.sub.2O.sub.3
in a range of 40-50 mol %, ZrO.sub.2 in a range of 20-40 mol % and
Al.sub.2O.sub.3 in a range of 20-40 mol %. In another embodiment,
the ceramic compound can include Y.sub.2O.sub.3 in a range of 70-90
mol %, ZrO.sub.2 in a range of 0-20 mol % and Al.sub.2O.sub.3 in a
range of 10-20 mol %. In another embodiment, the ceramic compound
can include Y.sub.2O.sub.3 in a range of 60-80 mol %, ZrO.sub.2 in
a range of 0-10 mol % and Al.sub.2O.sub.3 in a range of 20-40 mol
%. In another embodiment, the ceramic compound can include
Y.sub.2O.sub.3 in a range of 40-60 mol %, ZrO.sub.2 in a range of
0-20 mol % and Al.sub.2O.sub.3 in a range of 30-40 mol %. In other
embodiments, other distributions may also be used for the ceramic
compound.
[0022] In one embodiment, an alternative ceramic compound that
includes a combination of Y.sub.2O.sub.3, ZrO.sub.2,
Er.sub.2O.sub.3, Gd.sub.2O.sub.3 and SiO.sub.2 is used for one or
more layers of the plasma resistant ceramic coating. In one
embodiment, the alternative ceramic compound can include
Y.sub.2O.sub.3 in a range of 40-45 mol %, ZrO.sub.2 in a range of
0-10 mol %, Er2O3 in a range of 35-40 mol %, Gd.sub.2O.sub.3 in a
range of 5-10 mol % and SiO2 in a range of 5-15 mol %. In a first
example, the alternative ceramic compound includes 40 mol %
Y.sub.2O.sub.3, 5 mol % ZrO.sub.2, 35 mol % Er.sub.2O.sub.3, 5 mol
% Gd.sub.2O.sub.3 and 15 mol % SiO.sub.2. In a second example, the
alternative ceramic compound includes 45 mol % Y.sub.2O.sub.3, 5
mol % ZrO.sub.2, 35 mol % Er.sub.2O.sub.3, 10 mol % Gd.sub.2O.sub.3
and 5 mol % SiO.sub.2. In a third example, the alternative ceramic
compound includes 40 mol % Y.sub.2O.sub.3, 5 mol % ZrO.sub.2, 40
mol % Er.sub.2O.sub.3, 7 mol % Gd.sub.2O.sub.3 and 8 mol %
SiO.sub.2.
[0023] Any of the aforementioned plasma resistant ceramic coatings
may include trace amounts of other materials such as ZrO.sub.2,
Al.sub.2O.sub.3, SiO.sub.2, B.sub.2O.sub.3, Er.sub.2O.sub.3,
Nd.sub.2O.sub.3, Nb.sub.2O.sub.5, CeO.sub.2, Sm.sub.2O.sub.3,
Yb.sub.2O.sub.3, or other oxides. The ceramic coating allows for
longer working lifetimes due to the plasma resistance of the
ceramic coating and decreased on-wafer or substrate contamination.
Beneficially, in some embodiments the ceramic coating may be
stripped and re-coated without affecting the dimensions of the
substrates that are coated.
[0024] In one embodiment, the processing chamber 100 includes a
chamber body 102 and a lid 130 that enclose an interior volume 106.
The lid 130 may have a hole in its center, and a nozzle 132 may be
inserted into the hole. The chamber body 102 may be fabricated from
aluminum, stainless steel or other suitable material. The chamber
body 102 generally includes sidewalls 108 and a bottom 110.
Sidewalls 108 and/or bottom 110 may include a plasma resistant
ceramic coating.
[0025] An outer liner 116 may be disposed adjacent the sidewalls
108 to protect the chamber body 102. The outer liner 116 may be
fabricated and/or coated with a plasma resistant ceramic coating.
In one embodiment, the outer liner 116 is fabricated from aluminum
oxide.
[0026] An exhaust port 126 may be defined in the chamber body 102,
and may couple the interior volume 106 to a pump system 128. The
pump system 128 may include one or more pumps and throttle valves
utilized to evacuate and regulate the pressure of the interior
volume 106 of the processing chamber 100.
[0027] The lid 130 may be supported on the sidewall 108 of the
chamber body 102. The lid 130 may be opened to allow access to the
interior volume 106 of the processing chamber 100, and may provide
a seal for the processing chamber 100 while closed. A gas panel 158
may be coupled to the processing chamber 100 to provide process
and/or cleaning gases to the interior volume 106 through the nozzle
132. The lid 130 may be a ceramic such as Al.sub.2O.sub.3,
Y.sub.2O.sub.3, YAG, SiO.sub.2, AlN, SiN, SiC, Si--SiC, or a
ceramic compound comprising Y.sub.4Al.sub.2O.sub.9 and a
solid-solution of Y.sub.2O.sub.3--ZrO.sub.2. The nozzle 132 may
also be a ceramic, such as any of those ceramics mentioned for the
lid. The lid 130 may include a plasma resistant ceramic coating
133. The nozzle 132 may be coated with a plasma resistant ceramic
coating 134.
[0028] Examples of processing gases that may be used to process
substrates in the processing chamber 100 include halogen-containing
gases, such as C.sub.2F.sub.6, SF.sub.6, SiCl.sub.4, HBr, NF.sub.3,
CF.sub.4, CHF.sub.3, CH.sub.2F.sub.3, F, NF.sub.3, Cl.sub.2,
CCl.sub.4, BCl.sub.3 and SiF.sub.4, among others, and other gases
such as O.sub.2, or N.sub.2O. Examples of carrier gases include
N.sub.2, He, Ar, and other gases inert to process gases (e.g.,
non-reactive gases). A substrate support assembly 148 is disposed
in the interior volume 106 of the processing chamber 100 below the
lid 130. The substrate support assembly 148 holds a substrate 144
during processing. A ring 146 (e.g., a single ring) may cover a
portion of the electrostatic chuck 150, and may protect the covered
portion from exposure to plasma during processing. The ring 146 may
be silicon or quartz in one embodiment. The ring 146 may include a
plasma resistant ceramic coating.
[0029] An inner liner 118 may be coated on the periphery of the
substrate support assembly 148. The inner liner 118 may be a
halogen-containing gas resist material such as those discussed with
reference to the outer liner 116. In one embodiment, the inner
liner 118 may be fabricated from the same materials of the outer
liner 116. Additionally, the inner liner 118 may be coated with a
plasma resistant ceramic coating.
[0030] In one embodiment, the substrate support assembly 148
includes a mounting plate 162 supporting a pedestal 152, and an
electrostatic chuck 150. The electrostatic chuck 150 further
includes a thermally conductive base 164 and an electrostatic puck
166 bonded to the thermally conductive base by a bond 138, which
may be a silicone bond in one embodiment. The mounting plate 162 is
coupled to the bottom 110 of the chamber body 102 and includes
passages for routing utilities (e.g., fluids, power lines, sensor
leads, etc.) to the thermally conductive base 164 and the
electrostatic puck 166.
[0031] The electrostatic puck 166 may include a plasma resistant
ceramic coating. The thermally conductive base 164 and/or
electrostatic puck 166 may include one or more optional embedded
heating elements 176, embedded thermal isolators 174 and/or
conduits 168, 170 to control a lateral temperature profile of the
substrate support assembly 148. The conduits 168, 170 may be
fluidly coupled to a fluid source 172 that circulates a temperature
regulating fluid through the conduits 168, 170. The embedded
isolators 174 may be disposed between the conduits 168, 170 in one
embodiment. The optional embedded heating elements 176 is regulated
by a heater power source 178. The conduits 168, 170 and optional
embedded heating elements 176 may be utilized to control the
temperature of the thermally conductive base 164, thereby heating
and/or cooling the electrostatic puck 166 and a substrate (e.g., a
wafer) 144 being processed. The temperature of the electrostatic
puck 166 and the thermally conductive base 164 may be monitored
using a plurality of temperature sensors 190, 192, which may be
monitored using a controller 195.
[0032] The electrostatic puck 166 may further include multiple gas
passages such as grooves, mesas and other surface features that may
be formed in an upper surface of the electrostatic puck 166. The
gas passages may be fluidly coupled to a source of a heat transfer
(or backside) gas such as He via holes drilled in the electrostatic
puck 166. In operation, the backside gas may be provided at
controlled pressure into the gas passages to enhance the heat
transfer between the electrostatic puck 166 and the substrate
144.
[0033] The electrostatic puck 166 includes at least one clamping
electrode 180 controlled by a chucking power source 182. The at
least one clamping electrode 180 (or other electrode disposed in
the electrostatic puck 166 or thermally conductive base 164) may
further be coupled to one or more RF power sources 184, 186 through
a matching circuit 188 for maintaining a plasma formed from process
and/or other gases within the processing chamber 100. The one or
more RF power sources 184, 186 are generally capable of producing
RF signal having a frequency from about 50 kHz to about 3 GHz and a
power of up to about 10,000 Watts.
[0034] FIG. 2 illustrates an exemplary architecture of a
manufacturing system 200. The manufacturing system 200 may be a
ceramics manufacturing system. In one embodiment, the manufacturing
system 200 includes manufacturing machines 201 (e.g., processing
equipment) connected to an equipment automation layer 215. The
manufacturing machines 201 may include a bead blaster 202, one or
more wet cleaners 203, and/or a plasma spraying system 204. The
manufacturing system 200 may further include one or more computing
device 220 connected to the equipment automation layer 215. In
alternative embodiments, the manufacturing system 200 may include
more or fewer components. For example, the manufacturing system 200
may include manually operated (e.g., off-line) manufacturing
machines 201 without the equipment automation layer 215 or the
computing device 220.
[0035] Bead blaster 202 is a machine configured to roughen the
surface of articles such as articles. Bead blaster 202 may be a
bead blasting cabinet, a hand held bead blaster, or other type of
bead blaster. Bead blaster 202 may roughen a substrate by
bombarding the substrate with beads or particles. In one
embodiment, bead blaster 202 fires ceramic beads or particles at
the substrate. The roughness achieved by the bead blaster 202 may
be based on a force used to fire the beads, bead materials, bead
sizes, distance of the bead blaster from the substrate, processing
duration, and so forth. In one embodiment, the bead blaster uses a
range of bead sizes to roughen the ceramic article.
[0036] In alternative embodiments, other types of surface
rougheners than a bead blaster 202 may be used. For example, a
motorized abrasive pad may be used to roughen the surface of
ceramic substrates. A sander may rotate or vibrate the abrasive pad
while the abrasive pad is pressed against a surface of the article.
A roughness achieved by the abrasive pad may depend on an applied
pressure, on a vibration or rotation rate and/or on a roughness of
the abrasive pad.
[0037] Wet cleaners 203 are cleaning apparatuses that clean
articles (e.g., articles) using a wet clean process. Wet cleaners
203 include wet baths filled with liquids, in which the substrate
is immersed to clean the substrate. Wet cleaners 203 may agitate
the wet bath using ultrasonic waves during cleaning to improve a
cleaning efficacy. This is referred to herein as sonicating the wet
bath.
[0038] In other embodiments, alternative types of cleaners such as
dry cleaners may be used to clean the articles. Dry cleaners may
clean articles by applying heat, by applying gas, by applying
plasma, and so forth.
[0039] Plasma spraying system 204 is a machine configured to plasma
spray a ceramic coating to the surface of a substrate. Plasma
spraying systems are discussed in greater detail with reference to
FIGS. 3-4.
[0040] The equipment automation layer 215 may interconnect some or
all of the manufacturing machines 201 with computing devices 220,
with other manufacturing machines, with metrology tools and/or
other devices. The equipment automation layer 215 may include a
network (e.g., a location area network (LAN)), routers, gateways,
servers, data stores, and so on. Manufacturing machines 201 may
connect to the equipment automation layer 215 via a SEMI Equipment
Communications Standard/Generic Equipment Model (SECS/GEM)
interface, via an Ethernet interface, and/or via other interfaces.
In one embodiment, the equipment automation layer 215 enables
process data (e.g., data collected by manufacturing machines 201
during a process run) to be stored in a data store (not shown). In
an alternative embodiment, the computing device 220 connects
directly to one or more of the manufacturing machines 201.
[0041] In one embodiment, some or all manufacturing machines 201
include a programmable controller that can load, store and execute
process recipes. The programmable controller may control
temperature settings, gas and/or vacuum settings, time settings,
etc. of manufacturing machines 201. The programmable controller may
include a main memory (e.g., read-only memory (ROM), flash memory,
dynamic random access memory (DRAM), static random access memory
(SRAM), etc.), and/or a secondary memory (e.g., a data storage
device such as a disk drive). The main memory and/or secondary
memory may store instructions for performing heat treatment
processes described herein.
[0042] The programmable controller may also include a processing
device coupled to the main memory and/or secondary memory (e.g.,
via a bus) to execute the instructions. The processing device may
be a general-purpose processing device such as a microprocessor,
central processing unit, or the like. The processing device may
also be a special-purpose processing device such as an application
specific integrated circuit (ASIC), a field programmable gate array
(FPGA), a digital signal processor (DSP), network processor, or the
like. In one embodiment, programmable controller is a programmable
logic controller (PLC).
[0043] In one embodiment, the manufacturing machines 201 are
programmed to execute recipes that will cause the manufacturing
machines to roughen a substrate, clean a substrate and/or article,
coat a article and/or machine (e.g., grind or polish) a article. In
one embodiment, the manufacturing machines 201 are programmed to
execute recipes that perform operations of a multi-step process for
manufacturing a ceramic coated article, as described with reference
to FIG. 5. The computing device 220 may store one or more ceramic
coating recipes 225 that can be downloaded to the manufacturing
machines 201 to cause the manufacturing machines 201 to manufacture
ceramic coated articles in accordance with embodiments of the
present disclosure.
[0044] FIGS. 3-4 illustrate an LPPS system 300 for plasma spraying
a multi-layer plasma resistant ceramic coating on a chamber
component or other article used in a corrosive system. The LPPS
system 300 is a plasma spray system that includes a vacuum chamber
301 that can be pumped down to reduced pressure (e.g., to a vacuum
of 1 Mbar, 10 Mbar, 35 Mbar, etc.). The LPPS system 300 may perform
LPPS processes, PSPVD processes, PSCVD processes and/or PSTF
processes.
[0045] In one embodiment (as illustrated), the LPPS system 300 is
used to deposit a porous, low density first protective layer 312
and a thinner dense second protective layer 313 over the first
protective layer 312. In an alternative embodiment, a conventional
atmospheric pressure plasma spray (APPS) system that operates at
atmospheric pressure is used to deposit the porous, low density
first protective layer 312, and the LPPS 300 is used to deposit the
thinner dense second protective layer 313 over the first protective
layer 312. An APPS system does not include any vacuum chamber, and
may instead include an open chamber or room.
[0046] In a plasma spray system, an arc is formed between two
electrodes through which a gas is flowing. Examples of gas suitable
for use in the low pressure plasma spray system 300 include, but
are not limited to, Argon/Hydrogen or Argon/Helium. As the gas is
heated by the arc, the gas expands and is accelerated through a
shaped nozzle of a plasma torch 304, creating a high velocity
plasma jet 302.
[0047] FIG. 3 shows deposition of the first protective layer 312 by
the LPPS system 300 using an LPPS process. Powder 309 composed of a
ceramic and/or metal material is injected into the plasma jet 302
by a powder delivery system 308. An intense temperature of the
plasma jet 302 melts the powder 309 and propels the molten ceramic
and/or metal material towards an article 310. Upon impacting with
the article 310, the molten powder flattens, rapidly solidifies,
and forms a first protective layer 312 of a ceramic coating. The
molten powder adheres to the article 310. The parameters that
affect the thickness, density, and roughness of the first
protective layer 312 of the ceramic coating include type of powder,
powder size distribution, powder feed rate, plasma gas composition,
gas flow rate, energy input, pressure, and torch offset distance.
In one embodiment, the LPPS system 300 performs an LPPS process to
form the first protective layer 312 having a thickness of up to 50
microns. In another embodiment, the first protective layer 312
formed by the LPPS process has a thickness of up to 500
microns.
[0048] For LPPS processes, a chamber pressure of around 20-200 mbar
may be used to produce coatings on the order of 20-500 microns.
LPPS typically has a high velocity plasma jet flow. For LPPS,
thermal energy of the plasma gas is converted to kinetic energy by
the expansion of volume in the low pressure environment. LPPS
processes may produce ceramic coatings with a porosity of about
1-5%. For LPPS, metallurgical bonding or diffusion bonding is a
dominant bonding mechanism.
[0049] In one embodiment, the first protective layer 312 is formed
by an APPS system performing an APPS process. In one embodiment,
the first protective layer 312 formed ty the APPS process has a
thickness of approximately 20-500 microns. Alternatively, the first
protective layer 312 may have other thicknesses. An APPS process
may produce ceramic coatings having thicknesses of around 20
microns to several millimeters. The APPS process produces an oxide
ceramic coating having a relatively high porosity. For example,
APPS processes may produce ceramic coatings with a porosity of 1-5%
in some embodiments. In some embodiments, APPS may produce ceramic
coatings with a porosity of up to about 10%. For APPS, the ceramic
coating bonds to the substrate mainly by mechanical bonding. As
compared to LPPS, APPS typically has a lower velocity plasma jet
flow with a higher temperature.
[0050] FIG. 4 shows deposition of the second protective layer 313
by the LPPS system 300 using one of a PSPVD, PSTF or PSCVD process.
Feedstock 320 composed of a ceramic and/or metal material is
injected into the plasma jet 302 by a feedstock delivery system
315. For PSPVD and PSTF processes, the feedstock is a powder
composed of a ceramic and/or metal material. Accordingly, if a
PSPVD process or PSTF process are to be performed, then feedstock
320 may correspond to powder 309 and feedstock delivery system 315
may correspond to powder delivery system 308. Moreover, if the
second protective layer 313 is to have the same material
composition of the first protective layer 312, then the same powder
309 may be used to perform both the first protective layer 312 and
the second protective layer 313. For PSCVD processes, the feedstock
is a liquid or vapor. Accordingly, if a PSCVD process is to be
performed, then a different feedstock is used for the second
protective layer 313 and the first protective layer 312, even if
the two protective layers are to have the same material
composition.
[0051] For PSCVD, PSTF and PSPVD processes, an intense temperature
of the plasma jet 302 melts or vaporizes the feedstock 320 and
propels the molten or vapor ceramic and/or metal material towards
article 310. Upon impacting with the first protective layer 312,
the molten powder flattens, rapidly solidifies, and forms a first
protective layer 312 of a ceramic coating. Alternatively, upon
impacting the first protective layer 312 the vaporized powder
changes phase to a solid and forms the second protective layer 313
of the ceramic coating. The molten or vaporized powder adheres to
the first protective layer 312. The parameters that affect the
thickness, density, and roughness of the second protective layer
313 of the ceramic coating include type of feedstock, powder size
distribution (if the feedstock is a powder), a feed rate, plasma
gas composition, gas flow rate for the plasma, energy input,
pressure, and torch offset distance.
[0052] In one embodiment, the LPPS system 300 performs a PSPVD
process to form the second protective layer 313 having a thickness
of 10-100 microns. PSPVD refers to a plasma spray process in which
powder feedstock is typically vaporized and deposition occurs
primarily from the vapor phase. Alternatively, PSPVD may melt
powder feedstock to produce liquid splats that build up to form the
second protective layer 313. For PSPVD processes, a chamber
pressure of around 0.1-50 mbar may be used to produce dense
coatings using high gun enthalpy to vaporize or melt ceramic
feedstock material. The ceramic coatings produced by PSPVD have a
uniform thickness.
[0053] In one embodiment, the LPPS system 300 performs a PSTF
process to form the second protective layer 313 having a thickness
of 10-100 microns. PSTF refers to a process with powder feedstock
where deposition is predominantly by molten droplets, similar to
conventional plasma spray but at greatly reduced chamber pressures.
For PSTF processes, a pressure of around 0.1-50 mbar may be used to
produce thin dense coatings from liquid splats using a classical
thermal spray approach but at high velocity and enthalpy. PSTF
processes are performed by spraying particles at high velocities
(e.g., 400-800 meters per second (m/s) and high enthalpy (e.g.,
8000-15,000 kJ/kg). The ceramic coatings produced by PSTF have a
uniform thickness with minimal internal stresses.
[0054] In one embodiment, the LPPS system 300 performs a PSCVD
process to form the second protective layer 313 having a thickness
of approximately 1 to 50 microns. PSCVD refers to a plasma spray
process in which an extremely low pressure of less than 1 mbar
(e.g., around 0.3-1.0 mbar) and a relatively low power of less than
10 kW are used to produce thin dense coatings having a thickness of
less than 50 microns. The feedstock for PSCVD processes is liquid
or gaseous precursors. The ceramic coatings produced by PSCVD have
a uniform thickness.
[0055] FIG. 5 illustrates one embodiment of a process for forming
multiple plasma sprayed protective layers over a chamber component.
At block 502, an LPPS or APPS process is selected for plasma
spraying a first plasma resistant layer. At block 504, an article
(e.g., a substrate) is prepared for coating. The article may be a
metal substrate such as aluminum, copper, magnesium, or another
metal or a metal alloy. The article may also be a ceramic
substrate, such as alumina, yttria, or another ceramic or a mixture
of ceramics. Preparing the article may include shaping the article
to a desired form, grinding, blasting or polishing the article to
provide a particular surface roughness and/or cleaning the article.
In one embodiment, the article is roughened. In another embodiment,
the article is not roughened prior to depositing the ceramic
coating.
[0056] At block 506, an article is placed into an APPS system or
into a vacuum chamber of an LPPS system depending on an outcome at
block 502. At block 508, optimal powder characteristics for plasma
spraying a ceramic coating using an LPPS or APPS process are
selected. In one embodiment, an optimized agglomerate powder size
distribution is selected where 10% of agglomerate powder (D10) has
a size of less than 10 .mu.m, 50% of agglomerate powder (D50) has a
size of 20-30 .mu.m and 90% of agglomerate powder (D90) has a size
of less than 55 .mu.m.
[0057] Raw ceramic powders having specified compositions, purity
and particle sizes are selected. The ceramic powder may be formed
of any of the rare earth oxides previously discussed. The raw
ceramic powders are then mixed. These raw ceramic powders may have
a purity of 99.9% or greater in one embodiment. The raw ceramic
powders may be mixed using, for example, ball milling. The raw
ceramic powders may have a powder size in a range of between about
100 nm-20 .mu.m. In one embodiment, the raw ceramic powders have a
powder size of approximately 5 .mu.m.
[0058] After the ceramic powders are mixed, they may be calcinated
at a specified calcination time and temperature. In one embodiment,
a calcination temperature of approximately 1200-2000.degree. C.
(e.g., 1400.degree. C. in one embodiment) and a calcination time of
approximately 2-5 hours (e.g., 3 hours in one embodiment) is used.
The spray dried granular particle size for the mixed powder may
have a size distribution of approximately 30 .mu.m in one
embodiment.
[0059] At block 510, optimal plasma spray parameters for plasma
spraying a ceramic coating using an LPPS or APPS process are
selected. The parameters may be adjusted to values falling within
the ranges shown in Table 3 based on a subsequent plasma spray
process to be performed. In one embodiment, optimizing plasma spray
parameters includes, but is not limited to, setting a plasma gun
power, chamber pressure and a composition of spray carrier gas.
Optimizing the powder characteristics and the plasma spray
parameters may lead to a coating with a decreased porosity and an
increased density and an increased percentage of fully melted
nodules. Such a decreased porosity and increased density improves
protection of a coated article from corrosive elements such as
plasmas. Also, fully melted nodules are less likely to break free
of the ceramic coating and contaminate the wafer causing particle
problems. In one embodiment, an optimal powder type and an optimal
powder size distribution are selected for the powder.
[0060] At block 512, the article is coated according to the
selected powder characteristics and plasma spray parameters to form
a first plasma resistant layer. LPPS and APPS processes may melt
materials (e.g., ceramic powders) and spray the melted materials
onto the article using the selected parameters. The first plasma
resistant layer may have a thickness of about 20-500 microns, and a
thickness of about 100-200 microns in a particular embodiment.
Additionally, the first plasma resistant layer may have a porosity
of 1-5%. In some instances, the first plasma resistant layer has a
porosity of around 3-5%.
[0061] The plasma spray process may be performed in multiple spray
passes. For each pass, the angle of a plasma spray nozzle may
change to maintain a relative angle to a surface that is being
sprayed. For example, the plasma spray nozzle may be rotated to
maintain an angle of approximately 45 degrees to approximately 90
degrees with the surface of the article being sprayed. Each pass
may deposit a thickness of up to approximately 25 .mu.m, depending
on the plasma spray process that is being performed and the input
parameters. The first plasma resistant layer may have a surface
roughness of about 100-300 micro-inches.
[0062] At block 514, a PSTF, PSCVD or PSPVD process is selected for
forming a second plasma resistant layer. At block 516, a
determination may be made as to whether the first plasma resistant
layer was formed using LPPS or APPS. If APPS was used for the first
plasma resistant layer, then the process continues to block 518,
and the article is loaded into a vacuum chamber of an LPPS system.
Otherwise the process proceeds to block 520, and the PSTF, PSCVD or
PSPVD process may be performed following the LPPS process.
[0063] At block 520, the plasma spray parameters are adjusted or
selected and/or the powder parameters are adjusted or selected to
optimize deposition using the PSTF, PSCVD or PSPVD process. For
example, if PSTF is to be performed, the pressure may be reduced to
approximately 0.1-50.0 Mbar. If PSPVD is to be performed, the
pressure may be reduced to approximately 0.1-50.0 Mbar, and the
plasma power may be unchanged or increased. If PSCVD is to be
performed, a liquid or vapor is supplied, pressure may be reduced
to less than about 0.4 Mbar, and plasma power is reduced to less
than about 10 kW. The parameters may be adjusted to values falling
within the ranges shown in Table 3 based on a subsequent plasma
spray process to be performed. For example, if an additional plasma
resistant layer is to be deposited using PSTF, then the plasma
spray parameters would be adjusted to within the ranges shown for
PSTF.
[0064] At block 522, the article is plasma sprayed using a PSTF,
PSPVD or PSCVD process to form a second plasma resistant layer.
PSCVD, PSPVD and/or PSTF processes may melt or vaporize materials
(e.g., ceramic powders, or liquid or gaseous precursors) and spray
the melted or vaporized materials onto the article using the
selected parameters. The second plasma resistant layer may have a
thickness of less than about 100 microns. In one embodiment, the
second plasma resistant layer has a thickness of approximately 10
microns or less. The second plasma resistant layer may be
conformal, uniform, and denser than the first plasma resistant
layer. In one embodiment, the second plasma resistant layer has a
porosity of less than 1%.
[0065] At block 524, it is determined whether to deposit any
additional layers for the plasma resistant ceramic coating. If an
additional layer is to be deposited, the process may return to
block 514 for plasma spraying another layer using a PSCVD, PSPVD or
PSTF process. Alternatively, the process may return to block 502,
506 or 508 for plasma spraying another layer using an APPS or LPPS
process. Otherwise the method ends.
TABLE-US-00001 TABLE 1 Plasma Spray Input Parameters Input LPPS
PSPVD PSTF APPS PSCVD Parameter Unit Range Range Range Range Range
Power of kW 9-300 9-300 9-300 9-300 <100 Plasma Gun Current A
300- 300- 300- 300- <1000 1000 1000 1000 1000 Gun Voltage V
30-300 30-300 30-300 30-300 <100 Powder Feed g/min. 5-200 5-200
5-200 5-200 5-200 Distance mm 500- 500- 500- 50-200 500- 3000 3000
3000 3000 Gas Flow L/min. 30-500 30-500 30-500 30-500 30-500 Rate
Pressure Mbar 10-100 0.1-50 0.1-50 1013 0.1-50
[0066] Table 1 illustrates input parameters that may be used for
coating the article using an LPPS process, a PSPVD process, a PSTF
process, an APPS process, or a PSCVD process. The parameters
include, but are not limited to, power of plasma, gun current, gun
voltage, powder feed rate, gun stand-off distance, gas flow rate
and chamber pressure.
[0067] FIGS. 6-7 illustrate cross sectional side views of articles
(e.g., chamber components) covered by plasma resistant ceramic
coatings including two or more protective layers. Referring to FIG.
6, a body 605 of the article 600 includes a plasma resistant
ceramic coating 606 having a first thick film protective layer 608
and a second thin film protective layer 610. In one embodiment, the
first thick film protective layer 608 is a plasma-sprayed layer
having a thickness of about 20-500 .mu.m and a porosity of about
1-5%. In one embodiment, the thin film protective layer is a
plasma-sprayed layer having a thickness of about 1-100 .mu.m and a
porosity of less than 1%. In one embodiment, the thick film
protective layer is deposited by LPPS and the thin film protective
layer is deposited by PSTF, PSCVD or PSPVD. In one embodiment, the
thick film protective layer is deposited by APPS, and the thin film
protective layer is deposited by one of PSTF, PSPVD or PSCVD.
[0068] Examples of ceramics that may be used to form the first
thick film protective layer 608 and thin film protective layer 610
include Y.sub.3Al.sub.5O.sub.12, Y.sub.4Al.sub.2O.sub.9,
Er.sub.2O.sub.3, Gd.sub.2O.sub.3, Er.sub.3Al.sub.5O.sub.12,
Gd.sub.3Al.sub.5O.sub.12, a ceramic compound comprising
Y.sub.4Al.sub.2O.sub.9 and a solid-solution of
Y.sub.2O.sub.3--ZrO.sub.2 (Y.sub.2O.sub.3--ZrO.sub.2 solid
solution), or any of the other ceramic materials previously
identified. Other Er based and/or Gd based plasma resistant rare
earth oxides may also be used to form the thick film protective
layer 608 and thin film protective layer 610. In one embodiment,
the same ceramic material is not used for two adjacent thin film
protective layers. However, in another embodiment adjacent layers
may be composed of the same ceramic.
[0069] FIG. 7 illustrates a cross sectional side view of another
embodiment of an article 700 having a plasma resistant ceramic
coating 706 that includes a stack of protective layers deposited
over a body 705 of the article 700. Article 700 is similar to
article 700, except that plasma resistant ceramic coating 706 has
four protective layers 708, 710, 715, 718. As shown, the protective
layers may be alternating thick film protective layers and thin
film protective layers. Alternatively, multiple thick film
protective layers may be deposited followed by a final thin film
protective layer. Thick film protective layers may be deposited by
LPPS or APPS and have a thickness of 20-500 microns. Thin film
protective layers may be deposited by PSTF, PSPVD or PSCVD and have
a thickness of 1-100 microns. The plasma resistant ceramic coating
706 may have any number of protective layers.
[0070] In one embodiment, the bottom protective layers 608, 708
include a coloring agent that will cause the deposited protective
layer to have a particular color. Examples of coloring agents that
may be used include Nd.sub.2O.sub.3, Sm.sub.2O.sub.3 and
Er.sub.2O.sub.3. Other coloring agents may also be used.
Accordingly, when the second protective layer 610, 710 wears away,
an operator may have a visual queue that it is time to refurbish or
exchange the article 600, 700.
[0071] The preceding description sets forth numerous specific
details such as examples of specific systems, components, methods,
and so forth, in order to provide a good understanding of several
embodiments of the present disclosure. It will be apparent to one
skilled in the art, however, that at least some embodiments of the
present disclosure may be practiced without these specific details.
In other instances, well-known components or methods are not
described in detail or are presented in simple block diagram format
in order to avoid unnecessarily obscuring the present disclosure.
Thus, the specific details set forth are merely exemplary.
Particular implementations may vary from these exemplary details
and still be contemplated to be within the scope of the present
disclosure.
[0072] Reference throughout this specification to "one embodiment"
or "an embodiment" means that a particular feature, structure, or
characteristic described in connection with the embodiment is
included in at least one embodiment. Thus, the appearances of the
phrase "in one embodiment" or "in an embodiment" in various places
throughout this specification are not necessarily all referring to
the same embodiment. In addition, the term "or" is intended to mean
an inclusive "or" rather than an exclusive "or."
[0073] Although the operations of the methods herein are shown and
described in a particular order, the order of the operations of
each method may be altered so that certain operations may be
performed in an inverse order or so that certain operation may be
performed, at least in part, concurrently with other operations. In
another embodiment, instructions or sub-operations of distinct
operations may be in an intermittent and/or alternating manner.
[0074] It is to be understood that the above description is
intended to be illustrative, and not restrictive. Many other
embodiments will be apparent to those of skill in the art upon
reading and understanding the above description. The scope of the
disclosure should, therefore, be determined with reference to the
appended claims, along with the full scope of equivalents to which
such claims are entitled.
* * * * *