U.S. patent application number 15/817080 was filed with the patent office on 2018-04-05 for flouride glazes from flourine ion treatment.
The applicant listed for this patent is Applied Materials, Inc.. Invention is credited to Chengtsin Lee, Jennifer Y. Sun.
Application Number | 20180093919 15/817080 |
Document ID | / |
Family ID | 59958580 |
Filed Date | 2018-04-05 |
United States Patent
Application |
20180093919 |
Kind Code |
A1 |
Lee; Chengtsin ; et
al. |
April 5, 2018 |
FLOURIDE GLAZES FROM FLOURINE ION TREATMENT
Abstract
An article comprises a body having a coating. The coating
comprising a mixture of a first oxide and a second oxide. The
coating includes a glaze on a surface of the coating, the glaze
comprising a eutectic system having a super-lattice of a first
fluoride and a second fluoride.
Inventors: |
Lee; Chengtsin; (Union City,
CA) ; Sun; Jennifer Y.; (Mountain View, CA) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
Applied Materials, Inc. |
Santa Clara |
CA |
US |
|
|
Family ID: |
59958580 |
Appl. No.: |
15/817080 |
Filed: |
November 17, 2017 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
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15418615 |
Jan 27, 2017 |
9850161 |
|
|
15817080 |
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|
62314750 |
Mar 29, 2016 |
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C03C 2217/214 20130101;
C03C 2218/13 20130101; C03C 2209/00 20130101; C03C 17/22 20130101;
C03C 21/007 20130101; C03C 8/06 20130101; C03C 17/245 20130101;
C03C 4/18 20130101; C03C 10/16 20130101; C03C 2204/00 20130101;
C03C 10/00 20130101; C03C 2217/285 20130101 |
International
Class: |
C03C 17/22 20060101
C03C017/22; C03C 10/00 20060101 C03C010/00; C03C 10/16 20060101
C03C010/16; C03C 8/06 20060101 C03C008/06; C03C 4/18 20060101
C03C004/18; C03C 17/245 20060101 C03C017/245 |
Claims
1. An article comprising: a body; a coating on the body, the
coating comprising a mixture of a first oxide of a first metal and
a second oxide of a second metal; and a glaze on a surface of the
coating, the glaze comprising a eutectic system having a
super-lattice of a first fluoride of the first metal and a second
fluoride of the second metal.
2. The article of claim 1, wherein the coating has a first
thickness of approximately 1 to 200 microns.
3. The article of claim 2, wherein the glaze has a second thickness
that is 50% to 100% of the first thickness.
4. The article of claim 1, wherein the first metal and the second
metal are selected from a group consisting of Nd, La, Er, Sc, Ti,
Zr, Hf, Al, Si and Y.
5. The article of claim 4, wherein the first oxide and the second
oxide are selected from a group consisting of Nd.sub.2O.sub.3,
La.sub.2O.sub.3, Er.sub.2O.sub.3, Sc.sub.2O.sub.3, TiO.sub.2,
ZrO.sub.2, HfO.sub.2, Al.sub.2O.sub.3 and SiO.sub.2, and
Y.sub.2O.sub.3.
6. The article of claim 4, wherein the first fluoride and the
second fluoride are selected from a group consisting of NdF.sub.3,
LaF.sub.3, ErF.sub.3, ScF.sub.3, TiF.sub.3, ZrF.sub.4, HfF.sub.4,
AlF.sub.3, SiF.sub.4 and YF.sub.3.
7. The article of claim 1, wherein the article comprises a sintered
ceramic article.
8. The article of claim 1, wherein the glaze has a thickness of 0.5
to 200 microns.
9. The article of claim 1, wherein the first oxide is ZrO.sub.2 and
the second oxide is Y.sub.2O.sub.3.
10. The article of claim 1, wherein the mixture of the first oxide
of the first metal and the second oxide of the second metal
comprises 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. The article of claim 1, wherein the mixture comprises the first
oxide of the first metal, the second oxide of the second metal, and
a third oxide of a rare earth, and wherein the eutectic system has
a super-lattice of the first fluoride, the second fluoride and a
third fluoride of the rare earth.
12. An article comprising: a ceramic body comprising a mixture of a
first oxide of a first metal and a second oxide of a second metal;
and a glaze on a surface of the article, the glaze comprising a
eutectic system having a super-lattice of a first fluoride of the
first metal and a second fluoride of the second metal.
13. The article of claim 12, wherein the first metal and the second
metal are selected from a group consisting of Nd, La, Er, Sc, Ti,
Zr, Hf, Al, Si and Y.
14. The article of claim 13, wherein the first oxide and the second
oxide are selected from a group consisting of Nd.sub.2O.sub.3,
La.sub.2O.sub.3, Er.sub.2O.sub.3, Sc.sub.2O.sub.3, TiO.sub.2,
ZrO.sub.2, HfO.sub.2, Al.sub.2O.sub.3 and SiO.sub.2, and
Y.sub.2O.sub.3.
15. The article of claim 13, wherein the first fluoride and the
second fluoride are selected from a group consisting of NdF.sub.3,
LaF.sub.3, ErF.sub.3, ScF.sub.3, TiF.sub.3, ZrF.sub.4, HfF.sub.4,
AlF.sub.3, SiF.sub.4 and YF.sub.3.
16. The article of claim 12, wherein the glaze has a thickness of
0.5 to 200 microns.
17. The article of claim 12, wherein the first oxide is ZrO.sub.2
and the second oxide is Y.sub.2O.sub.3.
18. The article of claim 12, wherein the mixture of the first oxide
of the first metal and the second oxide of the second metal
comprises a ceramic compound comprising Y.sub.4Al.sub.2O.sub.9 and
a solid-solution of Y.sub.2O.sub.3--ZrO.sub.2.
19. The article of claim 12, wherein the first fluoride is YF.sub.3
and the second fluoride is ZrF.sub.4.
20. The article of claim 12, wherein the mixture comprises the
first oxide of the first metal, the second oxide of the second
metal, and a third oxide of a rare earth, and wherein the eutectic
system has a super-lattice of the first fluoride, the second
fluoride and a third fluoride of the rare earth.
Description
RELATED APPLICATIONS
[0001] This patent application is a divisional of U.S. patent
application Ser. No. 15/418,615, filed Jan. 27, 2017, which claims
the benefit under 35 U.S.C. .sctn. 119(e) of U.S. Provisional
Application No. 62/314,750, filed Mar. 29, 2016, both of which are
herein incorporated by reference.
TECHNICAL FIELD
[0002] Embodiments of the present disclosure relate, in general, to
a method for creating a glass ceramic or a glaze from a eutectic
system of fluorides, and to glass ceramics and glazes formed from
the eutectic system of fluorides.
BACKGROUND
[0003] Various manufacturing processes expose chamber components
and their coating materials to high temperatures, high energy
plasma, a mixture of corrosive gases, high stress, and combinations
thereof. Rare earth oxides are frequently used in chamber component
manufacturing due to their resistance to erosion from plasma etch
chemistries. However, these rare earth oxide components transform
into fluorides during processing of wafers from exposure to
fluorine based chemistries. The transformation of the rare earth
oxide into a rare earth fluoride is usually combined with a volume
expansion and added stress. For example, the transformation of one
mole of Y.sub.2O.sub.3 (yttria) to two moles of YF.sub.3 (yttrium
fluoride) has a theoretical volume expansion of about 60%. The
volume expansion and added stress caused by conversion of a rare
earth oxide into a rare earth fluoride can the chamber components
to be responsible for particle defects by shedding particles onto
processed wafers.
[0004] In some instances YF.sub.3 has been used as a coating for
chamber components. However, YF.sub.3 has a high melting
temperature of 1400.degree. C. and fluoride is unstable at high
temperatures (e.g., temperatures above about 1000.degree. C.).
Additionally, glazes formed of YF.sub.3 are susceptible to cracking
and formation of bubbles. Accordingly, it can be difficult to
effectively form glazes of YF.sub.3 coatings.
SUMMARY
[0005] In an example implementation of a first method for forming a
glaze or a glass ceramic, a first fluoride having a first melting
temperature is mixed with a second fluoride having a second melting
temperature that is lower than the first melting temperature to
form a mixture comprising the first fluoride and the second
fluoride. The first fluoride and the second fluoride are melted by
heating the mixture of the first fluoride and the second fluoride
to a first temperature above at least the second melting
temperature. The mixture is cooled to form a material comprising a
eutectic system having a super-lattice of the first fluoride and
the second fluoride, wherein the eutectic system has a third
melting temperature that is below the first melting temperature and
the second melting temperature. The material is ground into a
powder. An article or a coating is then formed using the powder.
The article or coating is heated to a second temperature that is
below the first melting temperature, below the second melting
temperature and above the third melting temperature to cause at
least a portion of the article or the coating to transform into at
least one of a glaze or a glass ceramic comprising the eutectic
system.
[0006] In an example implementation of a second method for forming
a glaze, an article or coating comprising an initial mixture
including a first oxide and a second oxide is formed. The article
or coating is heated to a treatment temperature of at least
910.degree. C. The article or coating is exposed to anhydrous
hydrogen fluoride gas at the treatment temperature of at least
910.degree. C. Oxygen molecules in the first oxide and the second
oxide are replaced with fluorine molecules at a surface of the
article or the coating. The initial mixture comprising the first
oxide and the second oxide is transformed into a final mixture
comprising a first fluoride and a second fluoride at the surface of
the article or the coating. A eutectic system is formed from the
final mixture at the surface of the article or the coating, the
eutectic system having a super-lattice of the first fluoride and
the second fluoride. A glaze is then formed from the eutectic
system at the surface of the article or the coating.
[0007] In another example implementation an article comprises a
body having a coating on the body. The coating comprising a
eutectic system having a super-lattice of a first fluoride and a
second fluoride. The coating further comprises a glaze on a surface
of the coating, the glaze comprising the eutectic system having the
super-lattice of the first fluoride and the second fluoride. The
coating may have been formed in accordance with the first method or
the second method.
BRIEF DESCRIPTION OF THE DRAWINGS
[0008] The present disclosure 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.
[0009] FIG. 1 illustrates an exemplary architecture of a
manufacturing system, in accordance with one embodiment of the
present invention;
[0010] FIG. 2 illustrates a process for manufacturing a coating or
article from a mixture of multiple fluorides according to an
embodiment.
[0011] FIG. 3 illustrates a process for casting an article from a
molten mixture of multiple fluorides according to an
embodiment.
[0012] FIG. 4 illustrates a process for performing fluorine ion
heat treatment on an article or coating that includes a mixture of
oxides according to an embodiment.
[0013] FIG. 5 illustrates a process for performing fluorine ion
heat treatment on an article or coating that includes an oxide
according to an embodiment.
[0014] FIGS. 6A-6C depict sectional views of exemplary articles
according to various embodiments.
DETAILED DESCRIPTION OF EMBODIMENTS
[0015] Embodiments of the invention are directed to processes for
forming a fluoride glaze on a surface of a coating or an article
such as a chamber component for a processing chamber. In
embodiments multiple fluorides are mixed to form a eutectic system
having a melting temperature that is significantly lower than the
melting temperatures of the individual fluorides (e.g., up to
700.degree. C. lower in some instances), and then the mixture is
melted and reflowed at a surface of the article or the coating to
form the glaze. In other embodiments, an article or coating
includes a mixture of multiple oxides. A high temperature surface
treatment is then performed in a fluorine rich environment to
transform the multiple oxides into multiple fluorides. The multiple
fluorides then form the eutectic system, melt and form a glaze at a
surface of the article or the coating. Embodiments of the invention
are also directed to processes for forming an article having a
glass ceramic of multiple fluorides. The multiple fluorides may be
mixed and heated. The heated mixture may melt and form a eutectic
system. The molten mixture may then be poured into a mold and cast
to form the glass ceramic. Embodiments of the invention are also
directed to articles and coatings having fluoride glazes and
articles having fluoride glass ceramics.
[0016] Rare earth fluorides and metal fluorides generally have a
high resistance to fluorine based chemistries, and can be
characterized as a "fluorine based plasma resistant material."
Additionally, oxy-fluorides generally have a high resistance to
fluorine based chemistries. Rare earth fluorides, metal fluorides
and oxy-fluorides are all generally more stable than oxides when
exposed to fluorine chemistries. However, fluorides that are useful
in industry have high melting temperatures and high vapor pressures
near their melting temperatures. As a result, it can be very
difficult to form glazes from fluorides. Glazes can provide
improved performance for erosion resistance from plasma etch
chemistries due to their low porosity and low surface roughness in
comparison to standard ceramic coatings such as those deposited
using thermal spraying, plasma spraying, dip coating, and so
on.
[0017] The term "heat treating" is used herein to mean applying an
elevated temperature to a ceramic article, such as by a furnace.
"Plasma resistant material" refers to a material that is resistant
to erosion and corrosion due to exposure to plasma processing
conditions. The plasma processing conditions include a plasma
generated from 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. The resistance of the material to plasma is measured
through "etch rate" (ER), which may have units of Angstrom/min
(.ANG./min), throughout the duration of the coated components'
operation and exposure to plasma. Plasma resistance may also be
measured through an erosion rate having the units of
nanometer/radio frequency hour (nm/RFHr), where one RFHr represents
one hour of processing in plasma processing conditions.
Measurements may be taken after different processing times. For
example, measurements may be taken before processing, after 50
processing hours, after 150 processing hours, after 200 processing
hours, and so on. An erosion rate lower than about 100 nm/RFHr is
typical for a plasma resistant coating material. A single plasma
resistant material may have multiple different plasma resistance or
erosion rate values. For example, a plasma resistant material may
have a first plasma resistance or erosion rate associated with a
first type of plasma and a second plasma resistance or erosion rate
associated with a second type of plasma.
[0018] When the terms "about" and "approximately" are used herein,
these are intended to mean that the nominal value presented is
precise within .+-.10%. Some embodiments are described herein with
reference to chamber components and other articles installed in
plasma etchers for semiconductor manufacturing. However, it should
be understood that such plasma etchers may also be used to
manufacture micro-electro-mechanical systems (MEMS)) devices.
Additionally, the articles described herein may be other structures
that are exposed to plasma. Articles discussed herein may be
chamber components for processing chambers such as semiconductor
processing chambers. For example, the articles may be chamber
components for a plasma etcher, a plasma cleaner, a plasma
propulsion system, or other processing chambers. The processing
chambers may be used for processes in which a corrosive plasma
environment having plasma processing conditions is provided. For
example, the processing chamber may be a chamber for a plasma
etcher or plasma etch reactor, a plasma cleaner, and so forth.
Examples of chamber components include a substrate support
assembly, an electrostatic chuck (ESC), a ring (e.g., a process kit
ring or single ring), a chamber wall, a base, a gas distribution
plate, a showerhead, a nozzle, a lid, a liner, a liner kit, a
shield, a plasma screen, a flow equalizer, a cooling base, a
chamber viewport, a chamber lid, and so on.
[0019] Moreover, embodiments are described herein with reference to
ceramic articles that cause reduced particle contamination when
used in a process chamber for plasma rich processes. However, it
should be understood that the ceramic 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 , plasma enhanced chemical vapor
deposition (PECVD) chambers , plasma enhanced physical vapor
deposition (PEPVD) chambers , plasma enhanced atomic layer
deposition (PEALD) chambers, and so forth.
[0020] FIG. 1 illustrates an exemplary architecture of a
manufacturing system 100, in accordance with embodiments of the
present invention. The manufacturing system 100 may be a ceramics
manufacturing system. In one embodiment, the manufacturing system
100 includes processing equipment 101 (also referred to herein as
manufacturing machines) connected to an equipment automation layer
115. The processing equipment 101 may include a ceramic coater 104,
a grinder 103, a mixer 105 and/or a furnace 102. The manufacturing
system 100 may further include one or more computing device 120
connected to the equipment automation layer 115. In alternative
embodiments, the manufacturing system 100 may include more or fewer
components. For example, the manufacturing system 100 may include
manually operated (e.g., off-line) processing equipment 101 without
the equipment automation layer 115 or the computing device 120.
[0021] Grinders 103 are machines having an abrasive disk, wheel or
other grinding mechanism that grinds materials such as ceramics.
The grinders 103 may include a grinding system such as a ball mill
that reduces ceramics to powder. The grinders 103 may grind the
ceramics in multiple steps, where each step grinds the ceramics to
a finer powder having smaller diameter particles.
[0022] Mixers 105 are machines used to mix together ceramic
powders. One example of a mixer is a ball mill, which may also
function as a grinder in embodiments.
[0023] Ceramic coater 104 is a machine configured to apply a
ceramic coating to the surface of an article or object (e.g., to
the surface of a chamber component). In one embodiment, ceramic
coater 104 is a plasma sprayer that plasma sprays a ceramic coating
onto the ceramic substrate. In alternative embodiments, the ceramic
coater 104 may apply other thermal spraying techniques such as
detonation spraying, wire arc spraying, high velocity oxygen fuel
(HVOF) spraying, flame spraying, warm spraying and cold spraying
may be used. Additionally, ceramic coater 104 may perform other
coating processes such as aerosol deposition, physical vapor
deposition (PVD), doctor blade coating, dip coating, and chemical
vapor deposition (CVD) to form the ceramic coating.
[0024] Furnace 102 is a machine designed to heat articles such as
ceramic articles. Furnace 102 includes a thermally insulated
chamber, or oven, capable of applying a controlled temperature on
articles (e.g., ceramic articles) inserted therein. In one
embodiment, the chamber is hermitically sealed. Furnace 102 may
include a pump to pump air out of the chamber, and thus to create a
vacuum within the chamber. Furnace 102 may additionally or
alternatively include a gas inlet to pump gasses (e.g., inert
gasses such as Ar or N.sub.2 and/or reactive gases such as hydrogen
fluoride (HF)) into the chamber.
[0025] In one embodiment, the furnace 102 is a furnace (e.g., a
retort furnace) designed to perform fluoride ion cleaning (FIC).
FIC is a heat treatment that is performed in the presence of
anhydrous hydrogen fluoride (HF) gas to remove embedded oxides from
treated articles. A flow rate for the HF gas may depend on a size
of the furnace. In in embodiment, a flow rate for the HF gas of 1
liter per minute may be used for a 10 cubic foot furnace in one
embodiment. Other possible flow rates for the HF gas and for a 10
cubit coot furnace include 0.8-1.2 liters per minute. The flow rate
may scale with changes in chamber size. FIC may be performed in a
temperature range of 100 torr (122 mbar) to atmospheric pressure
and a temperature range of about 955 to 1040.degree. C. FIC may
also be performed at other temperatures as low as about 350.degree.
C. In one embodiment, FIC is performed at a temperature of at least
910.degree. . In FIC, HF gas contacts a surface of an article, and
is forced into voids and cracks in the surface. The HF gas reacts
with oxides to form fluorides. HF concentration, processing time,
pressure and temperature may be adjusted to achieve desired
results.
[0026] Furnace 102 may be a manual furnace having a temperature
controller that is manually set by a technician during processing
of ceramic articles. Furnace 102 may also be an off-line machine
that can be programmed with a process recipe 125. The process
recipe 125 may control ramp up rates, ramp down rates, process
times, temperatures, pressure, gas flows, and so on. Alternatively,
furnace 102 may be an on-line automated furnace that can receive
process recipes 125 from computing devices 120 such as personal
computers, server machines, etc. via an equipment automation layer
115. The equipment automation layer 115 may interconnect the
furnace 102 with computing devices 120, with other manufacturing
machines, with metrology tools and/or other devices.
[0027] The equipment automation layer 115 may interconnect some or
all of the manufacturing machines 101 with computing devices 120,
with other manufacturing machines, with metrology tools and/or
other devices. The equipment automation layer 115 may include a
network (e.g., a location area network (LAN)), routers, gateways,
servers, data stores, and so on. Manufacturing machines 101 may
connect to the equipment automation layer 115 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 115 enables
process data (e.g., data collected by manufacturing machines 101
during a process run) to be stored in a data store (not shown). In
an alternative embodiment, the computing device 120 connects
directly to one or more of the manufacturing machines 101.
[0028] In one embodiment, some or all manufacturing machines 101
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 101. 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.
[0029] 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).
[0030] In one embodiment, the manufacturing machines 101 are
programmed to execute recipes that will cause the manufacturing
machines to heat treat an article, coat a ceramic article, and so
on. In one embodiment, the manufacturing machines 101 are
programmed to execute process recipes 125 that perform operations
of a multi-step process for manufacturing an article or coating, as
described with reference to FIGS. 2-5. The computing device 120 may
store one or more process recipes 125 that can be downloaded to the
manufacturing machines 101 to cause the manufacturing machines 101
to manufacture articles in accordance with embodiments of the
present invention.
[0031] FIG. 2 is a flow chart showing a process 200 for
manufacturing a coating or article from a mixture of multiple
fluorides according to an embodiment. The operations of process 200
may be performed by various manufacturing machines, such as those
set forth in FIG. 1.
[0032] At block 205, a first fluoride is mixed with a second
fluoride. In one embodiment, the two fluorides are mixed by ball
milling. The first fluoride may be a metal fluoride or a rare earth
fluoride, and may be one of CaF.sub.2, MgF.sub.2, SrF.sub.2,
AlF.sub.3, ErF.sub.3, LaF.sub.3, NdF.sub.3, ScF.sub.3, CeF.sub.4,
TiF.sub.3, HfF.sub.4, ZrF.sub.4, SiF.sub.4, and YF.sub.3.
Additionally, the second fluoride may be a metal fluoride or a rare
earth fluoride, and may be one of CaF.sub.2, MgF.sub.2, SrF.sub.2,
AlF.sub.3, ErF.sub.3, LaF.sub.3, NdF.sub.3, ScF.sub.3, CeF.sub.4,
TiF.sub.3, HfF.sub.4, ZrF.sub.4, SiF.sub.4, and YF.sub.3. The first
fluoride and the second fluoride may have different melting
temperatures. A table listing various fluorides, their melting
temperatures and their densities is provided below.
TABLE-US-00001 TABLE 1 Fluoride melting temperatures and densities
Fluoride Melting Point (.degree. C.) Density (g/cm.sup.3) CaF.sub.2
1360 3.18 MgF.sub.2 1263 3.15 SrF.sub.2 1450 4.24 AlF.sub.3 1257
3.19 ErF.sub.3 1350 7.8 LaF.sub.3 1490 4.01 NdF.sub.3 1410 6.65
ScF.sub.3 1552 2.53 CeF.sub.4 1418 4.77 TiF.sub.3 1200 3.4
HfF.sub.4 1000 7.1 ZrF.sub.4 910 4.43 YF.sub.3 1487 4.01
[0033] The molar percentage (mole %) of the first fluoride and the
molar percentage (mole %) of the second fluoride that are mixed may
be based on the ratio of the first fluoride to the second fluoride
that can achieve a eutectic system of the two fluorides. The ratio
of two components that can achieve a eutectic system is referred to
as a eutectic percentage ratio. For most combinations the eutectic
system can be achieved at about 50 mole % of the first fluoride and
50 mole % of the second fluoride (e.g., the eutectic percentage
ratio is about 45-55% of both fluorides). However, some
combinations of fluorides use a combination of about 20-40 mole %
of the first fluoride and 60-80 mole % of the second fluoride to
form a eutectic system. For example, a combination of about 47-52
mole % ErF.sub.3 and 48-53 mole % HfF.sub.4 may achieve a eutectic
system. A combination of about 45-55 mole % NdF.sub.3 and 45-55
mole % HfF.sub.4 may achieve a eutectic system. A combination of
about 48-52 mole % YF.sub.3 and 48-52 mole % HfF.sub.4 may achieve
a eutectic system. A combination of about 45-55 mole % LaF.sub.4
and 45-55 mole % HfF.sub.4 may achieve a eutectic system. A
combination of about 23-37 mole % ZrF.sub.4 and 63-77 mole %
LaF.sub.4 may achieve a eutectic system.
[0034] As shown in table 1, ZrF.sub.4 has a melting temperature of
910.degree. C., which is lower than the melting temperatures of any
of the other rare earth fluorides and metal fluorides listed.
Zirconium based fluorides and zirconium based oxides have
beneficial property with regards to plasma resistance.
Additionally, due to the relatively low melting temperature of
ZrF.sub.4, eutectic systems formed from ZrF.sub.4 and another
fluoride have melting temperatures that are favorably low (e.g., as
low as around 700.degree. C. in some embodiments). Accordingly, in
one embodiment the mixture includes ZrF.sub.4 and another fluoride.
In one embodiment, a third fluoride and/or a fourth fluoride are
also mixed together with the first fluoride and the second
fluoride.
[0035] The coefficient of thermal expansion (CTE) of fluorides are
generally higher than the CTE of oxide counterparts. For example,
YF.sub.3 has a CTE of 14 ppm/K and Y.sub.2O.sub.3 has a CTE of 6
ppm/K. A fluoride rich glaze over an oxide may result in stress
and/or cracking in the glaze due to the differences in CTE.
ScF.sub.3 is a rare earth fluoride with a melting temperature of
1552.degree. C. and a negative CTE of -7 ppm/K at room temperature.
ScF.sub.3 may be used as the first fluoride or the second fluoride
in embodiments to reduce a CTE of a coating formed from the
fluoride mixture and minimize a mismatch between a glaze formed
from the fluoride mixture and an underlying oxide. In one
embodiment, a mixture of at least three fluorides that includes
ZrF.sub.4, ScF.sub.3 and at least one other fluoride (e.g.,
TiF.sub.4 or YF.sub.3) is used. The molar percentages of these the
at least three fluorides may be selected to correspond to the
eutectic percentage ratio for the selected fluorides.
[0036] At block 210, the mixture of the first fluoride and the
second fluoride (an in some instances one or more additional
fluorides) is heated to a first temperature to melt the first
fluoride and/or the second fluoride. In one embodiment, the mixture
is heated to a temperature that is above the melting temperature of
the first fluoride but below the melting temperature of the second
fluoride, where the first fluoride has a lower melting temperature
than the second fluoride. For example, if the mixture includes
ZrF.sub.4 and YF.sub.3, the mixture may be heated to a temperature
that is between 910.degree. C. and 1000.degree. C. The first
fluoride melts, and the molten first fluoride causes a portion of
the second fluoride (and/or other fluorides) to dissolve and also
become molten.
[0037] The molten second fluoride (and/or other fluorides) mixes
with the molten first fluoride and slightly lowers the melting
temperature of the remaining second fluoride (and/or other
fluorides). An additional amount of the second fluoride (and/or
other fluorides) dissolves and becomes molten, which then further
mixes with the molten first fluoride (and/or other fluorides). The
addition of more molten second fluoride (and/or other molten
fluorides) to the molten mixture further reduces the melting
temperature, which enables still more of the second fluoride
(and/or other fluorides) to dissolve and become molten. This
process may continue until all of the second fluoride (and/or other
fluorides) becomes molten even though the mixture has not been
heated to the melting temperature of the second fluoride (and/or
other fluorides). In an alternative embodiment, the mixture may be
heated to a temperature that is above the melting point of the
first fluoride and the melting point of the second fluoride (and/or
other fluorides).
[0038] At block 215, the molten mixture of the first fluoride and
the second fluoride (and possibly other fluorides) is cooled to
form a material comprising a eutectic system. The eutectic system
is a joint super-lattice of the first fluoride and the second
fluoride. Each fluoride in the eutectic system has its own distinct
bulk lattice arrangement. The eutectic system is formed at a
particular molar ratio (or narrow range of molar ratios) between
the first fluoride and the second. fluoride. At the particular
molar ratio range, the eutectic system gains a new melting
temperature that is lower than the melting temperature of the first
fluoride and the melting temperature of the second fluoride (and
the melting temperatures of any additional constituent fluorides).
The new lower melting temperature is called the eutectic
temperature. At the eutectic temperature the super-lattice releases
at once all its coo components into a liquid mixture during
heating. Conversely, as the mixture of molten fluorides that has
the eutectic percentage ratio is cooled to the eutectic
temperature, the two (or more) fluorides solidify together into a
homogeneous solid mix of the two (or more) fluorides that is
arranged as a jointsuper-lattice of the two more) fluorides. The
eutectic temperature is the lowest possible melting temperature
over all of the mixing ratios for the involved component species.
As an example, a mixture of 23-37 mole % of ZrF.sub.4 and 63-77
mole % LaF.sub.4 has a eutectic temperature of approximately
770.degree. C.
[0039] As indicated above, in some embodiments, a third and/or
fourth fluoride may also be mixed with the first fluoride and the
second fluoride. A ratio of the first fluoride, the second
fluoride, the third fluoride and/or fourth fluoride may be selected
to reach the eutectic percentage ratio of the mixture. In such an
embodiment, all three or four fluorides would melt at block 210,
and the three or four fluorides would similarly form a ceramic that
has a composition that is a eutectic system on cooling. For
example, a mixture of approximately 50 mole % YF.sub.3,
approximately 15 mole % ZrF.sub.4 and approximately 35 mole %
ScF.sub.3 may have a melting temperature of around 800.degree. C.
(which is at or near the eutectic temperature for the combination
of ZrF.sub.4, ScF.sub.3 and YF.sub.3). The mixture may also have a
CTE of about 7 ppm/K, which is similar to the CTE of
Al.sub.2O.sub.3 and Y.sub.2O.sub.3.
[0040] At block 220, the ceramic having the eutectic system is
ground into powder. The powder may have an average diameter of
about 0.25 microns to about 4 microns in some embodiments. The size
off the powder may be dependent on a surface that will be coated
using the powder. If the powder will be used to form a slurry that
will coat features such as holes, then a smaller particle size may
be used.
[0041] At block 225, the powder is mixed with a solvent to form a
slurry. The slurry may be formed by suspending the powder in a
suspending medium (e.g., a solvent), which may include a binder.
The solvent used to form the slurry may be an organic solvent or a
nonorganic solvent, and may or may not be a polar solvent. Examples
of solvents that may be used include isopropyl alcohol, water,
ethanol, methanol, and so on. Examples of binders that may be added
to the solvent include polyvinyl alcohol (PVA) and/or polymeric
cellulose ether.
[0042] At block 230, the slurry is used to form a coating or an
article. In one embodiment, a coating is formed from the slurry by
performing a deposition technique such as thermal spray coating,
plasma spray coating, doctor blade coating, dip coating, spin
coating, screen printing, or other coating techniques that apply
slurries. A thickness of the coating may be dependent on the
deposition method used to form the coating. Additionally, the
thickness of the coating may be adjusted by adjusting slurry
viscosity, pH, and/or the binder. In embodiments the coating has a
thickness of between 1 micron and 500 microns. In some embodiments,
the coating has a thickness of about 10 microns to about 200
microns. In some embodiments, the coating has a thickness of about
20 microns to about 60 microns. The coating may be deposited on an
article such as a chamber component for a processing chamber. Using
techniques such as dip coating, the coating can be formed over
three dimensional (3D) structures such as the walls of a gas line
or the holes in a showerhead. In one embodiment, the coating is
formed in a vacuum or an inert atmosphere (e.g., in an Ar or
N.sub.2 atmosphere).
[0043] In one embodiment, an article is formed from the slurry. The
slurry may be poured into a mold and cast into a shape governed by
the shape of the mold. The solvent may evaporate to leave behind an
article that is a ceramic solid having the shape set by the mold.
The article may then be removed from the mold. In one embodiment,
the article is formed in a vacuum or an inert atmosphere (e.g., in
an Ar or N.sub.2 atmosphere).
[0044] At block 235, the article and/or coating are heated to a
second temperature to cause the coating or article to become molten
and reflow. At block 240, the article is cooled, and during the
cooling the article transforms into a glaze or a glass ceramic
(also referred to as a glass ceramic). Since the article or coating
is formed from a eutectic system of at least two fluorides, the
melting temperature for the article or the coating is the eutectic
temperature, which can be significantly lower than the melting
temperature of the individual fluorides. Accordingly, the second
temperature is lower than the first temperature that was used to
initially create the eutectic system.
[0045] In the instance that an article was formed from the slurry,
a surface of the article may form a glaze or glass ceramic (e.g., a
glass ceramic). The glaze that is formed on the surface of the
article may have a thickness of up to about 100 microns in
embodiments. In the instance that a coating was formed from the
slurry and deposited on an article, either a portion of the coating
or all of the coating may melt, reflow and transform into a glaze
or glass ceramic. The glaze or glass ceramic may have a porosity of
below 1%. In some instances, the porosity is 0% or close to 0%. The
glaze or glass ceramic may also have a low average surface
roughness (Ra), which may have a value as low as 5 micro-inches in
embodiments.
[0046] A glaze is a specialized form of glass and can be described
as an amorphous solid. A glass ceramic or glass network is a
specialized form of ceramics, which is formed first as a glass and
then made to crystallize partly through a designed heat treatment
which involves controlled cooling. Unlike traditional sintered
ceramics, glass ceramics do not have pores between crystal grains.
The spacing between grains is filled with the glass. Glass ceramics
share many properties with both glass and traditional crystalline
ceramics. After adjusting the composition of glass ceramics by
processing, the final material may exhibit a number of properties
that the traditional ceramics do not have. When the melted coating
or surface of the article is cooled rapidly, typically a glaze is
produced. When the coating or surface of the article is cooled
slowly, a glass-ceramic may be produced.
[0047] FIG. 3 illustrates a process 300 for casting an article from
a molten mixture of multiple fluorides according to an embodiment.
The operations of process 300 may be performed by various
manufacturing machines, such as those set forth in FIG. 1.
[0048] At block 305, a first fluoride is mixed with a second
fluoride. In one embodiment, the two fluorides are mixed by ball
milling. The first fluoride may be a metal fluoride or a rare earth
fluoride, and may be one of CaF.sub.2, MgF.sub.2, SrF.sub.2,
AlF.sub.3, ErF.sub.3, LaF.sub.3, NdF.sub.3, ScF.sub.3, CeF.sub.4,
TiF.sub.3, HfF.sub.4, ZrF.sub.4, and YF.sub.3. Additionally, the
second fluoride may be a metal fluoride or a rare earth fluoride,
and may be one of CaF.sub.2, MgF.sub.2, SrF.sub.2, AlF.sub.3,
ErF.sub.3, LaF.sub.3, NdF.sub.3, ScF.sub.3, CeF.sub.4, TiF.sub.3,
HfF.sub.4, ZrF.sub.4, and YF.sub.3. In one embodiment the mixture
includes ZrF.sub.4 and another fluoride. In one embodiment, a third
fluoride and/or a fourth fluoride are also mixed together with the
first fluoride and the second fluoride.
[0049] The molar percentage (mole %) of the first fluoride and the
molar percentage (mole %) of second fluoride that are mixed may be
based on the ratio of the first fluoride to the second fluoride
that can achieve a eutectic system of the two fluorides.
Accordingly, the ratio of the first fluoride to the second fluoride
that is used corresponds to the eutectic percentage ratio for those
fluorides. If more than two fluorides are used, then the ratios of
the three or four fluorides are in accordance with the eutectic
percentage ratio for that combination of three or four
fluorides.
[0050] At block 310, the mixture of the first fluoride and the
second fluoride (and optionally the third fluoride and/or fourth
fluoride) is heated to a first temperature to melt the first
fluoride and/or the second fluoride (and optionally the third
and/or fourth fluoride). In one embodiment, the mixture is heated
to a temperature that is above the melting temperature of the first
fluoride but below the melting temperature of the second fluoride
(and/or additional fluorides), where the first fluoride has a lower
melting temperature than the second fluoride (and/or additional
fluorides). For example, if the mixture includes ZrF.sub.4 and
YF.sub.3, the mixture may be heated to a temperature that is
between 910.degree. C. and 1000.degree. C. The first fluoride
melts, and the molten first fluoride causes a portion of the second
fluoride to dissolve and also become molten.
[0051] The molten second fluoride (and/or additional fluorides)
mixes with the molten first fluoride and slightly lowers the
melting temperature of the remaining second fluoride (and/or
additional fluorides). An additional amount of the second fluoride
dissolves and becomes molten, which then further mixes with the
molten first fluoride. The addition of more molten second fluoride
(and/or additional fluorides) to the molten mixture further reduces
the melting temperature, which enables still more of the second
fluoride (and/or additional fluorides) to dissolve and become
molten. This process may continue until all of the second fluoride
(and/or additional fluorides) becomes molten even though the
mixture has not been heated to the melting temperature of the
second fluoride (and/or additional fluorides). In an alternative
embodiment, the mixture may be heated to a temperature that is
above the melting point of the first fluoride and the melting point
of the second fluoride and/or additional fluorides.
[0052] At block 315, the molten mixture of the first fluoride and
the second fluoride is poured into a mold and cast in the mold. In
one embodiment, the casting is performed in a vacuum or an inert
atmosphere (e.g., in an Ar or N.sub.2 atmosphere). At block 320,
the melted or molten mixture is cooled to form an article composed
of a material comprising a eutectic system. As the mixture of
molten fluorides that has the eutectic percentage ratio is cooled
to the eutectic temperature, the two (or more) fluorides solidify
together into a homogeneous solid mix of the two (or more)
fluorides that is arranged as a jointsuper-lattice of the two more)
fluorides. The cooled article may be a glass ceramic having a
network of the two fluorides. At block 325, the article is removed
from the mold.
[0053] In an alternative embodiment, the molten mixture may be
cooled to form a ceramic without casting the molten mixture a mold.
The ceramic may then be ground into powder. At a later time, the
powder may be heated to the eutectic temperature to melt the
powder, and the melted powder may be cast into the mold to form a
shape. Alternatively, the ceramic may not be ground into a powder
prior to melting it to perform the casting. In either case, the
ceramic is a eutectic system of the two or more fluorides, and will
melt at the eutectic temperature.
[0054] FIG. 4 illustrates a process 400 for performing fluorine ion
heat treatment on an article or coating that includes a mixture of
oxides according to an embodiment. The operations of process 400
may be performed by various manufacturing machines, such as those
set forth in FIG. 1. In one embodiment, FIC is performed on the
article or coating.
[0055] At block 405, an article may be formed from an initial
mixture that includes a first oxide and a second oxide. The mixture
may also include more than two oxides. The article may be a bulk
sintered ceramic article, and may be a chamber component.
Alternatively, at block 405 a coating of an initial mixture that
includes a first oxide and a second oxide (and possible one or more
additional oxides) is formed on the surface of an article. The
article may be a chamber component.
[0056] The first oxide and the second oxide may each be one of
Y.sub.2O.sub.3, Nd.sub.2O.sub.3, La.sub.2O.sub.3, Er.sub.2O.sub.3,
Sc.sub.2O.sub.3, TiO.sub.2, ZrO.sub.2, HfO.sub.2, Al.sub.2O.sub.3
and SiO.sub.2. The initial mixture of the two or more oxides may
have various compositions. For example, the initial mixture may be
a mixture of Y.sub.2O.sub.3 and Al.sub.2O.sub.3 in the form of
Y.sub.3Al.sub.5O.sub.12 (YAG) or Y.sub.4Al.sub.2O.sub.9 (YAM). In
another example, the initial mixture may be a mixture of
Y.sub.2O.sub.3 and ZrO.sub.2 in the form of Y.sub.2O.sub.3
stabilized ZrO.sub.2 (YSZ). In another example, the initial mixture
may Er.sub.3Al.sub.5O.sub.12 (EAG), Gd.sub.3Al.sub.5O.sub.12 (GAG),
or a ceramic compound comprising Y.sub.4A1.sub.20.sub.9 and a
solid-solution of Y.sub.2O.sub.3--ZrO.sub.2. The ratio of the first
oxide to the second oxide (and/or additional oxides) may be
configured such that during later heat treatment in the presence of
HF gas the oxides will convert to a mixture of two (or more)
fluorides that has the eutectic percentage ratio.
[0057] At block 410, the article or coating is heated to a
treatment temperature that is above a melting temperature of at
least one of the fluorides that will be formed from the two (or
more) oxides. For example, ZrO.sub.2 may be converted into
ZrF.sub.4, which has a melting temperature of 910.degree. C. If the
article or coating includes ZrO.sub.2, then the article or coating
may be heated to a temperature that is above 910.degree. C. In one
embodiment, the article is heated to a temperature of about 910 to
1040.degree. C. In one embodiment, the article is heated to a
temperature of about 955 to 1040.degree. C.
[0058] At block 415, the article or coating is exposed to HF gas
(e.g., anhydrous hydrogen fluoride gas) at the treatment
temperature of over 910.degree. C. The heat treatment in the
presence of the HF gas causes a chemical reaction at the surface of
the article or coating that converts the oxides into fluorides.
Some example reactions are shown below:
6HF+Al.sub.2O.sub.3.fwdarw.2AlF.sub.3+3H.sub.2O
6HF+Y.sub.2O.sub.3.fwdarw.2YF.sub.3+3H.sub.2O
4HF+ZrO.sub.2.fwdarw.ZrF.sub.4+2H.sub.2O
[0059] The water that results from the reaction evaporates at the
treatment temperature, leaving behind the fluoride. Accordingly, at
block 420 a chemical reaction is performed that replaces the oxygen
molecules in the first oxide and the second oxide (and any
additional oxides) with fluorine molecules at a surface of the
article or coating. The reaction depth is a function of time and
temperature. The reaction may penetrate into the surface of the
article or coating to a depth of from about 0.5 microns to a depth
of up to about 100 microns in some embodiments. At block 425, the
initial mixture of the first oxide and the second oxide (and any
additional oxides) is transformed into a final mixture of a first
fluoride and a second fluoride (and any additional fluorides).
[0060] If the ratio of the first oxide and the second oxide (and/or
any additional oxides) was chosen correctly, then the final mixture
of the first fluoride and the second fluoride (and/or any
additional fluorides) will have the eutectic percentage ratio. As
set forth above, the treatment temperature is above the lowest
melting temperature of the two (or more) fluorides. For example, if
the final mixture includes ZrF.sub.4 and YF.sub.3, the mixture may
be heated to a temperature that is between 910.degree. C. and
1000.degree. C. The first fluoride melts, and the molten first
fluoride causes a portion of the second fluoride to dissolve and
also become molten.
[0061] The molten second fluoride mixes with the molten first
fluoride and slightly lowers the melting temperature of the
remaining second fluoride. An additional amount of the second
fluoride dissolves and becomes molten, which then further mixes
with the molten first fluoride. The addition of more molten second
fluoride to the molten mixture further reduces the melting
temperature, which enables still more of the second fluoride to
dissolve and become molten. This process may continue until all of
the second fluoride becomes molten even though the mixture has not
been heated to the melting temperature of the second fluoride. In
an alternative embodiment, the mixture may be heated to a
temperature that is above the melting point of the first fluoride
and the melting point of the second fluoride.
[0062] A similar process may occur if there are more than two
fluorides. The exposure to the HF gas at the elevated temperature
additionally may cause any trace metals such as transition metals
or aluminum to vaporize and be removed from the surface of the
article or coating. Accordingly, the heat treatment in the presence
of HF gas (e.g., FIC process) may be used both to remove impurities
and form a fluorides glaze. In one embodiment, the article or
coating is a ceramic compound of Y.sub.4Al.sub.2O.sub.9 and a
solid-solution of Y.sub.2O.sub.3--ZrO.sub.2. The exposure to the HF
gas at the elevated temperature of at least 910.degree. C. may
cause the Al to form AlF.sub.3, which boils off of the coating or
article. The exposure to the HF gas at the elevated temperature
further causes formation of YF.sub.3 and ZrF.sub.4, which may form
a eutectic system and a glaze.
[0063] At block 430, the article or coating that includes the
molten mixture of the first fluoride and the second fluoride (and
any additional fluoride) is cooled to form a material comprising a
eutectic system. The article or coating is cooled in a manner that
causes the material to form a glaze of the eutectic system. As the
mixture of molten fluorides that has the eutectic percentage ratio
is cooled to the eutectic temperature, the two (or more) fluorides
solidify together into a homogeneous solid mix of the two (or more)
fluorides that is arranged as a joint super-lattice of the two (or
more) fluorides. The glaze may have a thickness of about 1 micron
to about 100 microns. In one embodiment, the entire coating is
converted to a glaze, and the glaze is the thickness of the
coating. In one embodiment, the glaze has a thickness that is 50%
to 100% of the thickness of a coating that the glaze is formed
from. Accordingly, half to all of the coating may be transformed
into a glaze in embodiments.
[0064] FIG. 5 illustrates a process 500 for performing fluorine ion
heat treatment on an article or coating that includes an oxide
according to an embodiment. The operations of process 500 may be
performed by various manufacturing machines, such as those set
forth in FIG. 1.
[0065] At block 505, an article may be formed from an oxide. In one
embodiment, the oxide is Al.sub.2O.sub.3. Alternatively, the oxide
may be Y.sub.2O.sub.3, ZrO.sub.2, Nd.sub.2O.sub.3, La.sub.2O.sub.3,
Er.sub.2O.sub.3, Sc.sub.2O.sub.3, TiO.sub.2, HfO.sub.2, SiO.sub.2
or another oxide. The article may be a bulk sintered ceramic
article, and may be a chamber component. Alternatively, at block
505 a coating that is an oxide is formed on the surface of an
article. The article may be a chamber component.
[0066] At block 510, the article is heated to a treatment
temperature that is high enough to facilitate a chemical reaction
that causes at least a portion of the oxide to become a fluoride,
but below the melting temperature of materials to be treated. In
one embodiment, the article is heated to a temperature of
approximately 350.degree. C. In another example, the article is
heated to a temperature in a range from about 350.degree. C. to
about 1000.degree. C. In another example, the article is heated to
a temperature of about 1000.degree. C. For example, a temperature
of 350.degree. C. may be used if the article or coating is
Al.sub.2O.sub.3.
[0067] At block 515, the article or coating is exposed to HF gas
(e.g., anhydrous hydrogen fluoride gas) at the treatment
temperature of around 350.degree. C. The heat treatment in the
presence of the HF gas causes a chemical reaction at the surface of
the article or coating that converts at least a portion of the
oxide into a fluoride. Accordingly, at block 520 a chemical
reaction is performed that replaces the oxygen molecules in the
oxide with fluorine molecules at a surface of the article or
coating. The reaction may penetrate into the surface of the article
or coating to a depth of from about 0.5 microns to a depth of up to
about 40 microns in embodiments. If all of the oxygen is replaced
with fluorine at the surface, than the surface of the article or
coating becomes a fluoride. For example, Al.sub.2O.sub.3 may become
AlF.sub.4. If less than all of the oxygen is converted into
fluorine, then the surface becomes a metal oxy-fluoride or rare
earth oxy-fluoride. Both the fluoride and the oxy-fluoride may be
resistant to erosion from fluorine chemistries. At block 525, the
article or coating is then cooled. Process 500 may be performed in
embodiments as a replacement to anodization.
[0068] FIGS. 6A-6C depict sectional views of exemplary articles
according to various embodiments. FIG. 6A illustrates an article
600 having a body 605 and a glaze 608 formed at a surface of the
body 605. The body 605 may comprise various chamber components
including but not limited to substrate support assembly, an
electrostatic chuck (ESC), a ring (e.g., a process kit ring or
single ring), a chamber wall, a base, a gas distribution plate, a
showerhead, a nozzle, a lid, a liner, a liner kit, a shield, a
plasma screen, a flow equalizer, a cooling base, a chamber
viewport, a chamber lid, and so on. The body may be a bulk sintered
ceramic that includes a combination of two or more fluorides that
have the eutectic percentage ratio or approximately the eutectic
percentage ratio. Alternatively, the body may be a bulk sintered
ceramic that includes a single oxide or a combination of multiple
oxides having a ratio that, when converted to fluorides, is at or
near the eutectic percentage ratio for the mixture of fluorides.
The glaze 608 may have been formed by any of the techniques
described herein. The glaze may have a thickness of up to 100
microns in some embodiments.
[0069] FIG. 6B illustrates an article 610 having a body 615, a
coating 613 on a surface of the body 615, and a glaze 618 on a
surface of the coating 613. The article 610 may be a metal (such as
aluminum, stainless steel), a ceramic, a metal-ceramic composite, a
polymer, a polymer ceramic composite, or other suitable materials,
and may further comprise materials such as AlN, Si, SiC,
Al.sub.2O.sub.3, SiO.sub.2, and so on. The coating 613 may be a
plasma resistant coating that was coated on the body 605 through
various techniques depending on the chosen application and coating
properties. Some of the coating techniques may be plasma spraying
techniques, thermal spraying techniques such as detonation
spraying, wire arc spraying, high velocity fuel (HVOF) spraying,
flame spraying, warm spraying and cold spraying, aerosol
deposition, e-beam evaporation, electroplating, ion assisted
deposition (IAD), physical vapor deposition (PVD), chemical vapor
deposition (CVD), and plasma assisted deposition.
[0070] In one embodiment, the coating 613 is composed of a ceramic
mixture including multiple different fluorides. The ratios of the
multiple different fluorides in the coating may be at or near the
eutectic percentage ratio for the mixture of fluorides. In such an
embodiment, the coating may have been formed by any technique for
coating a surface with a slurry, such as dip coating, spray
coating, doctor blade coating, and so on. The coating may have a
thickness of about 1 micron to about 100 microns. The glaze may
also have a thickness of about 1 micron to about 100 microns. In
one embodiment, the glaze has a thickness that is 50% to 100% of
the thickness of the coating.
[0071] In one embodiment, the coating 613 is an oxide coating. The
oxide coating may include a single metal or rare earth species, or
may include multiple metal and/or rare earth species. If the
coating 613 includes multiple metal and/or rare earth species, then
the ratio of these species is selected such that when converted to
a mixture of fluorides, those fluorides are at the eutectic
percentage ratio. The glaze 618 may have been formed from the
coating 613 using any of the techniques described herein.
[0072] FIG. 6C illustrates an article 660 having a body 665 that is
a glass ceramic. The article 600 may include multiple fluoride
species. The percentages of the different fluoride species may be
at the eutectic ratio percentage for those species.
[0073] 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 invention. It will be apparent to one
skilled in the art, however, that at least some embodiments of the
present invention 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 invention.
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
invention.
[0074] 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." When the term
"about" or "approximately" is used herein, this is intended to mean
that the nominal value presented is precise within .+-.10%.
[0075] 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.
[0076] 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
invention should be determined with reference to the appended
claims, along with the full scope of equivalents to which such
claims are entitled.
* * * * *