U.S. patent application number 15/353429 was filed with the patent office on 2017-05-18 for corrosion-resistant components and methods of making.
The applicant listed for this patent is CoorsTek, Inc.. Invention is credited to Ramesh Divakar, Alan Filer, Matthew Simpson.
Application Number | 20170140902 15/353429 |
Document ID | / |
Family ID | 57544516 |
Filed Date | 2017-05-18 |
United States Patent
Application |
20170140902 |
Kind Code |
A1 |
Simpson; Matthew ; et
al. |
May 18, 2017 |
CORROSION-RESISTANT COMPONENTS AND METHODS OF MAKING
Abstract
A corrosion-resistant component configured for use with a
semiconductor processing reactor, the corrosion-resistant component
comprising: a) a ceramic insulating substrate; and, b) a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer
having a composition comprising at least 15% by weight of a rare
earth compound based on total weight of the corrosion-resistant
non-porous layer; and, the corrosion-resistant non-porous layer
characterized by a microstructure substantially devoid of
microcracks and fissures, and having an average grain size of at
least about 100 nm and at most about 100 .mu.m. Assemblies
including corrosion-resistant components and methods of making are
also disclosed.
Inventors: |
Simpson; Matthew;
(Evergreen, CO) ; Divakar; Ramesh; (Arvada,
CO) ; Filer; Alan; (Longmont, CO) |
|
Applicant: |
Name |
City |
State |
Country |
Type |
CoorsTek, Inc. |
Golden |
CO |
US |
|
|
Family ID: |
57544516 |
Appl. No.: |
15/353429 |
Filed: |
November 16, 2016 |
Related U.S. Patent Documents
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Application
Number |
Filing Date |
Patent Number |
|
|
62255769 |
Nov 16, 2015 |
|
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Current U.S.
Class: |
1/1 |
Current CPC
Class: |
C04B 35/581 20130101;
C04B 2235/96 20130101; C04B 2237/36 20130101; C04B 2235/9669
20130101; C04B 2237/343 20130101; C23C 16/46 20130101; C04B
2235/3427 20130101; C04B 2235/9607 20130101; C04B 35/62655
20130101; C04B 2237/064 20130101; C04B 2237/403 20130101; H01J
37/32477 20130101; C04B 2237/062 20130101; H01J 2237/334 20130101;
H01J 2237/166 20130101; C04B 2235/786 20130101; C04B 2237/122
20130101; C04B 2237/341 20130101; C04B 2235/3217 20130101; C04B
2235/5454 20130101; C04B 2235/788 20130101; H01L 21/67069 20130101;
H01L 21/6719 20130101; C23C 14/564 20130101; C04B 35/6455 20130101;
C04B 2235/658 20130101; C04B 2235/72 20130101; C04B 2235/721
20130101; H01J 37/3244 20130101; C04B 35/505 20130101; C04B
2235/3225 20130101; C04B 2235/3244 20130101; C04B 2235/3891
20130101; C04B 2235/5445 20130101; C04B 2237/368 20130101; C04B
35/50 20130101; C04B 2235/3847 20130101; C04B 2237/708 20130101;
H01J 2237/3341 20130101; B32B 18/00 20130101; C04B 2235/442
20130101; C04B 2235/6562 20130101; C04B 2235/80 20130101; C04B
2237/366 20130101; C04B 2235/3865 20130101; C04B 2235/604 20130101;
C23C 16/45565 20130101; C04B 2235/6567 20130101; C04B 2237/34
20130101; H01J 37/32522 20130101; C04B 2235/9661 20130101; C04B
2235/9692 20130101; C04B 2235/3895 20130101; C04B 2235/445
20130101; C04B 2235/3229 20130101; H01J 37/32119 20130101; C04B
2235/3224 20130101; C04B 2235/77 20130101; C04B 2237/68 20130101;
C23C 16/4404 20130101; H01J 37/32862 20130101; C04B 35/62675
20130101; C04B 2237/567 20130101; C04B 2235/785 20130101; C04B
35/645 20130101; C04B 2237/704 20130101; C04B 35/10 20130101 |
International
Class: |
H01J 37/32 20060101
H01J037/32; C23C 16/46 20060101 C23C016/46; C04B 35/50 20060101
C04B035/50; C04B 35/10 20060101 C04B035/10; C04B 35/505 20060101
C04B035/505; C04B 35/581 20060101 C04B035/581; C23C 16/455 20060101
C23C016/455; H01L 21/67 20060101 H01L021/67 |
Claims
1. A corrosion-resistant component configured for use with a
semiconductor processing reactor, the corrosion-resistant component
comprising: a) a ceramic insulating substrate; and, b) a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer
having a composition comprising at least 15% by weight of a rare
earth compound based on total weight of the corrosion-resistant
non-porous layer; and, the corrosion-resistant non-porous layer
characterized by a microstructure substantially devoid of
microcracks and fissures, and having an average grain size of at
least about 100 nm and at most about 100 .mu.m.
2. The corrosion-resistant component of claim 1, wherein the
ceramic insulating substrate is selected from the group consisting
of aluminum oxide, aluminum nitride, silicon nitride,
silicate-based materials and mixtures of two or more thereof.
3. The corrosion-resistant component of claim 2, wherein the rare
earth compound is selected from the group consisting of yttrium
oxide (Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides,
yttrium oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof.
4. The corrosion-resistant component of claim 3, wherein the
corrosion-resistant non-porous layer is adhered to the ceramic
insulating substrate, and the corrosion-resistant non-porous layer
has: a. a porosity of at most 1%; b. an adhesion strength of at
least 20 MPa; and, c. a thickness of at least 50 .mu.m.
5. The corrosion-resistant component of claim 4, wherein the
corrosion-resistant non-porous layer has: a. a porosity of at most
0.5%; b. an adhesion strength of at least 30 MPa; c. a thickness of
at least 100 .mu.m; and, d. an average grain size of at least about
300 nm and at most about 30 .mu.m.
6. The corrosion-resistant component of claim 1, wherein the
ceramic insulating substrate is aluminum oxide and the rare earth
compound is a trivalent rare earth oxide.
7. The corrosion-resistant component of claim 1, wherein the
ceramic insulating substrate is aluminum nitride and the
corrosion-resistant non-porous layer is a rare earth silicate.
8. The corrosion-resistant component of claim 1, wherein the
corrosion-resistant component is a lid configured for releasable
engagement with a plasma etch reactor and has a loss tangent of
less than 1.times.10.sup.-4.
9. The corrosion-resistant component of claim 1, further comprising
at least one interposing layer embedded in the ceramic insulating
substrate, or layered between the ceramic insulating substrate and
the corrosion-resistant non-porous layer.
10. The corrosion-resistant component of claim 9, wherein the at
least one interposing layer is selected from the group consisting
of rare earth oxides, rare earth silicates, rare earth aluminates,
and mixtures of two or more thereof.
11. The corrosion-resistant component of claim 10, wherein the at
least one interposing layer is ytterbium oxide
(Yb.sub.2O.sub.3).
12. The corrosion-resistant component of claim 10, wherein the at
least one interposing layer comprises conducting materials.
13. The corrosion-resistant component of claim 12, wherein the at
least one interposing layer further comprises insulating
materials.
14. The corrosion-resistant component of claim 11, wherein the at
least one interposing layer is adhered to both the
corrosion-resistant non-porous layer and to the ceramic insulating
substrate, and the corrosion-resistant non-porous layer has: a. a
porosity of at most 1%; b. an adhesion strength of at least 20 MPa;
and, c. a thickness of at least 50 .mu.m.
15. A green laminate configured for use with a semiconductor
processing reactor, the green laminate comprising: a first layer of
green sinterable material selected from the group consisting of
aluminum oxide, aluminum nitride, silicon nitride, silicate-based
materials, and mixtures of two or more thereof; a second layer of
green sinterable material selected from the group consisting of
yttrium oxide (Y.sub.2O.sub.3), yttrium silicates, yttrium
fluorides, yttrium oxyfluorides, yttrium aluminates, nitrides,
complex nitride compounds, and combinations of two or more thereof;
and, wherein upon heat treatment of the green laminate, the second
layer has a porosity of at most 1% and an average grain size of at
least about 100 nm and at most about 100 .mu.m.
16. The green laminate of claim 15, wherein upon heat treatment of
the green laminate, the second layer has a porosity of at most 0.5%
and an average grain size of at least about 300 nm and at most
about 30 .mu.m.
17. The green laminate of claim 16, further comprising at least one
interposing layer between the first and second layers, wherein the
at least one interposing layer comprises green sinterable material
selected from the group consisting of rare earth oxides, rare earth
silicates, rare earth aluminates, and mixtures of two or more
thereof.
18. The green laminate of claim 16, wherein the heat treatment is
selected from the group consisting of hot pressing and hot
isostatic pressing.
19. An assembly configured for use in fabricating semiconductor
chips, the assembly comprising: a. a reactor; and, b. a
corrosion-resistant component including: i. a ceramic insulating
substrate; and, ii. a corrosion-resistant non-porous layer
associated with the ceramic insulating substrate, the
corrosion-resistant non-porous layer of a composition comprising at
least 15% by weight of a rare earth compound based on total weight
of the corrosion-resistant non-porous layer and is characterized by
a microstructure substantially devoid of microcracks and fissures,
and having: a thickness of at least 50 .mu.m; a porosity of at most
1%; and, an average grain size of at least 100 nm and at most 100
.mu.m.
20. The assembly of claim 19, wherein the ceramic insulating
substrate is selected from the group consisting of aluminum oxide,
aluminum nitride, silicon nitride, silicate-based materials and
mixtures of two or more thereof.
21. The assembly of claim 20, wherein the rare earth compound is
selected from the group consisting of yttrium oxide
(Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides, yttrium
oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof.
22. The assembly of claim 21, wherein the corrosion-resistant
non-porous layer is adhered to the ceramic insulating substrate and
has an adhesion strength of at least 20 MPa.
23. The assembly of claim 22, wherein the corrosion-resistant
non-porous layer has: a thickness of at least 100 .mu.m; a porosity
of at most 0.5%; an adhesion strength of at least 30 MPa; and, an
average grain size of at least about 300 nm and at most about 30
.mu.m.
24. The assembly of claim 19, further comprising at least one
interposing layer embedded in the ceramic insulating substrate, or
layered between the ceramic insulating substrate and the
corrosion-resistant non-porous layer.
25. The assembly of claim 24, wherein the at least one interposing
layer is selected from the group consisting of rare earth oxides,
rare earth silicates, rare earth aluminates, and mixtures of two or
more thereof.
26. The assembly of claim 25, wherein the at least one interposing
layer is ytterbium oxide (Yb.sub.2O.sub.3).
27. The assembly of claim 24, wherein the at least one interposing
layer comprises conducting materials.
28. The assembly of claim 27, wherein the at least one interposing
layer further comprises insulating materials.
29. The assembly of claim 24, wherein the at least one interposing
layer is selected from the group consisting of ytterbium oxide
(Yb.sub.2O.sub.3), molybdenum (Mo), tungsten (W), molybdenum
disilicide (MoSi.sub.2), tungsten carbide (WC), tungsten disilicide
(WSi.sub.2), and mixtures of two or more thereof.
30. The assembly of claim 19, wherein the reactor is a plasma etch
reactor configured for plasma etching and the corrosion-resistant
component is a lid configured for releasable engagement with the
plasma etch reactor; and, wherein the lid has a loss tangent of
less than 1.times.10.sup.-4.
31. The assembly of claim 19, wherein the reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a heater.
32. The assembly of claim 19, wherein the reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a showerhead.
33. The assembly of claim 31, wherein the substrate further
includes at least one interposing conductive layer embedded
therein, the conductive layer having a sheet resistivity of at most
10 Megaohm-cm and a coefficient thermal expansion difference of at
most 4.times.10.sup.-6/K relative to the coefficients of thermal
expansion for the ceramic insulating substrate and the
corrosion-resistant non-porous layer.
Description
CROSS-REFERENCE TO RELATED APPLICATION
[0001] This non-provisional patent application claims priority to
and the benefit of U.S. Provisional Patent Application Ser. No.
62/255,769 filed Nov. 16, 2015. The foregoing provisional patent
application is incorporated herein by reference in its entirety for
all purposes.
FIELD
[0002] The present disclosure relates generally to
corrosion-resistant components for the processing of equipment,
such as semiconductors, and to methods of making such
corrosion-resistant components.
BACKGROUND
[0003] The processing of semiconductors frequently involves
corrosive gases such as halogens in association with strong
electric and magnetic fields. This combination of a corrosive
environment and strong electric/magnetic fields generates a need
for corrosion-resistant insulators. It is generally accepted that
the most corrosion-resistant insulating materials for such
applications are rare earth compounds, such as yttrium oxide (also
known as "yttria"). Unfortunately, rare earth compounds tend to be
both expensive and mechanically weak. The industry therefore tends
to use coatings of rare earth compounds on less expensive
insulators like aluminum oxide.
[0004] Several different coating methods have been used for the
insulators. Physical vapor deposition (PVD) coatings have been
used. These have the drawback that they are costly to apply for
thicknesses of more than 10 .mu.m. Thick, dense layers tend to
spall due to internal stresses in the as-deposited coatings.
Strain-tolerant thick PVD coatings made are known to contain
fissures between crystallites that create the potential for
shedding particles. Chemical vapor deposition (CVD) for coating
application has been used, but it suffers the similar drawbacks.
High rate deposition tends to produce fissures between grains.
Denser coatings made by CVD are characterized by a grain size that
tends to be small, typically less than 100 nm. Aerosol deposition
has been used and it also suffers from cost limitations and an
inability to make thick coatings that do not spall. Thermal plasma
spray is the most widely used coating technology in the
semiconductor equipment industry, but it cannot produce rare-earth
coatings with porosity less than 1%, and therefore is prone to the
shedding of particles. Furthermore, plasma spray coatings commonly
contain a high density of microcracks (typically more than
100/mm.sup.2), and this, together with the porosity, leads to the
shedding of particles.
[0005] Ceramic lids are commonly interposed between induction coils
and induction plasma used for etching in the semiconductor
industry. Insulating rings surrounding the wafer chuck and other
chamber parts in etch and deposition equipment need to be
corrosion-resistant as well as stable, for the reasons outlined
above.
[0006] Another need in the semiconductor equipment industry is for
high temperature corrosion-resistant wafer heaters. These needs are
addressed by the corrosion-resistant components and assemblies of
the invention.
BRIEF SUMMARY
[0007] These and other needs are addressed by the various aspects,
embodiments, and configurations of the present disclosure.
[0008] Embodiments of the present disclosure include a
corrosion-resistant component configured for use with a
semiconductor processing reactor, the corrosion-resistant component
comprising: a) a ceramic insulating substrate; and, b) a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer
having a composition comprising at least 15% by weight of a rare
earth compound based on total weight of the corrosion-resistant
non-porous layer; and, the corrosion-resistant non-porous layer
characterized by a microstructure substantially devoid of
microcracks and fissures, and having an average grain size of at
least about 100 nm and at most about 100 .mu.m.
[0009] The corrosion-resistant component according to paragraph
[0008], wherein the ceramic insulating substrate is selected from
the group consisting of aluminum oxide, aluminum nitride, silicon
nitride, silicate-based materials and mixtures of two or more
thereof.
[0010] The corrosion-resistant component according to either
paragraph [0008] or [0009], wherein the rare earth compound is
selected from the group consisting of yttrium oxide (Y2O3), yttrium
silicates, yttrium fluorides, yttrium oxyfluorides, yttrium
aluminates, nitrides, complex nitride compounds, and combinations
of two or more thereof.
[0011] The corrosion-resistant component according to any of
paragraphs [0008]-[0010], wherein the corrosion-resistant
non-porous layer is adhered to the ceramic insulating substrate,
and the corrosion-resistant non-porous layer has: a porosity of at
most 1%; an adhesion strength of at least 20 MPa; and, a thickness
of at least 50 .mu.m.
[0012] The corrosion-resistant component according to any of
paragraphs [0008]-[0011], wherein the corrosion-resistant
non-porous layer has: a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; a thickness of at least 100 .mu.m;
and, an average grain size of at least about 300 nm and at most
about 30 .mu.m.
[0013] The corrosion-resistant component according to any of
paragraphs [0008]-[0012], wherein the ceramic insulating substrate
is aluminum oxide and the rare earth compound is a trivalent rare
earth oxide.
[0014] The corrosion-resistant component according to any of
paragraphs [0008]-[0013], wherein the ceramic insulating substrate
is aluminum nitride and the corrosion-resistant non-porous layer is
a rare earth silicate.
[0015] The corrosion-resistant component according to any of
paragraphs [0008]-[0014], wherein the corrosion-resistant component
is a lid configured for releasable engagement with a plasma etch
reactor and has a loss tangent of less than 1.times.10.sup.-4.
[0016] The corrosion-resistant component according to any of
paragraphs [0008]-[0015], further comprising at least one
interposing layer embedded in the ceramic insulating substrate, or
layered between the ceramic insulating substrate and the
corrosion-resistant non-porous layer.
[0017] The corrosion-resistant component according to any of
paragraphs [0008]-[0016], wherein the at least one interposing
layer is selected from the group consisting of rare earth oxides,
rare earth silicates, rare earth aluminates, and mixtures of two or
more thereof.
[0018] The corrosion-resistant component according to any of
paragraphs [0008]-[0017], wherein the at least one interposing
layer is ytterbium oxide (Yb.sub.2O.sub.3).
[0019] The corrosion-resistant component according to any of
paragraphs [0008]-[0018], wherein the at least one interposing
layer comprises conducting materials.
[0020] The corrosion-resistant component according to any of
paragraphs [0008]-[0019], wherein the at least one interposing
layer further comprises insulating materials.
[0021] The corrosion-resistant component according to any of
paragraphs [0008]-[0020], wherein the at least one interposing
layer is adhered to both the corrosion-resistant non-porous layer
and to the ceramic insulating substrate, and the
corrosion-resistant non-porous layer has: a porosity of at most 1%;
an adhesion strength of at least 20 MPa; and, a thickness of at
least 50 .mu.m.
[0022] Embodiments of the present disclosure also include a green
laminate configured for use with a semiconductor processing
reactor, the green laminate comprising: a first layer of green
sinterable material selected from the group consisting of aluminum
oxide, aluminum nitride, silicon nitride, silicate-based materials,
and mixtures of two or more thereof; a second layer of green
sinterable material selected from the group consisting of yttrium
oxide (Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides,
yttrium oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof; and, wherein
upon heat treatment of the green laminate, the second layer has a
porosity of at most 1% and an average grain size of at least about
100 nm and at most about 100 .mu.m.
[0023] The green laminate according to paragraph [0022], wherein
upon heat treatment of the green laminate, the second layer has a
porosity of at most 0.5% and an average grain size of at least
about 300 nm and at most about 30 .mu.m.
[0024] The green laminate according to either paragraph [0022] or
[0023], further comprising at least one interposing layer between
the first and second layers, wherein the at least one interposing
layer comprises green sinterable material selected from the group
consisting of rare earth oxides, rare earth silicates, rare earth
aluminates, and mixtures of two or more thereof.
[0025] The green laminate according to any of paragraphs
[0022]-[0024], wherein the heat treatment is selected from the
group consisting of hot pressing and hot isostatic pressing.
[0026] Embodiments of the present disclosure also include an
assembly configured for use in fabricating semiconductor chips, the
assembly comprising: a reactor; and, a corrosion-resistant
component including: a ceramic insulating substrate; and, a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer of a
composition comprising at least 15% by weight of a rare earth
compound based on total weight of the corrosion-resistant
non-porous layer and is characterized by a microstructure
substantially devoid of microcracks and fissures, and having: a
thickness of at least 50 .mu.m; a porosity of at most 1%; and, an
average grain size of at least 100 nm and at most 100 .mu.m.
[0027] The assembly according to paragraph [0026], wherein the
ceramic insulating substrate is selected from the group consisting
of aluminum oxide, aluminum nitride, silicon nitride,
silicate-based materials and mixtures of two or more thereof.
[0028] The assembly according to either paragraph [0026] or [0027],
wherein the rare earth compound is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds, and combinations of two or
more thereof.
[0029] The assembly according to any of paragraphs [0026]-[0028],
wherein the corrosion-resistant non-porous layer is adhered to the
ceramic insulating substrate and has an adhesion strength of at
least 20 MPa.
[0030] The assembly according to any of paragraphs [0026]-[0029],
wherein the corrosion-resistant non-porous layer has: a thickness
of at least 100 .mu.m; a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; and, an average grain size of at least
about 300 nm and at most about 30 .mu.m.
[0031] The assembly according to any of paragraphs [0026]-[0030],
further comprising at least one interposing layer embedded in the
ceramic insulating substrate, or layered between the ceramic
insulating substrate and the corrosion-resistant non-porous
layer.
[0032] The assembly according to any of paragraphs [0026]-[0031],
wherein the at least one interposing layer is selected from the
group consisting of rare earth oxides, rare earth silicates, rare
earth aluminates, and mixtures of two or more thereof.
[0033] The assembly according to any of paragraphs [0026]-[0032],
wherein the at least one interposing layer is ytterbium oxide
(Yb.sub.2O.sub.3).
[0034] The assembly according to any of paragraphs [0026]-[0033],
wherein the at least one interposing layer comprises conducting
materials.
[0035] The assembly according to any of paragraphs [0026]-[0034],
wherein the at least one interposing layer further comprises
insulating materials.
[0036] The assembly according to any of paragraphs [0026]-[0035],
wherein the at least one interposing layer is selected from the
group consisting of ytterbium oxide (Yb.sub.2O.sub.3), molybdenum
(Mo), tungsten (W), molybdenum disilicide (MoSi.sub.2), tungsten
carbide (WC), tungsten disilicide (WSi.sub.2), and mixtures of two
or more thereof.
[0037] The assembly according to any of paragraphs [0026]-[0036],
wherein the reactor is a plasma etch reactor configured for plasma
etching and the corrosion-resistant component is a lid configured
for releasable engagement with the plasma etch reactor; and,
wherein the lid has a loss tangent of less than
1.times.10.sup.-4.
[0038] The assembly according to any of paragraphs [0026]-[0037],
wherein the reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a heater.
[0039] The assembly according to any of paragraphs [0026]-[0038],
wherein the reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a showerhead.
[0040] The assembly according to any of paragraphs [0026]-[0039],
wherein the substrate further includes at least one interposing
conductive layer embedded therein, the conductive layer having a
sheet resistivity of at most 10 Megaohm-cm and a coefficient
thermal expansion difference of at most 4.times.10.sup.-6/K
relative to the coefficients of thermal expansion for the ceramic
insulating substrate and the corrosion-resistant non-porous
layer.
[0041] Embodiments of the present disclosure also include a
corrosion-resistant component configured for use with a
semiconductor processing reactor, the corrosion-resistant component
comprising: a) a ceramic insulating substrate; and, b) a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer
having a composition comprising at least 15% by weight of a rare
earth compound based on total weight of the corrosion-resistant
non-porous layer; and, the corrosion-resistant non-porous layer
characterized by a microstructure devoid of microcracks and
fissures, and having an average grain size of at least 100 nm and
at most 100 .mu.m.
[0042] The corrosion-resistant component according to paragraph
[0041], wherein the ceramic insulating substrate is selected from
the group consisting of aluminum oxide, aluminum nitride, silicon
nitride, silicate-based materials and mixtures of two or more
thereof.
[0043] The corrosion-resistant component according to either
paragraph [0041] or [0042], wherein the rare earth compound is
selected from the group consisting of yttrium oxide (Y2O3), yttrium
silicates, yttrium fluorides, yttrium oxyfluorides, yttrium
aluminates, nitrides, complex nitride compounds, and combinations
of two or more thereof.
[0044] The corrosion-resistant component according to any of
paragraphs [0041]-[0043], wherein the corrosion-resistant
non-porous layer is adhered to the ceramic insulating substrate,
and the corrosion-resistant non-porous layer has: a porosity of at
most 1%; an adhesion strength of at least 20 MPa; and, a thickness
of at least 50 .mu.m.
[0045] The corrosion-resistant component according to any of
paragraphs [0041]-[0044], wherein the corrosion-resistant
non-porous layer has: a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; a thickness of at least 100 .mu.m;
and, an average grain size of at least 300 nm and at most 30
.mu.m.
[0046] The corrosion-resistant component according to any of
paragraphs [0041]-[0045], wherein the ceramic insulating substrate
is aluminum oxide and the rare earth compound is a trivalent rare
earth oxide.
[0047] The corrosion-resistant component according to any of
paragraphs [0041]-[0046], wherein the ceramic insulating substrate
is aluminum nitride and the corrosion-resistant non-porous layer is
a rare earth silicate.
[0048] The corrosion-resistant component according to any of
paragraphs [0041]-[0047], wherein the corrosion-resistant component
is a lid configured for releasable engagement with a plasma etch
reactor and has a loss tangent of less than 1.times.10.sup.-4.
[0049] The corrosion-resistant component according to any of
paragraphs [0041]-[0048], further comprising at least one
interposing layer embedded in the ceramic insulating substrate, or
layered between the ceramic insulating substrate and the
corrosion-resistant non-porous layer.
[0050] The corrosion-resistant component according to any of
paragraphs [0041]-[0049], wherein the at least one interposing
layer is selected from the group consisting of rare earth oxides,
rare earth silicates, rare earth aluminates, and mixtures of two or
more thereof.
[0051] The corrosion-resistant component according to any of
paragraphs [0041]-[0050], wherein the at least one interposing
layer is ytterbium oxide (Yb.sub.2O.sub.3).
[0052] The corrosion-resistant component according to any of
paragraphs [0041]-[0051], wherein the at least one interposing
layer comprises conducting materials.
[0053] The corrosion-resistant component according to any of
paragraphs [0041]-[0052], wherein the at least one interposing
layer further comprises insulating materials.
[0054] The corrosion-resistant component according to any of
paragraphs [0041]-[0053], wherein the at least one interposing
layer is adhered to both the corrosion-resistant non-porous layer
and to the ceramic insulating substrate, and the
corrosion-resistant non-porous layer has: a porosity of at most 1%;
an adhesion strength of at least 20 MPa; and, a thickness of at
least 50 .mu.m.
[0055] Embodiments of the present disclosure also include a green
laminate configured for use with a semiconductor processing
reactor, the green laminate comprising: a first layer of green
sinterable material selected from the group consisting of aluminum
oxide, aluminum nitride, silicon nitride, silicate-based materials,
and mixtures of two or more thereof; a second layer of green
sinterable material selected from the group consisting of yttrium
oxide (Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides,
yttrium oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof; and, wherein
upon heat treatment of the green laminate, the second layer has a
porosity of at most 1% and an average grain size of at least 100 nm
and at most 100 .mu.m.
[0056] The green laminate according to paragraph [0055], wherein
upon heat treatment of the green laminate, the second layer has a
porosity of at most 0.5% and an average grain size of at least 300
nm and at most 30 .mu.m.
[0057] The green laminate according to either paragraph [0055] or
[0056], further comprising at least one interposing layer between
the first and second layers, wherein the at least one interposing
layer comprises green sinterable material selected from the group
consisting of rare earth oxides, rare earth silicates, rare earth
aluminates, and mixtures of two or more thereof.
[0058] The green laminate according to any of paragraphs
[0055]-[0057], wherein the heat treatment is selected from the
group consisting of hot pressing and hot isostatic pressing.
[0059] Embodiments of the present disclosure also include an
assembly configured for use in fabricating semiconductor chips, the
assembly comprising: a reactor; and, a corrosion-resistant
component including: a ceramic insulating substrate; and, a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer of a
composition comprising at least 15% by weight of a rare earth
compound based on total weight of the corrosion-resistant
non-porous layer and is characterized by a microstructure devoid of
microcracks and fissures, and having: a thickness of at least 50
.mu.m; a porosity of at most 1%; and, an average grain size of at
least 100 nm and at most 100 .mu.m.
[0060] The assembly according to paragraph [0059], wherein the
ceramic insulating substrate is selected from the group consisting
of aluminum oxide, aluminum nitride, silicon nitride,
silicate-based materials and mixtures of two or more thereof.
[0061] The assembly according to either paragraph [0059] or [0060],
wherein the rare earth compound is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds, and combinations of two or
more thereof.
[0062] The assembly according to any of paragraphs [0059]-[0061],
wherein the corrosion-resistant non-porous layer is adhered to the
ceramic insulating substrate and has an adhesion strength of at
least 20 MPa.
[0063] The assembly according to any of paragraphs [0059]-[0062],
wherein the corrosion-resistant non-porous layer has: a thickness
of at least 100 .mu.m; a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; and, an average grain size of at least
300 nm and at most 30 .mu.m.
[0064] The assembly according to any of paragraphs [0059]-[0063],
further comprising at least one interposing layer embedded in the
ceramic insulating substrate, or layered between the ceramic
insulating substrate and the corrosion-resistant non-porous
layer.
[0065] The assembly according to any of paragraphs [0059]-[0064],
wherein the at least one interposing layer is selected from the
group consisting of rare earth oxides, rare earth silicates, rare
earth aluminates, and mixtures of two or more thereof.
[0066] The assembly according to any of paragraphs [0059]-[0065],
wherein the at least one interposing layer is ytterbium oxide
(Yb.sub.2O.sub.3).
[0067] The assembly according to any of paragraphs [0059]-[0066],
wherein the at least one interposing layer comprises conducting
materials.
[0068] The assembly according to any of paragraphs [0059]-[0067],
wherein the at least one interposing layer further comprises
insulating materials.
[0069] The assembly according to any of paragraphs [0059]-[0068],
wherein the at least one interposing layer is selected from the
group consisting of ytterbium oxide (Yb.sub.2O.sub.3), molybdenum
(Mo), tungsten (W), molybdenum disilicide (MoSi.sub.2), tungsten
carbide (WC), tungsten disilicide (WSi.sub.2), and mixtures of two
or more thereof.
[0070] The assembly according to any of paragraphs [0059]-[0069],
wherein the reactor is a plasma etch reactor configured for plasma
etching and the corrosion-resistant component is a lid configured
for releasable engagement with the plasma etch reactor; and,
wherein the lid has a loss tangent of less than
1.times.10.sup.-4.
[0071] The assembly according to any of paragraphs [0059]-[0070],
wherein the reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a heater.
[0072] The assembly according to any of paragraphs [0059]-[0071],
wherein the reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a showerhead.
[0073] The assembly according to any of paragraphs [0059]-[0072],
wherein the substrate further includes at least one interposing
conductive layer embedded therein, the conductive layer having a
sheet resistivity of at most 10 Megaohm-cm and a coefficient
thermal expansion difference of at most 4.times.10.sup.-6/K
relative to the coefficients of thermal expansion for the ceramic
insulating substrate and the corrosion-resistant non-porous
layer.
[0074] Embodiments of the present disclosure include a method for
preparing a corrosion-resistant component for use with a
semiconductor processing reactor, comprising: laying up a thinner
layer of a sinterable powder composition comprising at least 15% by
weight based on total weight of the thinner layer of a rare earth
compound, and a thicker layer of sinterable substrate material to
form a pre-laminate; and, heat treating the pre-laminate to form a
corrosion-resistant component including a corrosion-resistant
non-porous outermost layer characterized by a microstructure devoid
of microcracks and fissures, and having an average grain size of at
least 100 nm and at most 100 .mu.m.
[0075] The method according to paragraph [0074], wherein heat
treating is selected from the group consisting of hot pressing and
hot isostatic pressing.
[0076] The method according to either paragraph [0074] or [0075],
wherein the sinterable substrate material is selected from the
group consisting of aluminum oxide, aluminum nitride,
silicate-based materials, and mixtures of two or more thereof.
[0077] The method according to any of paragraphs [0074]-[0076],
wherein the rare earth compound is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds and combinations of two or more
thereof.
[0078] The method according to any of paragraphs [0074]-[0077],
wherein the sinterable substrate material is aluminum oxide and the
rare earth compound is a trivalent rare earth oxide.
[0079] The method according to any of paragraphs [0074]-[0078],
wherein the sinterable substrate material is aluminum nitride and
the rare earth compound is a rare earth silicate.
[0080] The method according to any of paragraphs [0074]-[0079],
wherein the corrosion-resistant component is a lid configured for
releasable engagement with a plasma etch reactor.
[0081] The method according to any of paragraphs [0074]-[0080],
wherein the lid has a has a loss tangent of less than
1.times.10.sup.-3.
[0082] The method according to any of paragraphs [0074]-[0081],
wherein the lid has a has a loss tangent of less than
1.times.10.sup.-4.
[0083] The method according to any of paragraphs [0074]-[0082],
further comprising laying up at least one additional sinterable
powder composition layer interposed between the rare earth compound
thinner layer and the substrate material thicker layer, prior to
heat treating.
[0084] The method according to any of paragraphs [0074]-[0083],
wherein the at least one additional sinterable powder composition
comprises a compound or metal having a coefficient thermal
expansion difference of at most 4.times.10.sup.-6/K relative to the
coefficients of thermal expansion for the ceramic insulating
substrate and the corrosion-resistant non-porous outermost
layer.
[0085] The method according to any of paragraphs [0074]-[0084],
wherein the at least one additional sinterable powder composition
comprises a compound or metal selected from the group consisting of
ytterbium oxide (Yb.sub.2O.sub.3), molybdenum (Mo), tungsten (W),
niobium (Nb), molybdenum disilicide (MoSi.sub.2), tungsten carbide
(WC), tungsten disilicide (WSi.sub.2), titanium carbide (TiC),
titanium nitride (TiN), and mixtures of two or more thereof.
[0086] The method according to any of paragraphs [0074]-[0085],
wherein the at least one additional sinterable powder composition
further comprises an insulating material selected from the group
consisting of alumina, aluminum nitride, aluminates, silicates and
mixtures of two or more thereof.
[0087] The method according to any of paragraphs [0074]-[0086],
wherein the at least one additional sinterable powder composition
is ytterbium oxide (Yb.sub.2O.sub.3).
[0088] The method according to any of paragraphs [0074]-[0087],
wherein the at least one additional sinterable powder composition
comprises conducting materials.
[0089] The method according to any of paragraphs [0074]-[0088],
wherein the at least one additional sinterable powder composition
further comprises insulating materials.
[0090] The method according to any of paragraphs [0074]-[0089],
wherein the semiconductor processing reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a heater.
[0091] The method according to any of paragraphs [0074]-[0090],
wherein the semiconductor processing reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a showerhead.
[0092] The method according to any of paragraphs [0074]-[0091],
wherein the sinterable substrate material further includes at least
one interposing conductive layer embedded therein, the conductive
layer having a sheet resistivity of at most 10 Megaohm-cm and a
coefficient thermal expansion difference of at most
4.times.10.sup.-6/K relative to the coefficients of thermal
expansion for the ceramic insulating substrate and the
corrosion-resistant non-porous outermost layer.
BRIEF DESCRIPTION OF THE DRAWINGS
[0093] FIG. 1A illustrates a cross-sectional view of an embodiment,
such as a lid, including a corrosion-resistant component according
to an example aspect of the invention;
[0094] FIG. 1B illustrates a cross-sectional view of an embodiment,
such as a lid, including a corrosion-resistant component according
to another example aspect of the invention;
[0095] FIG. 2 illustrates an assembly for plasma etching of
semiconductor chips, including a corrosion-resistant lid according
to an example aspect of the invention;
[0096] FIG. 3 illustrates a cross-sectional view of a
corrosion-resistant wafer heater according to an example aspect of
the invention; and,
[0097] FIG. 4 illustrates a chemical vapor deposition reactor
assembly including a wafer heater and a showerhead, each including
a corrosion-resistant non-porous layer, according to an example
aspect of the invention.
DETAILED DESCRIPTION
[0098] A ceramic substrate and a corrosion-resistant layer
comprising a rare earth compound are sintered together to form a
dense corrosion-resistant laminate or corrosion-resistant
component. This is to solve the problem of coatings (via plasma
spray coating operation, for example) being applied to previously
sintered substrates, wherein the coating subsequently suffers from
problems such as spalling or shedding particles during use. In an
example aspect, the heat treating of a thin rare earth compound
layer on a suitable substrate material provides a
corrosion-resistant component. In another example aspect, the rare
earth compound is yttrium oxide and the substrate material is a
ceramic, such as aluminum oxide. In yet another example aspect, the
rare earth compound comprises a rare earth silicate such as yttrium
silicate on an aluminum nitride substrate. In an example aspect, a
corrosion-resistant layer including a rare earth compound is
co-sintered with insulating substrate materials to form
corrosion-resistant ceramic lids, for example, that are commonly
interposed between induction coils and induction plasma used for
etching. In other example aspects, corrosion-resistant components
useful as insulating rings surrounding the wafer chuck and other
chamber parts in etch and deposition reactors, such as wafer
heaters and deposition showerheads, also benefit from this
technology. Components, assemblies and methods of the present
disclosure provide a way to meet the need for physically and
chemically stable, corrosion-resistant layers and parts such as
ceramic lids integral to the plasma reactors used in the
semiconductor industry.
[0099] As used herein, various terms are defined as follows.
"Alumina" is commonly understood to be aluminum oxide,
substantially comprising Al.sub.2O.sub.3. "Yttria" is commonly
understood to be yttrium oxide, substantially comprising
Y.sub.2O.sub.3. "Ytterbia" is commonly understood to be ytterbium
oxide, substantially comprising Yb.sub.2O.sub.3. The term
"substantially" generally refers a purity of 90 wt %, preferably 91
wt % or 92 wt % or 93 wt % or 94 wt % or 95 wt % or 96 wt % or 97
wt % or 98 wt % or 99 wt % or about 100 wt %. The term "about"
generally refers to plus or minus 10% of the indicated number. For
example, "about 10%" may indicate a range of 9% to 11%, and "about
20" may mean from 18-22. Other meanings of "about" may be apparent
from the context, such as rounding off, so, for example "about 1"
may also mean from 0.5 to 1.4. The term "soak" (see Tables in the
Examples) refers to the holding time at a particular temperature or
pressure in a hot pressing cycle.
[0100] Other definitions include the following. "Adhesion strength"
is measured by the ASTM C633 method. "Loss tangent" is the ratio of
the imaginary part of the dielectric constant to the real part; it
is directly proportional to the power absorbed by the component.
"Color" is described using the 1976 CIELAB color space: this
reduces colors to a lightness/darkness variable L*, for which
absolute black is 0 and complete white is 100, and other parameters
a* and b* which describe the hue of the object. "Porosity" is
measured by image analysis of a polished section, polished
according to the following scheme (polishing supplies provided by
Struers, Inc.): (i) 60 .mu.m diamond: as needed to flatten the
surface; (ii) 15 .mu.m diamond, fixed abrasive pad: 2 min; (iii) 9
.mu.m diamond, Largo (plastic) pad: 8 min; (iv) 3 .mu.m diamond,
DAC (nylon) pad: 6 min; and, (v) 1 .mu.m diamond, napped cloth: 3
min. "Grain size" is measured by the by ASTM-E112 method. "Green"
or "unsintered" ceramics as referred to herein include ceramic
materials or powders which have not been densified via a high
temperature thermal process. "Sintered" or "Cosintered" refers to
one or more ceramic materials that have been exposed to a high
temperature thermal process to promote sintering. "Sintering" is a
thermal or heat treatment process to promote material transport and
densification through the gradual elimination of porosity. The
sintering process is used to produce materials with controlled
microstructure and porosity. "Coating" is a layer applied to a
substrate, for example, a sintered substrate. "Laminate" or
"composite laminate" is an assembly of layers that are joined via a
process such as sintering, for example. "Component" is a part or
product.
[0101] A reactor for semiconductor fabrication or semiconductor
processing is useful for etching or deposition or both. A reactor
is referred to interchangeably herein as a semiconductor processing
reactor, a semiconductor fabrication reactor, or simply as reactor.
Reactors are useful for plasma etching or deposition or both. In an
example aspect, both the ceramic insulating substrate and the
corrosion-resistant non-porous layer are resistant to a plasma
etching treatment employed in semiconductor processing. In an
example aspect, the corrosion-resistant component is a lid for a
plasma etch reactor. Reactors used for deposition periodically run
an etching process for cleaning of the reactor. In an example
aspect, the reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a heater. In another example aspect, the reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a showerhead.
[0102] Ceramics are inorganic, non-metallic materials known for
their ability to withstand high temperatures. Ceramics include
oxides, non-oxides and composites (combinations of oxides and
non-oxides). Oxides include, in non-limiting examples, alumina,
glass-ceramics, beryllia, mullite, ceria, and zirconia. In a
preferred embodiment the ceramic oxide is alumina
(Al.sub.2O.sub.3). Non-oxides include carbides, borides, nitrides,
and silicides. In another preferred embodiment, the non-oxide is a
nitride, such as aluminum nitride (AlN). Ceramic oxides,
non-oxides, and composites are useful as substrates.
[0103] A corrosion-resistant layer including a rare-earth element
or compound is advantageously joined with a ceramic substrate
and/or other layers to provide a laminate, wherein the outermost
layer is corrosion-resistant and non-porous. Examples of rare-earth
compounds include, but are not limited to trivalent rare earth
oxides such as in an example embodiment, yttrium oxide
(Y.sub.2O.sub.3). In other example embodiments, the rare earth
compound is selected from the group consisting of yttrium oxide,
yttrium silicates, yttrium fluorides, yttrium oxyfluorides, yttrium
aluminates, nitrides, complex nitride compounds, and combinations
of two or more thereof. In an example aspect, the rare earth
compound is Y.sub.3Si.sub.3O.sub.10F. In other example aspects, the
rare earth compound is a complex nitride compound such as
YN.Si.sub.3N.sub.4 or YN.AlN.Y.sub.2O.sub.3.2SiO.sub.2, for
example.
[0104] Sintering aids, as known to one of skill in the art, are
useful for example to minimize porosity, reduce grain size, and/or
to enable less extreme processing conditions to be employed (for
example, lower pressures in hot pressing) for sintering. In an
example aspect, a sintering aid is added to the rare-earth
compound. In an example aspect, the sintering aid added to the
rare-earth compound is an oxide of tetravalent elements (e.g. Zr,
Hf, Ce). In an example aspect, the amount of sintering aid added to
the rare-earth compound is in the range from about 300 ppm to about
20% by weight based upon total weight of the rare-earth compound;
in another example aspect from about 0.5% by weight to about 15% by
weight based upon total weight of the rare-earth compound. In an
example aspect, the amount of sintering aid added to the rare-earth
compound is about 1% by weight, or about 2% by weight, or about 5%
by weight, or about 10% by weight, or about 15% by weight. In an
example aspect, the sintering aid added to the rare-earth compound
is ZrO.sub.2 or HfO.sub.2. In an example aspect, where the
rare-earth compound is yttria, for example, ZrO.sub.2 is used as a
sintering aid in the amount of about 1% by weight based upon total
weight of the rare-earth compound. In another example aspect,
ZrO.sub.2 is used as a sintering aid in the amount of about 15% by
weight based upon total weight of the rare-earth compound. In an
example aspect for processing large parts such as a lid, for which
maintaining pressure levels is challenging, about 1% by weight
sintering aid is added to the rare-earth compound based upon total
weight of the rare-earth compound.
[0105] Interposer layers can be placed between the substrate and
the rare-earth compound containing corrosion-resistant layer in
assembling the laminate. In an example aspect, at least one
interposer layer between a yttria layer and an alumina substrate is
useful in order to detect wear of the outermost corrosion-resistant
layer. Interposer layers may also advantageously include a
rare-earth element or compound. In one embodiment, ytterbium oxide
(Yb.sub.2O.sub.3) is used as an interposer layer since its
fluorescence at infrared (IR) wavelengths can be used to detect
corrosion-resistant layer wear without producing a cosmetic color
change of the material. As owners of semiconductor equipment
frequently care about cosmetic issues, Yb.sub.2O.sub.3 layers offer
the advantage of not being visible to the human eye (in other words
colorless) while allowing detection of wear by irradiating with
appropriate IR wavelengths and observing the fluorescence. The
thickness of interposer layer(s) depends on function; typically
interposer layers are at most about 2 mm in thickness. In an
example aspect, interposer layers such as conductive layers or
bonding layers function acceptably at thicknesses of less than 10
.mu.m.
[0106] Optionally, it may also be advantageous to include metal
layers in the ceramic lid, insulating rings and other chamber parts
that are commonly found in etching and deposition equipment. As
noted above, ceramic lids, which are also referred to as ceramic
windows or simply as lids or windows interchangeably herein, are
commonly interposed between induction coils and induction plasma
used for etching. The electrical resistance of a metal layer could
also serve to monitor the temperature of the lid, thus enabling
feedback control over its temperature. Embedding or interposing the
layers within the lid or component simplifies the assembly of the
system and also improves shielding and the coupling of the heat to
the lid.
[0107] It is important to choose the materials of the embedded
layers to match the thermal expansion coefficient of the bulk
composite as well as to the individual layer(s) of the composite as
mismatches tend to lead to delayed delamination within the
component. Thermal expansion mismatches can be considered close or
acceptable if the difference in thermal expansion coefficients is
at most 4.times.10.sup.-6/K relative to the coefficients for the
ceramic insulating substrate and the corrosion-resistant non-porous
layer. In an example aspect, the at least one interposing layer is
chosen to be a material having a thermal expansion coefficient
difference of at most at most 4.times.10.sup.-6/K relative to the
coefficients for the ceramic insulating substrate and the
corrosion-resistant non-porous layer. Thermal expansion mismatches
can often be helped by making the layer a composite of several
different materials, whose combined thermal expansion matches the
expansion of the bulk of the part. In an example aspect, MoSi.sub.2
is a particularly suitable conductive metal, because its thermal
expansion is close to that of alumina, and it does not react with
alumina at the high processing temperatures.
[0108] Since the components of the invention may operate in strong
electromagnetic fields, minimizing the loss tangent is an important
consideration. In an example aspect, the corrosion-resistant
component has a loss tangent of the component of at most
1.times.10.sup.-3, preferably at most 1.times.10.sup.-4. A
component having a loss tangent of at most 1.times.10.sup.-4 is
substantially transparent to radio-frequency (RF) energy. Excessive
carbon content in the parts tends to promote high loss tangent and
therefore carbon content should be minimized. Free carbon contents
in excess of 2000 ppm are undesirable. In one embodiment the carbon
content is at most 1500 ppm. In another embodiment the carbon
content is at most 1000 ppm. In a further embodiment the carbon
content is at most 500 ppm. In yet another embodiment the carbon
content is at most 100 ppm.
[0109] The presence or exposure to certain elements during the
semiconductor processing, for example, can be undesirable. In
applications for which light-colored ceramic components are
desired, due to industry users being sensitive to the color of the
components or parts as with semiconductor processing, undesired
elements are to be avoided. Metal contamination in the parts (which
affects the properties of transistors in the wafers processed in
the equipment) can be visible as dark spots on the parts. Thus
lighter colors for the parts are preferred as the spots show up
more clearly. This enables problem or unacceptable parts to be
identified and discarded before use. In an example aspect, the
corrosion-resistant component has a CIE Lab color L* parameter of
at least 50. In another example aspect, the corrosion-resistant
component has a CIE Lab color L* parameter of at least 80.
[0110] First row transition elements such as V, Cr, Mn, Fe, Co, Ni,
Cu, and Zn, for example, diffuse relatively quickly through silicon
and can alter the electrical properties of devices. The presence of
Au and Ag can cause similar problems. In addition, elements such as
Li, Na, and K diffuse quickly through silica and can affect the
charge density on device gates. The corrosion-resistant component
of the invention is substantially contaminant free. Total
concentration of undesirable elements in the raw materials for
making corrosion-resistant components is to be minimized. The total
concentration of these undesirable elements should be substantially
less than 1 at %. In an example aspect, the total concentration of
undesirable elements in raw materials used in making of the
corrosion-resistant components is at most 1 at %.
[0111] Layer thickness for the outermost layer may be tailored to
the component and its application for use. The outermost layer is
the corrosion-resistant non-porous layer. Depending upon use, the
outermost layer may be oriented toward the inside of a chamber or
reactor, for example. For lids or windows, which are typically
larger than 500 mm in diameter, relatively thick layers are
desired. The as-fired profile of such a large component may depart
by a millimeter or more from the desired profile; therefore, it is
desirable for the as-fired thickness of the outermost layer to be
substantially more than one millimeter thick, in order to ensure
the presence of enough outermost material even after grinding.
Thinner layers are more appropriately used on smaller parts,
because departures from the true form are typically less.
[0112] One example aspect of the invention is directed to a
corrosion-resistant component configured for use with a
semiconductor processing reactor, the corrosion-resistant component
comprising: a) a ceramic insulating substrate; and, b) a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate, the corrosion-resistant non-porous layer
having a composition comprising at least 15% by weight of a rare
earth compound based on total weight of the corrosion-resistant
non-porous layer; and, the corrosion-resistant non-porous layer
characterized by a microstructure substantially devoid of
microcracks and fissures, and having an average grain size of at
least about 100 nm and at most about 100 .mu.m. In an example
aspect, the corrosion-resistant non-porous layer associated with
the ceramic insulating substrate is adhered to the substrate. In an
example aspect, the corrosion-resistant non-porous layer is adhered
directly to the substrate. In another example aspect, the
corrosion-resistant non-porous layer is adhered indirectly to the
substrate, for example with interposing layers therebetween.
[0113] The microstructure of the corrosion-resistant non-porous
layer is important to the durability and performance of the
component. A component or laminate including a non-porous layer
free of microcracks and fissures does not suffer deleterious
effects such as particle shedding. In an example aspect, the
corrosion-resistant non-porous layer is characterized by a
microstructure devoid of microcracks and fissures. In another
example aspect, the corrosion-resistant non-porous layer is
characterized by a microstructure substantially devoid of
microcracks and fissures. In an example aspect, the
corrosion-resistant non-porous layer has microcracks and fissures
of less than 50 per mm.sup.2, in an example aspect less than 10 per
mm.sup.2, in another example aspect less than 5 per mm.sup.2, and
in yet another example aspect less than 1 per mm.sup.2. In an
example aspect, the corrosion-resistant non-porous layer is
characterized by a microstructure having microcracks and fissures
of at most 1 per mm.sup.2, as quantified by image analysis, for
example, or other methods as known in the art. Whereas microcracks
and fissures are deleterious to the microstructural integrity of
the corrosion-resistant non-porous layer, second phases in the
microstructure may conversely increase strength of the layer (refer
to Example 10).
[0114] In an example aspect, grain size of the corrosion-resistant
non-porous layer is important to the performance of the component.
Generally, corrosion occurs fastest at grain boundaries, thus
materials with larger grain sizes corrode more slowly. In addition,
if corrosion on boundaries is relatively rapid, entire grains can
be dislodged by grain boundary corrosion. This is also referred to
herein as particle loss or shedding. In an example aspect, the
corrosion-resistant component includes a corrosion-resistant
non-porous layer having an average grain size as measured by
ASTM-E112 of at least 100 nm. In an example aspect, the
corrosion-resistant non-porous layer is characterized as having an
average grain size of at least 100 nm, or at least 150 nm, or at
least 200 nm, or at least 300 nm, or at least 500 nm. However,
problems may develop with overly large grain sizes, for example,
the size of flaws weakening the material scales as the grain size;
therefore, grain sizes larger than 100 .mu.m are also undesirable.
In an example aspect, the corrosion-resistant non-porous layer is
characterized as having an average grain size of at most 100 .mu.m,
or at most 30 .mu.m, or at most 10 .mu.m, or at most 1 .mu.m, or at
most 750 nm. Alternatively, the average grain size of the
corrosion-resistant non-porous layer is in the range of about 100
nm to about 100 .mu.m, preferably about 200 nm to about 50 .mu.m,
more preferably about 300 nm to about 30 .mu.m. In another example
aspect, the average grain size of the corrosion-resistant
non-porous layer is at least 300 nm and at most 30 .mu.m.
[0115] In an example aspect, the corrosion-resistant component
includes a corrosion-resistant non-porous layer having: a) a
porosity of .ltoreq.2%, preferably .ltoreq.1% or .ltoreq.0.9% or
.ltoreq.0.8% or .ltoreq.0.7% or .ltoreq.0.6% or .ltoreq.0.5% or
.ltoreq.0.4% or .ltoreq.0.3% or .ltoreq.0.2% or .ltoreq.0.1%; and
b) an adhesion strength of .gtoreq.15 MPa, preferably .gtoreq.20
MPa or .gtoreq.25 MPa or .gtoreq.30 MPa or .gtoreq.35 MPa or
.gtoreq.40 MPa; and c) a layer thickness of .gtoreq.50 .mu.m,
preferably .gtoreq.100 .mu.m or .gtoreq.150 .mu.m or .gtoreq.200
.mu.m or .gtoreq.250 .mu.m or .gtoreq.300 .mu.m. Layer thickness,
as mentioned previously, may be tailored to the application of use
or component specifications desired. Alternatively, the layer
thickness can be in the range of about 50 to about 500 .mu.m,
preferably about 100 to about 400 .mu.m, more preferably about 150
to about 300 .mu.m. In an example aspect, the corrosion-resistant
non-porous layer has: a porosity of at most 1%; an adhesion
strength of at least 20 MPa; and, a layer thickness of at least 50
.mu.m. In another example aspect, the corrosion-resistant
non-porous layer has: a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; and, a layer thickness of at least 100
.mu.m.
[0116] FIGS. 1A and 1B illustrate cross-sectional schematic views
of example aspects of corrosion-resistant components. In FIG. 1A,
corrosion-resistant component 100 includes substrate 110 having
corrosion-resistant non-porous layer 120 adjacent to the substrate
110 where layer 120 provides an outermost layer for the component.
Layer 120 has thickness t.sub.1. In FIG. 1B, corrosion-resistant
component 150 includes substrate 110 having interposing layer 130
situated between substrate 110 and corrosion-resistant non-porous
layer 120. Layer 130 has thickness t.sub.2. In one embodiment of
the corrosion-resistant component both the substrate and the
corrosion-resistant non-porous layer are resistant to the plasma
etching conditions employed in semiconductor processing.
[0117] In an example aspect, as shown in FIG. 1A,
corrosion-resistant component 100 includes non-porous
corrosion-resistant layer 120 comprising a rare earth compound. In
an example aspect, layer 120 comprises a trivalent rare earth
oxide. In another example aspect, the rare earth compound is
selected from the group consisting of yttrium oxide
(Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides, yttrium
oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof. In another
example aspect, the rare earth compound is a complex nitride
compound such as, for example, YN.Si.sub.3N.sub.4 or
YN.AlN.Y.sub.2O.sub.3.2SiO.sub.2.
[0118] In an example aspect, the corrosion-resistant component
includes ceramic insulating substrate 110, as shown also in FIG.
1A, selected from the group consisting of aluminum oxide
("alumina", also Al.sub.2O.sub.3), aluminum nitride, silicon
nitride, silicate-based materials and mixtures of two or more
thereof. In an example aspect, for applications requiring high
strength, for example, the substrate may further include zirconia
(ZrO.sub.2). In an example aspect, the ceramic insulating substrate
is aluminum oxide. In an example aspect, the ceramic insulating
substrate consists essentially of aluminum oxide. In an example
aspect, the ceramic insulating substrate is aluminum oxide and the
rare earth compound is a trivalent rare earth oxide. In another
example aspect, the ceramic insulating substrate is aluminum
nitride and the corrosion-resistant non-porous layer is a rare
earth silicate.
[0119] In an example aspect, the corrosion-resistant non-porous
layer is adhered to the ceramic insulating substrate, and the
corrosion-resistant non-porous layer has: a porosity of at most 1%;
an adhesion strength of at least 20 MPa; and, a thickness of at
least 50 .mu.m. In another example aspect, the corrosion-resistant
non-porous layer is adhered to the ceramic insulating substrate,
and the corrosion-resistant non-porous layer has: a porosity of at
most 0.5%; an adhesion strength of at least 30 MPa; a thickness of
at least 100 .mu.m; and, an average grain size of at least about
300 nm and at most about 30 .mu.m.
[0120] In an example aspect, corrosion-resistant component 100 is a
lid configured for releasable engagement with a plasma etch
reactor. In an example aspect, the corrosion-resistant component or
lid has a loss tangent of less than 1.times.10.sup.-4. In an
example aspect, ceramic insulating substrate 110 and
corrosion-resistant non-porous layer 120 are substantially
transparent to radio-frequency (RF) energy. In an example aspect,
ceramic insulating substrate 110 and corrosion-resistant non-porous
layer 120 are transparent to radio-frequency (RF) energy.
[0121] In an example aspect, corrosion-resistant component 150, as
shown in FIG. 1B, includes at least one interposing layer 130
selected from the group consisting of rare earth oxides, rare earth
silicates, rare earth aluminates, and mixtures of two or more
thereof. In an example aspect, the at least one interposing layer
130 is ytterbium oxide (Yb.sub.2O.sub.3). In an example aspect, the
at least one interposing layer comprises conducting materials. In
an example aspect, the at least one interposing layer further
comprises insulating materials.
[0122] In an example aspect, the at least one interposing layer is
adhered to both the corrosion-resistant non-porous layer and to the
ceramic insulating substrate, and the corrosion-resistant
non-porous layer has: a porosity of at most 1%; an adhesion
strength of at least 20 MPa; and, a thickness of at least 50 .mu.m.
In another example aspect, the at least one interposing layer is
adhered to both the corrosion-resistant non-porous layer and to the
ceramic insulating substrate, and the corrosion-resistant
non-porous layer has: a porosity of at most 0.5%; an adhesion
strength of at least 30 MPa; a thickness of at least 100 .mu.m;
and, an average grain size of at least about 300 nm and at most
about 30 .mu.m.
[0123] In an example aspect, at least one interposing layer is
either embedded in the ceramic insulating substrate 110 (see FIG.
3, layers 340, 360), or between and adhered to both the substrate
and the corrosion-resistant non-porous layer 120 (see FIG. 1B). In
an example aspect, the interposing layer is selected from the group
consisting of rare earth oxides, rare earth silicates, rare earth
aluminates and mixtures of two or more thereof. A rare earth oxide
suitable as an at least one interposing layer is ytterbium oxide
(Yb.sub.2O.sub.3). In another example aspect, the interposing layer
comprises conducting materials, which can optionally further
comprise insulating materials. With regard to the conducting
materials, for most applications direct current (DC) or low
frequency, for example less than 100 MHz, conductivity is required.
Conducting metal layers are useful as actively driven electrodes or
as a passive RF shield. The insulating materials are generally
selected from the group consisting of alumina, aluminum nitride,
silicon nitride, aluminates, silicates, and mixtures of two or more
thereof, although any material compatible with the processing of
the part and the metals in the layer could be also used; the
reasons to add materials to the conducting layer can include
obtaining better thermal expansion match to the rest of the part
and improving the adhesion between the layer and the rest of the
part. In the case where conducting materials are used, the layer
will usually have large openings in it to allow RF energy to pass
through. In other words, in an example aspect, an interposing layer
such as a conductive layer is non-continuous. In one embodiment of
the corrosion-resistant component the substrate and the
corrosion-resistant non-porous layer are substantially transparent
to radio-frequency (RF) energy.
[0124] In an example aspect, and prior to heat treatment, a green
laminate configured for use with a semiconductor processing reactor
comprises a first layer of green sinterable material and a second
layer of green sinterable material including a rare earth compound.
In an example aspect, the first layer of green sinterable material
is selected from the group consisting of aluminum oxide, aluminum
nitride, silicon nitride, silicate-based materials, and mixtures of
two or more thereof. In an example aspect, the second layer of
green sinterable material comprises a trivalent rare earth oxide.
In another example aspect, the second layer comprises a rare earth
compound selected from the group consisting of yttrium oxide
(Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides, yttrium
oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds, and combinations of two or more thereof. In an example
aspect, upon heat treatment of the laminate, the second layer has a
porosity of at most 1% and an average grain size of at least 100 nm
and at most 100 .mu.m. In another example aspect, upon heat
treatment of the laminate, the second layer has a porosity of at
most 0.5%. In an example aspect, upon heat treatment of the
laminate, the average grain size of the second layer is at least
300 nm and at most 30 .mu.m.
[0125] In an example aspect, the green laminate further includes at
least one interposing layer between the first and second layers,
wherein the interposing layer comprises green sinterable material
selected from the group consisting of rare earth oxides, rare earth
silicates, rare earth aluminates, and mixtures of two or more
thereof. In an example aspect, the green laminate further includes
at least one interposing layer wherein the at least one interposing
layer comprises conducting materials. In an example aspect, the
green laminate further includes at least one interposing layer
wherein the at least one interposing layer comprises insulating
materials. In an example aspect, the heat treatment for the green
laminate is selected from the group consisting of hot pressing and
hot isostatic pressing. After heat treatment, the heat treated or
sintered laminate including interposing layer(s) has an adhesion
strength of at least 15 MPa, or at least 20 MPa, or at least 25
MPa, or at least 30 MPa, or at least 35 MPa, or at least 40
MPa.
[0126] FIG. 2 illustrates an example aspect of an assembly
configured for use in plasma etching semiconductor wafers. Plasma
etch reactor assembly 200 includes plasma etch reactor 250.
Alternating magnetic fields generated by induction coils 240 extend
through lid 225, creating electric fields inside reactor 250
directly under lid 225, which in turn create the etch plasma.
Corrosion-resistant lid 225 is configured for releasable engagement
with plasma etch reactor 250. Lid 225 includes a
corrosion-resistant ceramic insulating substrate 210 having an
inner surface and an outer surface; and, further includes
corrosion-resistant non-porous layer 220, which is adjacent to the
inner surface of substrate 210. Corrosion-resistant non-porous
layer 220, having inner and outer planar surfaces, is positioned so
that the inner planar surface of layer 220 faces the interior of
reactor 250. Optionally, interposing layer(s) (example layer 130 as
shown in FIG. 1B) are situated between substrate 210 and
corrosion-resistant non-porous layer 220. In an example aspect,
layer 220 comprising a rare earth compound, wherein the non-porous
layer is adhered to the corrosion-resistant substrate and has 1) an
adhesion strength of .gtoreq.15 MPa, preferably .gtoreq.20 MPa or
.gtoreq.25 MPa or .gtoreq.30 MPa or .gtoreq.35 MPa or .gtoreq.40
MPa, 2) a thickness of .gtoreq.50 .mu.m, preferably .gtoreq.100
.mu.m or .gtoreq.150 .mu.m or .gtoreq.200 .mu.m or .gtoreq.250
.mu.m or .gtoreq.300 .mu.m; alternately a thickness in the range of
about 50 to about 500 .mu.m, preferably about 100 to about 400
.mu.m, more preferably about 150 to about 300 .mu.m, and 3) a
porosity of preferably .ltoreq.1% or .ltoreq.0.9% or .ltoreq.0.8%
or .ltoreq.0.7% or .ltoreq.0.6% or .ltoreq.0.5% or .ltoreq.0.4% or
.ltoreq.0.3% or .ltoreq.0.2% or .ltoreq.0.1%. In an example aspect,
layer 220 includes at least 15% by weight based on total weight of
layer of a rare earth compound. In example aspect, layer 220
includes an adhesion strength of at least 20 MPa; a porosity of at
most 1%; a microstructure substantially devoid of microcracks and
fissures and an average grain size of at least 100 nm and at most
100 .mu.m; and, a layer thickness of at least 50 .mu.m. In another
example aspect, the grain size is at least 300 nm and at most 30
.mu.m.
[0127] In an example aspect, lid 225 of the assembly includes layer
220, wherein the rare earth compound is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds and combinations of two or more
thereof. In another example aspect, the assembly includes the
corrosion-resistant ceramic insulating substrate 210, wherein the
substrate is selected from the group consisting of aluminum oxide,
aluminum nitride, silicon nitride, silicate-based materials and
mixtures of two or more thereof.
[0128] Another embodiment of the assembly further comprises an
interposing layer embedded in the substrate, or an interposing
layer between and adhered to both the corrosion-resistant substrate
and the non-porous layer. In an example aspect, the interposing
layer may serve one or more functions, for example, to promote
adhesion between the non-porous layer and the substrate, to prevent
an adverse reaction between the non-porous layer and the substrate,
and/or to provide some electrical function for the assembly. In
other example aspects, for applications involving very high
electric fields as required for particular lids, high electrical
resistivity is desirable to prevent losses affecting processing,
and therefore, an interposing layer such as ytterbium oxide
(Yb.sub.2O.sub.3) can be beneficial.
[0129] In an example aspect, the interposing layer is selected from
the group consisting of ytterbium oxide (Yb.sub.2O.sub.3),
MoSi.sub.2, radio-frequency (RF) conducting materials and mixtures
of two or more thereof. Preferably the corrosion-resistant lid of
the assembly is substantially transparent to radio-frequency (RF)
energy. The assembly, including the corrosion-resistant lid, is
preferably resistant to the plasma etching treatment employed in
semiconductor processing. Thus, the corrosion-resistant substrate
and the corrosion-resistant non-porous layer of corrosion-resistant
lid of the assembly are resistant to the plasma etching treatment
employed in semiconductor processing.
[0130] Another aspect of the invention is directed to a high
temperature corrosion-resistant wafer heater. FIG. 3 illustrates a
cross-sectional schematic view of wafer heater apparatus 300 as in
an example aspect. The wafer (not shown) sits on the outermost
layer (320) of insulating ceramic disk 310 having heating elements
340 embedded therein and also, optionally, metal RF shield 360. In
an example aspect insulating ceramic 310, from which these heaters
are made, is aluminum nitride. In other example aspects, alumina or
silicon nitride are useful as ceramic insulating substrate 310.
During operation, the heater is sometimes cleaned with
fluorine-containing gas. If the temperature of the heater exceeds
about 500.degree. C., then the heater itself may be attacked by the
fluorine thus making a corrosion-resistant protective layer
included onto the `hot` parts necessary. In an example aspect,
insulating ceramic 310 includes corrosion-resistant non-porous
layer 320 and optional interposing layer 330 therebetween.
Corrosion-resistant non-porous layer 320 includes an outer surface
for holding the wafer (not shown). Of particular importance is that
the region of the rare earth compound containing layer directly
under the wafer, in other words corrosion-resistant non-porous
layer 320, be dense. Otherwise particles from the heater would tend
to be shed onto the underside of the wafer. These shed particles
could migrate to the top side of the wafer in a subsequent step,
which would in turn result in defects in the patterns on the wafer.
The sides, bottom and coverage on the stalk or supporting disk 380
of the wafer heater are less critical, as there is no direct path
for particles to migrate to the wafer. A plasma spray coating
suffices to prevent against contamination for these other
regions.
[0131] FIG. 4 illustrates a chemical vapor deposition reactor
assembly including a wafer heater according to an example aspect of
the invention. Chemical vapor deposition (CVD) reactor assembly 400
includes showerhead 410 and heater 440. Reactive gases flow through
showerhead 410, which is protected by corrosion-resistant
non-porous layer 420, onto wafer 450, where a deposit is formed.
The temperature of the wafer is maintained and kept uniform by
heater 440, which may also have a non-porous corrosion-resistant
layer on it (as shown in FIG. 3) to protect it during cleaning.
Showerhead 410 may further include interposing or embedded layers,
such as an electrode, within to assist the generation of a plasma
to promote chemical reactions.
[0132] In an example aspect, assembly 400 is configured for use in
fabricating semiconductor chips. Assembly 400 includes
corrosion-resistant components (i) wafer heater 440, shown in FIG.
3 as wafer heater 300 in more detail), and/or (ii) showerhead 410.
In an example aspect, the deposition reactor is configured for
in-situ cleaning with halogen gases and a corrosion-resistant
component. Each corrosion-resistant component includes a ceramic
insulating substrate; and, a corrosion-resistant non-porous layer
of a composition comprising at least 15% by weight of a rare earth
compound based on total weight of layer. In an example aspect, the
rare earth compound is a trivalent oxide. In another example
aspect, the rare earth compound is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds and combinations of two or more
thereof. In an example aspect, the rare earth compound is yttrium
oxide (Y.sub.2O.sub.3). In an example aspect, the ceramic
insulating substrate is selected from the group consisting of
aluminum oxide, aluminum nitride, silicon nitride, silicate-based
materials, and mixtures of two or more thereof. In an example
aspect the corrosion-resistant component further includes at least
interposing layer between the substrate and the corrosion-resistant
non-porous layer. In an example aspect, the interposing layer is
selected from the group consisting of ytterbium oxide
(Yb.sub.2O.sub.3), MoSi.sub.2, radio-frequency (RF) conducting
materials and mixtures of two or more thereof. In an example
aspect, the substrate further includes at least one additional
interposing conductive layer embedded therein, the conductive layer
having a sheet resistivity of at most 10 Megaohm-cm, which may also
be written as 10 megohm-cm interchangeably herein.
[0133] In an example aspect, an assembly configured for use in
fabricating semiconductor chips, the assembly comprising a reactor
and a corrosion-resistant component. The corrosion-resistant
component includes a ceramic insulating substrate and a
corrosion-resistant non-porous layer associated with the ceramic
insulating substrate. In an example aspect, the corrosion-resistant
non-porous layer has a composition comprising at least 15% by
weight of a rare earth compound based on total weight of the
corrosion-resistant non-porous layer. In an example aspect, the
corrosion-resistant non-porous layer is characterized by a
microstructure substantially devoid of microcracks and fissures,
and having: a thickness of at least 50 .mu.m; a porosity of at most
1%; and, an average grain size of at least 100 nm and at most 100
.mu.m.
[0134] In an example aspect, the ceramic insulating substrate of
the assembly is selected from the group consisting of aluminum
oxide, aluminum nitride, silicon nitride, silicate-based materials
and mixtures of two or more thereof. In an example aspect, the rare
earth compound of the assembly is selected from the group
consisting of yttrium oxide (Y.sub.2O.sub.3), yttrium silicates,
yttrium fluorides, yttrium oxyfluorides, yttrium aluminates,
nitrides, complex nitride compounds, and combinations of two or
more thereof. In an example aspect, the corrosion-resistant
non-porous layer of the assembly is adhered to the ceramic
insulating substrate and has an adhesion strength of at least 20
MPa. In another example aspect, the corrosion-resistant non-porous
layer has a thickness of at least 100 .mu.m; a porosity of at most
0.5%; an adhesion strength of at least 30 MPa; and, an average
grain size of at least about 300 nm and at most about 30 .mu.m.
[0135] In an example aspect, the assembly further comprises at
least one interposing layer embedded in the ceramic insulating
substrate, or layered between the ceramic insulating substrate and
the corrosion-resistant non-porous layer. In an example aspect, the
at least one interposing layer is selected from the group
consisting of rare earth oxides, rare earth silicates, rare earth
aluminates, and mixtures of two or more thereof. In an example
aspect, the at least one interposing layer is ytterbium oxide
(Yb.sub.2O.sub.3). In an example aspect, the at least one
interposing layer comprises conducting materials that have a good
coefficient of thermal expansion match with the ceramic insulating
substrate and the corrosion-resistant non-porous layer. Thermal
expansion mismatches can be considered close if the difference in
thermal expansion coefficients is at most 4.times.10.sup.-6/K
relative to the coefficients for the ceramic insulating substrate
and the corrosion-resistant non-porous layer. In an example aspect,
the at least one interposing layer is chosen to be a material
having a thermal expansion coefficient difference of at most at
most 4.times.10.sup.-6/K relative to the coefficients for the
ceramic insulating substrate and the corrosion-resistant non-porous
layer. In an example aspect, the at least one interposing layer
further comprises insulating materials. In an example aspect, the
at least one interposing layer is selected from the group
consisting of ytterbium oxide (Yb.sub.2O.sub.3), molybdenum (Mo),
tungsten (W), molybdenum disilicide (MoSi.sub.2), tungsten carbide
(WC), tungsten disilicide (WSi.sub.2), and mixtures of two or more
thereof.
[0136] In an example aspect, the reactor is a plasma etch reactor
configured for plasma etching and the corrosion-resistant component
is a lid configured for releasable engagement with the plasma etch
reactor; and, wherein the lid has a loss tangent of less than
1.times.10.sup.-4 and is substantially transparent to
radio-frequency (RF) energy. In an example aspect, the reactor is a
deposition reactor configured for in-situ cleaning with halogen
gases and the corrosion-resistant component is a heater. In an
example aspect, the ceramic insulating substrate further includes
at least one interposing conductive layer embedded therein, the
conductive layer having a sheet resistivity of at most 10
Megaohm-cm. In another example aspect, the reactor is a deposition
reactor configured for in-situ cleaning with halogen gases and the
corrosion-resistant component is a showerhead.
[0137] Another aspect is directed to a method for preparing a
corrosion-resistant component for use with a reactor. The method
includes the steps as follows: a) laying up a thinner layer of a
sinterable powder composition comprising at least 15% by weight
based on total weight of the thinner layer of a rare earth
compound, and a thicker layer of sinterable substrate material to
form a pre-laminate (also referred to herein as `green laminate`);
and, b) heat treating the pre-laminate to form a
corrosion-resistant laminate. The terms "thinner" versus "thicker"
indicate that the thinner powder layer is less than 50% of the
thicker powder layer in the pressing direction. Heat treating is
selected from the group consisting of hot pressing and hot
isostatic pressing.
[0138] In an example aspect of the method, the sinterable substrate
material is selected from the group consisting of aluminum oxide,
aluminum nitride, silicon nitride, silicate-based materials, and
mixtures of two or more thereof. In an example aspect of the
method, the rare earth compound is a tri-valent rare earth oxide.
In an example aspect of the method, the rare earth compound is
selected from the group consisting of yttrium oxide
(Y.sub.2O.sub.3), yttrium silicates, yttrium fluorides, yttrium
oxyfluorides, yttrium aluminates, nitrides, complex nitride
compounds and combinations of two or more thereof. In an example
aspect of the method, the amount of rare earth compound is about 15
to 100 wt %, or about 20 to about 90 wt %, or about 25 to about 80
wt %. In an example aspect, the rare earth compound is
Y.sub.3Si.sub.3O.sub.10F. In an example aspect of the method, the
sinterable substrate material is aluminum oxide and the rare earth
compound is a trivalent rare earth oxide. In another example aspect
of the method, the sinterable substrate material is aluminum
nitride and the corrosion-resistant non-porous layer is a rare
earth silicate. In an example aspect of the method, the
corrosion-resistant component is a lid configured for releasable
engagement with a plasma etch reactor. In an example aspect of the
method, the lid has a loss tangent of less than 1.times.10.sup.-3.
In another example aspect of the method, the lid has a loss tangent
of less than 1.times.10.sup.-4. In an example aspect of the method,
the corrosion-resistant component is substantially transparent to
radio-frequency (RF) energy.
[0139] In an example aspect the method further comprises laying up
at least one additional sinterable powder composition layer
interposed between the rare earth compound thinner layer and the
substrate material thicker layer, prior to heat treatment. In
another example aspect of the method, the at least one additional
sinterable powder composition comprises a compound or metal
selected from the group consisting of ytterbium oxide
(Yb.sub.2O.sub.3), molybdenum (Mo), tungsten (W), niobium (Nb), and
compounds like molybdenum disilicide (MoSi.sub.2), tungsten carbide
(WC), tungsten disilicide (WSi.sub.2), titanium carbide (TiC),
titanium nitride (TiN), and other such conducting materials and
compounds that show metallic behavior and have a good coefficient
of thermal expansion match to the ceramic insulating substrate and
the corrosion-resistant non-porous layer, and mixtures of two or
more thereof. In an example aspect of the method, the at least one
additional sinterable powder composition is ytterbium oxide
(Yb.sub.2O.sub.3). In an example aspect, the method includes at
least one additional sinterable powder composition comprises
conducting materials. In an example aspect, the method includes at
least one additional sinterable powder composition comprises
conducting metals. In an example aspect, the method includes the at
least one additional sinterable powder composition further
comprises insulating materials. In another example aspect, the
method includes the at least one additional sinterable powder
composition further comprises an insulating material selected from
the group consisting of alumina, aluminum nitride, silicon nitride,
silicates, and mixtures of two or more thereof.
[0140] In an example aspect of the method, the semiconductor
processing reactor is a deposition reactor configured for in-situ
cleaning with halogen gases and the corrosion-resistant component
is a heater. In an example aspect of the method, the sinterable
substrate material further includes at least one interposing
conductive layer embedded therein, the conductive layer having a
sheet resistivity of at most 10 Megaohm-cm. In another example
aspect of the method, the semiconductor processing reactor is a
deposition reactor configured for in-situ cleaning with halogen
gases and the corrosion-resistant component is a showerhead.
EXAMPLES
[0141] For all examples, and in view of the need to minimize
contamination, a total concentration of undesirable elements in raw
materials used is at most 1 at %.
Example 1
[0142] Two disks (S1 and S12) made from an alumina-yttria laminate
were manufactured as follows. High purity chemically precipitated
yttrium oxide powder from AMR Corp. was attrition milled in water
to particle size d90<1 .mu.m. The slurry was then freeze dried
and sieved through a 150 .mu.m mesh.
[0143] Spray dried alumina powder of approximate composition 0.25
wt % SiO.sub.2, 0.05 wt % Na.sub.2O, 0.12 wt % MgO, 0.12 wt % CaO,
balance Al.sub.2O.sub.3 was heated in air at 800.degree. C. for 8
hours to remove binder from the spray dried powder. This powder is
referred to as CoorsTek 99512.
[0144] The alumina powder was cold pressed in a 6-inch diameter die
to a pressure of 440 psi and a total thickness of about 1 inch. A
layer of the yttria powder described above was then added on top of
the alumina and cold pressed to 440 psi again. The yttria layer was
about 2000 .mu.m thick at this point.
[0145] For the second laminate (S12), the process was repeated
except that a layer of ytterbium oxide (Yb.sub.2O.sub.3) powder
about 1000 .mu.m was interposed between the yttria layer and the
alumina layer.
[0146] The cold pressed laminate was transferred to a hot press
mold assembly, consisting of the stack arrangement depicted below
in Table 1.
TABLE-US-00001 TABLE 1 Stack arrangement for Example 1 Hot
Pressing. TOP 1-inch Graphite Spacer 1 Part 1-inch Graphite Spacer
3-inch Graphite Spacer BOTTOM
[0147] All spacers and parts were 6 inches in diameter. The Die
Barrel was 7 inches inside diameter (ID) and 15 inches outside
diameter (OD). The assembly was hot pressed according to the
temperature schedule shown in Table 2.
TABLE-US-00002 TABLE 2 Temperature Cycle during Hot Pressing.
Temperature, .degree. C. Time Ramp Setpoint, Soak (min) (.degree.
C./min) .degree. C. (min) Atmos. 0.0 20 1 Ar 1.0 5 1050 Ar 207.0
1050 10 Ar 217.0 5 1400 Ar 287.0 1400 60 Ar 347.0 3 1550 Ar 397.0
1550 60 Ar 457.0 5 1050 Ar 557.0 1050 10 Ar 567.0 5 300 Ar 717.0 5
20 Ar 773.0 20 1 Ar Ar = under argon atmosphere
[0148] Pressure was applied according to the cycle shown in Table
3.
TABLE-US-00003 TABLE 3 Pressure Cycle during Hot Pressing. Time
Pressure Ramp Soak total segment Psi (min) (min) min h m 6000 0 0 0
0 6000 287 287 4 47 7500 60 347 1 0 7500 102 449 1 42 6000 105 554
1 45 6000 208 762 3 28
[0149] Gray dense yttria-alumina laminates emerged from the hot
press operation. The grain size of the alumina as measured by the
ASTM-E112 method was 1.7 .mu.m. The carbon content was 640 ppm. The
loss tangent of Si measured at 5 GHz was 9.1.times.10.sup.-5.
Porosity was measured by image analysis of a polished section,
polished according to the following scheme (polishing supplies
provided by Struers, Inc.): [0150] 60 .mu.m diamond: as needed to
flatten the surface [0151] 15 .mu.m diamond, fixed abrasive pad: 2
min [0152] 9 .mu.m diamond, Largo (plastic) pad: 8 min [0153] 3
.mu.m diamond, DAC (nylon) pad: 6 min [0154] 1 .mu.m diamond,
napped cloth: 3 min.
[0155] The porosity of S1 and S12 were found to be 0.24% and 0.72%
respectively. The corrosion-resistant non-porous yttria layer was
observed to substantially have no microcracks or fissures.
Measuring from the sections, S1 and S12 had yttria layer thickness
of 910 .mu.m and 940 .mu.m respectively. The ytterbium oxide layer
thickness measured from the section was 520 .mu.m. Adhesion
strength as measured by a variant of ASTM C633 was found to be 30
MPa. As measured herein, adhesion strength is the force required to
cause failure when tension is applied between the outermost layer
and the substrate, irrespective of the presence or absence of
interposing layers or of the location of the failure, provided that
the failure is not confined exclusively to the substrate. The
outermost layer being adhered to the substrate may include
instances wherein at least one interposing layer is included and/or
a reaction layer inherently resulting from sintering exists between
the outermost layer and the substrate. For sample S1, a reaction
layer having composition Y.sub.3Al.sub.5O.sub.12 between the yttria
layer and the alumina substrate was present. Darkness L* of the
sample, measured on the yttria side with a Hunterlab MiniScan XE
colorimeter using the CIE L*a*b* color scale, was 53.9.
Example 2
[0156] Two yttria-aluminate laminates were cold pressed as
described for sample S1 in Example 1, except that one laminate (S4)
used Grade APA alumina powder from Sasol and the other laminate
(S5) used Grade AHPA alumina powder also from Sasol. The
cold-pressed disks were hot pressed with the same stackup as shown
in Table 4.
TABLE-US-00004 TABLE 4 Stack arrangement for Example 2 Hot
Pressing. TOP 1-inch Graphite Spacer 1 Part 1-inch Graphite Spacer
3-inch Graphite Spacer 1 Part 1-inch Graphite Spacer 3-inch
Graphite Spacer BOTTOM
[0157] The temperature and pressure cycles are shown in Tables 5
and 6.
TABLE-US-00005 TABLE 5 Temperature Cycle during Example 2 Hot
Pressing. Temperature, .degree. C. Time Ramp Setpoint, Soak (min)
(/min) .degree. C. (min) Atmos. 0.0 20 1 Ar 1.0 5 1050 Ar 207.0
1050 10 Ar 217.0 5 1200 Ar 247.0 1200 60 Ar 307.0 3 1400 Ar 373.7
1400 60 Ar 433.7 5 1050 Ar 503.7 1050 10 Ar 513.7 5 300 Ar 663.7 5
20 Ar 719.7 20 1 Ar Ar = under argon atmosphere
TABLE-US-00006 TABLE 6 Pressure Cycle during Example 2 Hot
Pressing. Time Pressure Ramp Soak total segment Psi (min) (min) min
h m 6000 0 0 0 0 6000 247 247 4 7 7500 60 307 1 0 7500 127 434 2 7
6000 80 514 1 20 6000 208 722 3 28
[0158] The grain sizes of the alumina as measured by the ASTM-E112
method were 0.76 .mu.m (S4) and 0.92 .mu.m (S5). The grain size of
the yttria measured in the same way was found to be 0.4 .mu.m. The
loss tangent of S4 at 5 GHz was found to be 11.times.10.sup.-5, and
that of S5 to be 15.7.times.10.sup.-5.
[0159] The porosity of both samples was measured by the method
described in Example 1. S4 had a porosity of 0.50% and S5 of 0.69%.
Substantially no microcracks or fissures were observed in the
corrosion-resistant non-porous yttria layer. Adhesion strength as
measured by ASTM C633 was found to be 20 MPa for S4 and 26 MPa for
S5. As with sample S1, a reaction layer between the yttria layer
and alumina substrate was present. Darkness L* of the sample,
measured on the yttria side with a Hunterlab MiniScan XE
colorimeter using the CIE L*a*b* color scale, was 49.7 for S4 and
66.1 for S5.
Example 3
[0160] Two yttria-alumina laminates were cold pressed as described
in Example 2. One laminate (S6) used AHPA alumina powder from
Sasol, and the other laminate (S7) used Baikowski TCPLS DBM alumina
powder from Baikowski-Malakoff. Each laminate was placed between
sheets of Mo foil.
[0161] The cold-pressed disks were hot pressed with the same stack
configuration as in Example 2. The temperature and pressure cycles
are shown in Tables 7 and 8.
TABLE-US-00007 TABLE 7 Temperature Cycle during Example 3 Hot
Pressing. Temperature, .degree. C. Time Ramp Setpoint, Soak (min)
(/min) .degree. C. (min) Atmos. 0.0 20 1 Ar 1.0 5 1050 Ar 207.0
1050 10 Ar 217.0 3 1200 Ar 267.0 1200 1 Ar 268.0 3 1400 Ar 334.7
1400 60 Ar 394.7 5 1050 Ar 464.7 1050 10 Ar 474.7 5 300 Ar 624.7 5
20 Ar 680.7 20 1 Ar Ar = under argon atmosphere
TABLE-US-00008 TABLE 8 Pressure cycle during Example 3 Hot
Pressing. Time Pressure Ramp Soak total segment Psi (min) (min) min
h m 6000 0 0 0 0 6000 217 217 3 37 7500 30 247 0 30 7500 148 395 2
28 6000 80 475 1 20 6000 208 683 3 28
[0162] The loss tangent of sample S6 was measured to be
4.times.10.sup.-5. L* was found to be 75.4 for S6 and 75.9 for S7.
Adhesion strength for S6 was 24 MPa and 35 MPa for S7.
Example 4
[0163] Two yttria-alumina laminates were cold pressed as described
for Sample S7 in Example 3. One laminate (S8) used AHPA alumina
powder from Sasol with which about 0.5% AlF.sub.3 had been dry
mixed, and the other laminate (S9) used Baikowski SA-80 alumina
powder from Baikowski-Malakoff (without AlF.sub.3 additions). Each
laminate was placed between sheets of molybdenum (Mo) foil.
[0164] Fluoride was added to S8 as a densification aid. The
cold-pressed disks were hot pressed with the same stackup as in
Example 2. The temperature cycle is shown in Table 9. The pressure
cycle is same as for Table 6, previously shown.
TABLE-US-00009 TABLE 9 Temperature cycle for Example 4 Hot
Pressing. Temperature, .degree. C. Time Ramp Setpoint, Soak (min)
(/min) .degree. C. (min) Atmos. 0.0 20 1 Ar 1.0 5 1050 Ar 207.0
1050 10 Ar 217.0 5 1200 Ar 247.0 1200 60 Ar 307.0 3 1400 Ar 373.7
1400 60 Ar 433.7 5 1050 Ar 503.7 1050 10 Ar 513.7 5 300 Ar 663.7 5
20 Ar 719.7 20 1 Ar Ar = under argon atmosphere
[0165] The laminate made from the AHPA powder including AlF.sub.3
additions was cracked in several places on removal and a porous
interface between the yttria layer and the alumina layer was
observed. The loss tangent of this sample (S8) was 2'10.sup.-5. The
loss tangent of S9 was 4.6.times.10.sup.-5. L* was found to be 48.6
for S8 and 76.0 for S9. Adhesion strength for S8 was less than 5
MPa and was 39 MPa for S9.
Example 5
[0166] Two yttria-alumina laminates were cold pressed as described
for sample S9 in Example 4, except that a layer of ytterbium oxide
(Yb.sub.2O.sub.3) powder about 0.04'' was interposed between the
yttria layer and the alumina layer. Both laminates used the
CoorsTek 99512 powder described in Example 1. One laminate (S11)
had one layer of 0.004'' Mo foil placed on one side, while the
other one (S10) did not.
[0167] The cold-pressed disks were hot pressed with the same
stackup as in Example 2. The pressure and temperature cycles are
the same as for example 4.
[0168] The loss tangent of S10 was found to be 15.times.10.sup.-5,
and its porosity was measured to be 1%. Substantially no
microcracks or fissures were observed in the corrosion-resistant
non-porous yttria layer. The as-hot-pressed layer thickness of
Y.sub.2O.sub.3 was 920 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 530 .mu.m after hot pressing. L* was
found to be 49.7 for S10. Adhesion strength for S10 was 28 MPa.
[0169] For S11, the as-hot-pressed layer thickness of
Y.sub.2O.sub.3 was 700 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 450 .mu.m after hot pressing.
Example 6
[0170] One yttria-alumina laminate (S43) was cold pressed as
described in Example 5, except that the yttria and ytterbia powders
were supplied by PIDC. The laminate used the APA powder from Sasol.
Mo foil was placed on both sides of the laminate.
[0171] The cold-pressed disk was hot pressed with the same stackup
as in Table 4 for Example 2. The temperature and pressure cycles
are shown in Tables 10 and 11.
TABLE-US-00010 TABLE 10 Temperature Cycle for Example 6 Hot
Pressing. Temperature, .degree. C. Time Ramp Setpoint, Soak (min)
(/min) .degree. C. (min) Atmos. 0.0 20 1 Vac 1.0 5 1050 Vac 207.0
1050 10 Vac 217.0 3 1200 Vac 267.0 1200 1 Vac 268.0 3 1550 Vac
384.7 1550 60 Vac 444.7 5 1050 Vac 544.7 1050 10 Vac 554.7 5 300
Vac 704.7 5 20 Vac 760.7 20 1 Vac
TABLE-US-00011 TABLE 11 Pressure Cycle for Example 6 Hot Pressing.
Time Pressure Ramp Soak total segment Psi (min) (min) min h m 0 0 0
0 0 217 217 3 37 2000 30 247 0 30 2000 198 445 3 18 0 110 555 1 50
0 151 706 2
[0172] The as-hot-pressed layer thickness of Y.sub.2O.sub.3 for S43
was 2950 .mu.m and the thickness of the Yb.sub.2O.sub.3 layer was
525 .mu.m after hot pressing.
Example 7
[0173] One yttria-alumina laminate (S50) was cold pressed as
described in Example 6. The laminate used the APA powder from
Sasol. Mo foil was placed on both sides of the laminate. The yttria
powder was mixed with 1 wt % ZrO.sub.2 before use.
[0174] The cold-pressed disk was hot pressed with the same stackup
as in Table 4 for Example 2. The pressure and temperature cycles
are the same as for Example 6. The loss tangent of S50 was found to
be 2.39'10.sup.-5. The as-hot-pressed layer thickness of
Y.sub.2O.sub.3 was 720 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 350 .mu.m after hot pressing. The grain
size of the yttrium oxide layer was estimated to be about
2.mu.m.
Example 8
[0175] Two yttria-alumina laminates were cold pressed as described
in Example 7. One laminate (S54) used the APA powder by Sasol,
along with PIDC yttria and a 40 .mu.m thick ceramic tape of
ytterbia, with the ytterbia powder also coming from PIDC. The
second laminate (S55) used HPA alumina from Orbite Technologies,
along with PIDC yttria and ytterbia. Both laminates had Mo foil on
both faces.
[0176] The cold-pressed disks were hot pressed with the same
stackup as in Table 4 for Example 2. The pressure and temperature
cycles are the same as for Example 6. The loss tangent of S54 was
found to be 3.93.times.10.sup.-5. The as-hot-pressed layer
thickness of Y.sub.2O.sub.3 was 985 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 40 .mu.m after hot pressing. For S55, the
loss tangent was found to be 2.06.times.10.sup.-5. The
as-hot-pressed layer thickness of Y.sub.2O.sub.3 was 1000 .mu.m and
the thickness of the Yb.sub.2O.sub.3 layer was 315 .mu.m after hot
pressing. The grain size of the yttrium oxide layers for S54 and
S55 were determined to be about 5 to 20 .mu.m.
Example 9
[0177] Two yttria-alumina laminates were cold pressed as described
in Example 8. One laminate (S57) used the APA powder by Sasol,
along with PIDC yttria mixed with 3 vol % yttrium oxyfluoride (YOF)
and PIDC ytterbia. The second laminate (S58) APA powder by Sasol,
PIDC ytterbia, and PIDC yttria mixed with 3 vol %
Y.sub.2Si.sub.2O.sub.7. Both laminates had Mo foil on both
faces.
[0178] The cold-pressed disks were hot pressed with the same
stackup as in Table 4 for Example 2. The pressure and temperature
cycles are the same as for Example 6. The loss tangent of S57 was
found to be 4.50.times.10.sup.-5. The as-hot-pressed layer
thickness of Y.sub.2O.sub.3 was 1085 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 380 .mu.m after hot pressing. The grain
size of the yttrium oxide layer for S57 was determined to be about
50 .mu.m. For S58, the loss tangent was found to be
7.73.times.10.sup.-5. The as-hot-pressed layer thickness of
Y.sub.2O.sub.3 was 980 .mu.m and the thickness of the
Yb.sub.2O.sub.3 layer was 425 .mu.m after hot pressing. The grain
size of the yttrium oxide layer for S58 was determined to be about
5 to 10 .mu.m.
Example 10
[0179] One laminate (S49) was cold pressed as described in Example
6. The laminate used the APA powder from Sasol as the alumina base
and a blend of 77 wt % yttria, 15 wt % zirconia, and 8 wt % alumina
as the top layer. Mo foil was placed on both sides of the
laminate.
[0180] The cold-pressed disk was hot pressed with the same stackup
as in Table 4 for Example 2. The pressure and temperature cycles
are the same as for Example 6. The loss tangent of S49 was found to
be 13.3.times.10.sup.-5. The as-hot-pressed layer thickness of
blended layer was 1215 .mu.m. Adhesion of the laminate was found to
be 32 MPa. The average grain size of the yttria-rich grains of the
non-porous layer was estimated to be about 2 .mu.m. At least one
second phase, namely alumina-rich grains of the composition
Y.sub.4Al.sub.2O.sub.9, was observed in the microstructure and this
second phase is believed to contribute to increased strength of the
layer.
[0181] A summary of properties for Examples 1 through 10 is
included in Table 12.
Listing of Elements
[0182] 100 corrosion-resistant component [0183] 110 ceramic
insulating substrate [0184] 120 corrosion-resistant non-porous
layer [0185] 130 interposing layer [0186] 150 corrosion-resistant
non-porous layer [0187] t1 thickness of layer 120 [0188] t2
thickness of layer 130 [0189] 200 plasma etch reactor assembly
[0190] 210 ceramic insulating substrate [0191] 220
corrosion-resistant non-porous layer [0192] 225 lid [0193] 240
induction coil [0194] 250 reactor [0195] 300 heater apparatus
[0196] 320 corrosion-resistant non-porous layer [0197] 330
interposing layer [0198] 330 insulating ceramic [0199] 340 heating
element(s) [0200] 360 radio-frequency (RF) shield [0201] 380
supporting disk [0202] 400 CVD reactor assembly [0203] 410
showerhead [0204] 420 corrosion-resistant non-porous layer [0205]
440 heater [0206] 450 wafer being processed
TABLE-US-00012 [0206] TABLE 12 Summary of Properties.
Y.sub.2O.sub.3 Yb.sub.2O.sub.3 Loss Grain Size Grain Size Sample
Thickness Thickness Porosity Tangent Adhesion Alumina Yttria Carbon
ID (.mu.m) (.mu.m) (%) (.times.10.sup.-5) L* (MPa) (.mu.m) (.mu.m)
(ppm) 1 908 -- 0.24 9.1 53.9 30 1.7 -- 640 4 799 -- 0.5 11 49.7 20
0.76 0.4 -- 5 626 -- 0.69 15.7 66.1 26 0.92 -- -- 6 -- -- -- 4 75.4
24 -- -- -- 7 -- -- -- 53.2 75.9 35 -- -- -- 8 -- -- -- 2.3 76.0
<5 -- -- -- 9 -- -- -- 4.6 48.6 38 -- -- -- 10 920 530 1 15 49.7
28 -- -- -- 11 704 447 0.66 -- -- -- -- -- -- 12 935 524 0.72 -- --
-- -- -- -- 43 2950 525 -- -- -- -- -- -- -- 49 1215 -- <1 13.3
-- 32 -- 2 -- (top layer) 50 720 350 -- 2.4 -- -- -- 2 -- 54 985 40
-- 3.9 -- -- -- 5-20 -- 55 1000 315 -- 2.1 -- -- -- 5-20 -- 57 1085
380 -- 4.5 -- -- -- 50 -- 58 980 425 -- 7.7 -- -- -- 5-10 --
Other Embodiments
[0207] A number of variations and modifications of the disclosure
can be used. It would be possible to provide for some features of
the disclosure without providing others.
[0208] The present disclosure, in various aspects, embodiments, and
configurations, includes components, methods, processes, systems
and/or apparatus substantially as depicted and described herein,
including various aspects, embodiments, configurations,
subcombinations, and subsets thereof. Those of skill in the art
will understand how to make and use the various aspects, aspects,
embodiments, and configurations, after understanding the present
disclosure. The present disclosure, in various aspects,
embodiments, and configurations, includes providing devices and
processes in the absence of items not depicted and/or described
herein or in various aspects, embodiments, and configurations
hereof, including in the absence of such items as may have been
used in previous devices or processes, for example, for improving
performance, achieving ease and/or reducing cost of
implementation.
[0209] The foregoing discussion of the disclosure has been
presented for purposes of illustration and description. The
foregoing is not intended to limit the disclosure to the form or
forms disclosed herein. In the foregoing Detailed Description for
example, various features of the disclosure are grouped together in
one or more, aspects, embodiments, and configurations for the
purpose of streamlining the disclosure. The features of the
aspects, embodiments, and configurations of the disclosure may be
combined in alternate aspects, embodiments, and configurations
other than those discussed above. This method of disclosure is not
to be interpreted as reflecting an intention that the claimed
disclosure requires more features than are expressly recited in
each claim. Rather, as the following claims reflect, inventive
aspects lie in less than all features of a single foregoing
disclosed aspects, embodiments, and configurations. Thus, the
following claims are hereby incorporated into this Detailed
Description, with each claim standing on its own as a separate
preferred embodiment of the disclosure.
[0210] Moreover, though the description of the disclosure has
included description of one or more aspects, embodiments, or
configurations and certain variations and modifications, other
variations, combinations, and modifications are within the scope of
the disclosure, for example, as may be within the skill and
knowledge of those in the art, after understanding the present
disclosure. It is intended to obtain rights which include
alternative aspects, embodiments, and configurations to the extent
permitted, including alternate, interchangeable and/or equivalent
structures, functions, ranges or steps to those claimed, whether or
not such alternate, interchangeable and/or equivalent structures,
functions, ranges or steps are disclosed herein, and without
intending to publicly dedicate any patentable subject matter.
[0211] From the above description, one skilled in the art can
easily ascertain the essential characteristics of the present
invention, and without departing from the spirit and scope thereof,
can make various changes and modifications of the invention to
adapt it to various usages and conditions. Thus, other embodiments
are also considered to be within the scope of the present
claims.
* * * * *