Ex Parte Kiehlbauch et al

Board of Patent Appeals and Interferences

Jun 13, 2012

11812902 (B.P.A.I. Jun. 13, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte MARK W. KIEHLBAUCH
and
JOHN E. DAUGHERTY
____________

Appeal 2011-006480
Application 11/812,902
Technology Center 1700
____________

Before PETER F. KRATZ, ROMULO H. DELMENDO, and
GEORGE C. BEST, Administrative Patent Judges.

DELMENDO, Administrative Patent Judge.

DECISION ON APPEAL
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Mark W. Kiehlbauch and John E. Daugherty, the Appellants,1 seek
our review under 35 U.S.C. § 134(a) of a final rejection of claims 21-25, 43,
44, and 47.2 We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM-IN-PART and REVERSE-IN-PART.

STATEMENT OF THE CASE
The invention relates to components made of quartz glass for plasma
processing apparatuses where plasma-exposed surfaces of the components
are finished to a different surface morphology relative to non-plasma-
exposed surfaces in order to provide reduced particle contamination.
Specification (“Spec.”), ¶¶ [0002], [0005]. Specifically, the Appellants
explain that the surface of quartz glass components that need to provide a
vacuum seal (e.g., O-ring seating surfaces) must have a finish that provides
suitable vacuum sealing performance, and that such “a desirable vacuum
seal surface finish can be significantly different from a desirable plasma-
exposed surface.” Id. at ¶ [0024]. The Appellants state that “[f]or example,
plasma-exposed surfaces can be mechanically polished to a lower Ra value
(i.e., a smoother finish), than non-plasma-exposed surfaces, for which
particulate removal during plasma processing is of less concern.” Id. at
¶ [0033]. According to the Appellants, “[t]he component can be a gas
injector, dielectric window, electrode, view port, edge ring, focus ring,
confinement ring, or the like, for a plasma reactor.” Id. at ¶ [0025].

1 The Appellants state that the real party in interest is “LAM RESEARCH
CORPORATION.” Appeal Brief filed December 22, 2010 (“App. Br.”) at
2.
2 App. Br. 2; Examiner’s Answer mailed January 24, 2011 (“Ans.”) at 2;
Final Office Action mailed September 29, 2010.
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Claim 21 on appeal is reproduced below:
21. A component for a plasma processing apparatus,
comprising:
at least one plasma-exposed quartz glass surface having a
first arithmetical surface roughness Ra; and
at least one vacuum sealing quartz glass surface having a
second arithmetical surface roughness Ra different from the first
arithmetical surface roughness Ra.

The Examiner rejected the claims under 35 U.S.C. § 103(a) as
follows:
I. Claims 21-23, 25, and 47 as unpatentable over
McMillin3 in view of Demaray,4 Inaki,5 Lorenz,6
and Wang;7
II. Claim 24 as unpatentable over McMillin in view of
Demaray, Inaki, Lorenz, Wang, and Kobayashi;8
and

3 U.S. Patent 6,013,155 issued January 11, 2000.
4 U.S. Patent Application Publication 2002/0187271 A1 published
December 12, 2002.
5 U.S. Patent Application Publication 2003/0190483 A1 published October
9, 2003, based on Application 10/343,470 with a PCT filing date of July 30,
2001.
6 U.S. Patent Application Publication 2003/0156963 A1 published August
21, 2003, based on Application 09/863,073 filed May 21, 2001.
7 U.S. Patent Application Publication 2004/0099285 A1 published May 27,
2004, based on Application 10/304,535 filed November 25, 2002.
8 U.S. Patent 6,245,147 B1 issued June 12, 2001.
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III. Claims 43 and 44 as unpatentable over McMillin
in view of Demaray, Inaki, Lorenz, Wang,
Hellmann,9 and Ruppert.10
Ans. 4-16.

DISCUSSION
The Appellants have argued various groups of claim(s) as follows: (1)
claims 21-23, 25, and 47; (2) claim 23; (3) claim 25; (4) claim 24; and (5)
claims 43 and 44. App. Br. 3-11. Regarding group (1), we select claim 21as
representative and confine our discussion to this selected claim. The other
claims within group (1) stand or fall with claim 21. See 37 C.F.R.
§ 41.37(c)(1)(vii).

Claim 21:
The Examiner found that McMillin describes a quartz dielectric
window disposed in a vacuum plasma processing apparatus, the dielectric
window inherently having a surface exposed to plasma and a different
vacuum sealing surface. Ans. 4. The Examiner acknowledged that
McMillin does not disclose that the plasma-exposed surface has a surface
roughness Ra that differs from that of the vacuum sealing surface. Id.
Nevertheless, the Examiner relied on the teachings of Demaray and Inaki to
conclude that the difference between the subject matter of claim 21 and

9 U.S. Patent 6,150,006 issued November 21, 2000.
10 U.S. Patent Application Publication 2002/0104332 A1 published August
8, 2002.
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McMillin would have been obvious to a person of ordinary skill in the art.
Id. at 4-8.
The Appellants contend that the Examiner failed to make out a prima
facie case obviousness because “[t]he vacuum required for McMillin’s
plasma processing chamber is orders of magnitude different than that for
Demaray’s physical vapor deposition chamber.” App. Br. 5. The
Appellants further argue:
Demaray does not relate to a dielectric window of quartz and
but for impermissible hindsight, one of ordinary skill in the art
would have had no apparent reason to use the surface roughness
of the ceramic insulator 133 in Demaray’s physical vapor
deposition chamber for the vacuum sealing surface of the
dielectric window 155 in McMillin’s plasma processing
chamber.
Id. Regarding Inaki, the Appellants urge that “Inaki does not disclose a
quartz component having a vacuum sealing surface nor does Inaki suggest
providing difference surface roughness on plasma exposed and vacuum
sealing surfaces.” Id. at 6.
Thus, the dispositive issue arising from these contentions is:
Did the Examiner articulate some reasoning with some rational
underpinning to support the conclusion that a person of ordinary skill in the
art would have been prompted to provide a surface roughness for McMillin’s
vacuum sealing surfaces that differs from the surface roughness of plasma-
exposed surfaces?
Finding no reversible error, we uphold the Examiner’s obviousness
conclusion. Our reasons follow.
It is undisputed that McMillin describes a component for a plasma
processing chamber in the form of a dielectric window made of quartz
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having a plasma-exposed surface and a vacuum sealing surface. App. Br. 5;
Ans. 4.
Although Demaray relates to insulating sealing structures in a
physical vapor deposition (e.g., plasma sputtering) apparatus, it teaches the
importance of polishing the surface of a main insulator (alumina or quartz)
to a finish (i.e., a surface roughness height value of about 16 μin [0.40 μm],
preferably 8 μin [0.20 μm] in the direction perpendicular to the seal)
necessary to make an adequate seal with a mating surface to provide a high
vacuum (at least 10-6 Torr). ¶¶ [0003]-[0007], [0037]-[0041], [0049]. Thus,
a person of ordinary skill in the art would have drawn a reasonable inference
from Demaray’s teachings that the surface roughness of the sealing surfaces
of a component in a vacuum sealed apparatus is a variable that affects the
degree of vacuum that can be achieved and maintained. Demaray’s reason
for polishing the vacuum sealing surfaces is the same or similar to that
disclosed by the Appellants. Spec. ¶ [0002].
Inaki teaches a quartz glass jig, which were known to be used as
window materials, that contacts plasma in a semiconductor processing
apparatus. ¶¶ [0001]-[0002]. According to Inaki, when the quartz glass jig
is subjected to mechanical processing so as to have a surface roughness Ra
of from 2 μm to 0.05 μm, while making a depth of microcracks 50 μm or
less, the jig “is free from the generation of abnormal etching and particles
and is low in contamination of a silicon wafer with impurities.” ¶¶ [0004],
[0008]-[0009]. Therefore, Inaki also discloses a relationship between the
surface roughness of the plasma-exposed surface and the efficacy of the
semiconductor processing apparatus.
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Given these teachings, we find no error in the Examiner’s conclusion
that a person of ordinary skill in the art would have “combine[d] the
teachings of McMillin and Demaray to yield predictable results such as
providing a desired sealing surface finish in the apparatus of McMillin to
maintain an adequate seal in their apparatus as taught by Demaray.” Ans.
21; see also Ans. 8-9. That is, a person of ordinary skill in the art would
have found it obvious to determine the workable or optimum surface
roughnesses for the vacuum sealing surfaces of McMillin’s dielectric
window, using the surface roughness disclosed in Demaray as a guide,
because it was known that the surface roughness of a mating surface affects
the degree of vacuum seal that can be achieved. In re Boesch, 617 F.2d 272,
276 (CCPA 1980) (“[D]iscovery of an optimum value of a result effective
variable in a known process is ordinarily within the skill of the art.”); In re
Aller, 220 F.2d 454, 456 (CCPA 1955) (“[W]here the general conditions of a
claim are disclosed in the prior art, it is not inventive to discover the
optimum or workable ranges by routine experimentation.”).
Similarly, it was known in the art, as evidenced by Inaki’s teachings
identified above, that the surface roughness of quartz window exposed to
plasma can affect the quality of the process. Hence, as pointed out by the
Examiner, Ans. 8, a person of ordinary skill in the art would have found it
obvious to determine by routine experimentation, using Inaki’s disclosure as
a guide, the surface roughnesses of the plasma-exposed surfaces of
McMillin’s dielectric window that would provide the most optimum results.
Because the surface roughnesses are adjusted for different reasons in
Demaray and Inaki, it would reasonably appear that a person of ordinary
skill in the art would have arrived at surface roughness values for the
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vacuum sealed surfaces and plasma-exposed surfaces of McMillin’s quartz
dielectric window that necessarily differ, thus arriving at a device
encompassed by claim 21. The Appellants have offered no persuasive
argument or evidence to the contrary.
We therefore uphold the Examiner’s rejection of claim 21.

Claim 23:
Claim 23, which depends from claim 21, recites in part: “wherein the
plasma-exposed quartz glass surface has . . . a ratio of actual surface
area/nominal surface area of about 1.1-4 or about 1.2-1.5.”
The Examiner found that Lorenz discloses a relationship between
surface texture and surface area and thus concluded that the claimed subject
matter would have been obvious to a person of ordinary skill in the art in
view of the cited references. Ans. 9.
The Appellants argue that fractured particles from mechanical
polishing are removed by etching and that the etched surface can be
characterized by the recited Ra and ratio of actual surface area/nominal
surface area. App. Br. 7-8. The Appellants further contend that Lorenz “has
nothing to do with polishing quartz glass or components of plasma
processing apparatus.” App. Br. 8.
Thus, the dispositive issues are:
Does claim 23 required an etched surface?
Does the mere fact that Lorenz’s disclosure is unrelated to polishing
quartz glass or components of plasma processing demonstrate reversible
error in the Examiner’s obviousness conclusion?
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We find no persuasive merit in the Appellants’ arguments. Claim 23
contains no limitation as to any etched surface. Regarding the relevance of
Lorenz, we find that Lorenz’s disclosure relates to powder metallurgy.
¶ [0026]. The Examiner, however, cited Lorenz to show the relationship
between surface roughness and the surface area. Ans. 9, 25. In particular,
Lorenz teaches that surface texture is related to the surface area and that
surface texturing gives rise to an actual surface area that exceeds nominal
surface area by approximately 25-500% of the nominal surface area.
¶ [0108]; Lorenz’s claim 69. We find that a person of ordinary skill in the
art, who is presumed to have ordinary common sense and technical
expertise, would have understood that concept to be applicable even for
quartz glass. Indeed, our finding is consistent with the Appellants’ own
disclosure that “[i]ncreasing the surface roughness increases the actual
surface area of a component.” Spec. ¶ [0037]. Under these circumstances, it
would reasonably appear that the claimed range of ratios of actual surface
area to nominal surface area, as broadly recited in claim 23, would
encompass or overlap McMillin’s ratio of actual surface area to nominal
surface area upon optimization of the surface roughness. The Appellants
have offered no persuasive argument or evidence to the contrary.
Therefore, we also uphold the Examiner’s rejection of claim 23.

Claim 25:
Claim 25 recites in relevant part (emphasis added):
the plasma-exposed quartz glass surface has at least one
of (i) an arithmetical mean roughness Ra of about 5-20
microinches, or about 12-20 microinches, (ii) a ratio of actual
surface area/nominal surface area of about 1.1-4, or about 1.2-
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1.5, and (iii) a characteristic feature length of about 2-30
microns, or about 5-20 microns; and
the vacuum sealing quartz glass surface has at least one
of (i) an arithmetical mean roughness Ra of about 10-20
microinches and 9ii) a characteristic feature length of about 5-
25 microns.
The Appellants rely on the same arguments made against claim 23.
App. Br. 8-9. Because claim 25 recites “at least one of,” our discussions
above with respect to claim 21 and 23 apply with equal force. We need not
discuss the “characteristic feature length” issue because it is unnecessary to
support a conclusion of obviousness as to claim 25.

Claim 24:
Claim 24 recites in relevant part: “wherein the plasma-exposed quartz
glass surface has a level of at least one metal selected from the group
consisting of Al, B, Ca, Cr, Cu, Fe, Li, Mg, Ni, K, Na, Ti and Zn of less than
about 1,000 x 1010 atoms/cm2, or less than about 100 x 1010 atoms/cm2, or
less than about 10 x 1010 atoms/cm2.”
The Examiner found that Kobayashi teaches the use of a quartz glass
body with low levels of Fe impurities to avoid its adsorption into silicon
wafer. Ans. 12. The Examiner thus concluded that a person of ordinary
skill in the art would have been prompted to use quartz glass with low Fe
impurities in the modified apparatus of McMillin in order to prevent the
deposition of contaminants on the semiconductor device. Id. at 13.
The Appellants contend that “Kobayashi fails to disclose the claimed
metal content on a plasma exposed quartz glass surface and thus fails to cure
the deficiencies of the remaining references.” App. Br. 10.
Thus, the dispositive issue is:
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Did the Examiner err in concluding that a person of ordinary skill in
the art would have combined the teachings of Kobayashi and the other
references to arrive at a component encompassed by claim 24?
We find ourselves in agreement with the Examiner’s factual findings
and conclusions. Ans. 12-13, 27-28. Therefore, we adopt them as our own.
The Appellants’ argument fails to demonstrate why the advantages of low Fe
level would not be applicable for plasma-exposed quartz glass.

Claims 43 and 44:
Claim 43 recites that the “plasma-exposed glass surface is a
mechanically polished and chemically etched surface having a ratio of actual
surface area/nominal surface area of about 1.1 to 4, or about 1.2 to 1.5.”
Claim 44 recites similar language but with respect to the vacuum sealing
glass surface.
The Examiner acknowledged that McMillin does not disclose
mechanical polishing and chemical etching but concluded that these
differences would have been obvious to a person of ordinary skill in the art
in view of Ruppert and Hellmann. Ans. 13-16. According to the Examiner,
“[i]t would [have been] obvious to a skilled artisan to chemically etch a
surface of dielectric window in the apparatus of McMillin, Demaray, Inaki,
Lorenz[,] and Wang as taught by Hellmann.” Id. at 15.
The Appellants argue, inter alia, that “Hellmann relates to quartz
glass components for CVD [chemical vapor deposition] wherein the surfaces
are rough enough to be suitable for adhesion of CVD coats deposited at high
temperatures” and that “Hellmann fails to provide a suggestion to use
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chemically etched quartz glass components in a plasma processing
chamber.” App. Br. at 11.
Thus, a dispositive issue is;
Did the Examiner articulate some reasoning with some rational
underpinning to support a conclusion that a person of ordinary skill in the art
would have combined McMillin and Hellmann in the manner claimed?
We agree with the Appellants on this issue. The Examiner relies on
Hellmann’s disclosure in the Abstract and column 4, lines 36-55 and 65-67.
Ans. 15. Hellmann’s Abstract, however, teaches a quartz glass component
particularly suitable for the adhesion of CVD layers. The Examiner has not
shown that adhesion of CVD layers would be desirable or even relevant for
McMillin’s dielectric window. Hellmann’s column 4, lines 36-55 and 65-67
is also of no help. That section of Hellman, like the Abstract, is silent
regarding any sort of dielectric window. Therefore, the Examiner stated
reasons in support of the obviousness conclusion is not supported by the
relied-upon evidence.

ORDER
The Examiner’s rejection of claims 21-25 and 47 is affirmed, but the
rejection of claims 43 and 44 is reversed.

No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1)(iv).
AFFIRMED-IN-PART

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