Ex Parte Cherian et al

Board of Patent Appeals and Interferences

Feb 6, 2012

11205428 (B.P.A.I. Feb. 6, 2012)

UNITED STATES PATENT AND TRADEMARK OFFICE
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O. Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
11/205,428 08/17/2005 Isaac K. Cherian 100251 3864
29050 7590 02/07/2012
STEVEN WESEMAN
ASSOCIATE GENERAL COUNSEL, I.P.
CABOT MICROELECTRONICS CORPORATION
870 NORTH COMMONS DRIVE
AURORA, IL 60504
EXAMINER
PARVINI, PEGAH
ART UNIT PAPER NUMBER
1731
MAIL DATE DELIVERY MODE
02/07/2012 PAPER
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte ISAAC K. CHERIAN and KEVIN J. MOEGGENBORG
____________

Appeal 2011-006443
Application 11/205,428
Technology Center 1700
____________

Before BRADLEY R. GARRIS, LINDA M. GAUDETTE, and JAMES C.
HOUSEL, Administrative Patent Judges.

HOUSEL, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134 from the Examiner's
decision finally rejecting claims 1-7, 12 and 27 under 35 U.S.C. § 103(a).
We have jurisdiction under 35 U.S.C. § 6(b).
We AFFIRM.
Appellants claim a chemical-mechanical polishing (hereinafter CMP)
system for polishing a substrate comprising a water-soluble silicate
compound, an oxidizing agent that oxidizes at least a part of a substrate,
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water, and a polishing pad, wherein the polishing system is substantially free
of abrasive particles and has a pH of about 11 to about 12, and wherein the
silicate compound is dissolved in the water of the polishing system. (Claim
1).
Representative claim 1, the sole independent claim on appeal, reads as
follows:
1. A chemical-mechanical polishing system for polishing a substrate
comprising:

(a) a water-soluble silicate compound in an amount sufficient to
provide about 0.5 wt.% to about 8 wt.% of SiO2,

(b) an oxidizing agent that oxidizes at least a part of a substrate,

(c) water, and

(d) a polishing pad,

wherein the polishing system is free of abrasive particles, wherein the
polishing system has a pH of about 11 to about 12, and wherein the water-
soluble silicate compound is dissolved in the water of the polishing system.

The references listed below are relied upon by the Examiner as
evidence of obviousness:
Farcnik 4,277,355 Jul. 07, 1981
Chopra 6,276,996 B1 Aug. 21, 2001
Sinha et al. 6,551,935 B1 Apr. 22, 2003
Chen et al. 2003/0189186 A1 Oct. 09, 2003
Moeggenborg 2003/0228762 A1 Dec. 11, 2003
Ma 2005/0026437 A1 Feb. 03, 2005

Under 35 U.S.C. § 103(a), the Examiner rejects:
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claims 1-7, and 27 as unpatentable over Moeggenborg in view of
Sinha and Ma, as evidenced by Farcnik;
claim 12 as unpatentable over the references applied against claim 1
and further in view of Chen;
claims 1-7, and 27 as unpatentable over the Moeggenborg in view of
Chopra and Ma, as evidenced by Farcnik; and
claim 12 as unpatentable over the references applied against claim 1
and further in view of Chen.

We will sustain the above rejections for the reasons expressed in the
Answer. The following comments are added for emphasis.

The Rejections based on Moeggenborg in view of either Sinha or
Chopra, and Ma, taken with Farcnik
Appellants do not separately argue any of the claims on appeal under
these rejections, but instead focus their arguments on the limitations of claim
1. (Br. 3-11). For purposes of this appeal, we select claim 1 to decide the
issues for these rejections. See 37 C.F.R. § 41.37(c)(1)(vii) (“When multiple
claims subject to the same ground of rejection are argued as a group by
appellant, the Board may select a single claim from the group of claims that
are argued together to decide the appeal with respect to the group of claims
as to the ground of rejection on the basis of the selected claim alone.”).
The Examiner found that Moeggenborg teaches a CMP system
comprising a polishing pad, any suitable corrosion inhibitor, hydrogen
peroxide as an oxidizing agent, and water, wherein the system is free of
abrasive particles and has a pH of about 12 or lower (Ans. 4, 9). In addition,
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the Examiner found the alternative secondary references to Sinha and
Chopra teach CMP systems including potassium silicate as a known
corrosion inhibitor.
We share the Examiner's conclusion that it would have been obvious
to substitute the recited corrosion inhibitor of Moeggenborg’s CMP system
with potassium silicate since potassium silicate is a known corrosion
inhibitor for use in CMP systems as taught by either Sinha or Chopra (Ans.
4, 9 and 10). Further, we find no error in the Examiner’s conclusion that the
amount of silicate used would provide a wt.% of SiO2 that substantially
overlaps the claimed range of “about 0.5 wt.% to about 8 wt.%” in view of
the teaching of Ma that the amount of corrosion inhibitor in abrasive free
CMP systems may be up to 5 wt.%. As noted by the Examiner, a 2.0 wt.%
of potassium silicate would provide about 0.78 wt.% of SiO2 in solution, and
falls within the claimed range (Ans. 5, 10). To reinforce the Examiner’s
obviousness conclusion, we note that the alternative secondary references to
Sinha and Chopra teach the use of a corrosion inhibitor up to 2.0 wt.%, and
provide a list of suitable corrosion inhibitors that include potassium silicate
and azole compounds, thus suggesting potassium silicate is a suitable
alternative to the azole corrosion inhibitor compounds as used in
Moeggenborg.
Farcnik was relied on by the Examiner as evidence of the typical
chemical formula for potassium silicate (i.e. K2SiO2) used to determine the
amount of silica provided by a particular amount of silicate (Ans. 5, 6, 11).
As the claims are broad with regard to the formula for the silicate and
include any known formula, and the Appellants do not argue this point, we
need not further address Farcnik.
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Appellants argue that a CMP system prepared from the combined
teachings of the applied prior art would not have resulted in a CMP system
within the claim. In particular, Appellants assert that a polishing system
prepared based on the applied prior art would not contain sufficient
potassium silicate dissolved in water to provide about 0.5-8 wt.% SiO2 and
would not have a pH within the range of about 11 to about 12 (Br. 7).
Appellants analyze each of the applied prior art references individually with
respect to these elements.
Appellants' argument is unpersuasive. Nonobviousness is not
established simply because no single reference teaches or suggests an
abrasive free CMP system with a pH of about 11 to about 12 comprising a
polishing pad, an oxidizing agent, water, and a sufficient amount of
potassium silicate dissolved in the water to provide 0.5 wt.% to about 8
wt.% SiO2. However, the combined teachings of the applied references
would have suggested the use of potassium silicate, in an amount that would
provide SiO2 within the claimed range, as the corrosion inhibitor in the CMP
system of Moeggenborg, wherein the pH fully encompasses the claimed
range, as fully explained by the Examiner (Ans. 6, 11, 15). In this regard,
we remind Appellants that the test for obviousness is what the combined
teachings of the applied references would have suggested to those with
ordinary skill in the art. See In re Keller, 642 F.2d 413, 425 (CCPA 1981).
Appellants argue that while Moeggenborg discloses that the CMP has
a pH in the range of about 6 to about 12, Moeggenborg does not disclose the
narrower claimed pH range of about 11 to about 12 (Br. 6). This argument
is unpersuasive. Moeggenborg’s pH range is broader than and fully
encompasses the narrower pH range. We conclude that a prima facie case of
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obviousness has been made out in this case. In re Peterson, 315 F.3d 1325,
1329 (Fed. Cir. 2003) (“In cases involving overlapping ranges, we and our
predecessor court have consistently held that even a slight overlap in range
establishes a prima facie case of obviousness.”). Selecting a narrow range
from within a somewhat broader range disclosed in a prior art reference is no
less obvious than identifying a range that simply overlaps a disclosed range.
Id. at 1329-30. In fact, when as here, the claimed range is completely
encompassed by the prior art, the conclusion is even more compelling than
in cases of mere overlap. Id.
Appellants further assert the Examiner failed to provide any credible
reason for the combination and that the prior art teaches away from the
claimed pH range (Br. 10), without specifically addressing the Examiner’s
findings concerning this limitation. As explained by the Examiner, the pH
ranges used by Sinha’s and Chopra’s CMP systems do not negate the
teaching of Moeggenborg to provide a pH of about 12 or lower. In teaching
that potassium silicate is a known corrosion inhibitor for use in CMP
systems (and an alternative to the azole compounds taught in Moeggenborg),
Sinha and Chopra do not teach away from using potassium silicate or any
other known corrosion inhibitor in the claimed pH range. The Examiner’s
conclusion of obviousness is consistent with the prior art references taken as
a whole.
We note that appellants may overcome a prima facie case of
obviousness by establishing that the claimed range is critical, or generally by
showing that the claimed range achieved unexpected results relative to the
prior art range (In re Geisler, 116 F.3d 1465, 1469-70 (Fed. Cir. 1997)). In
this regard, Appellants direct our attention to Specification Example 1 and
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the Moeggenborg Declaration under 37 C.F.R. § 1.132 as objective evidence
of unexpected results. In particular, Appellants indicate that Specification
Example 1 shows a trend of increasing tantalum removal rate as a function
of the amount of potassium silicate that demonstrates a critical limit occurs
at an amount more than 0.25 wt.% and less than 0.75 wt.% (Br. 8).
Appellants also assert that the Moeggenborg Declaration confirms that, at a
pH below about 11, polishing compositions cannot contain sufficient
potassium silicate in solution to provide about 0.5-8 wt.% SiO2 (Br. 7).
We have fully considered Example 1 and the Moeggenborg
Declaration in the totality of the record before us and conclude that
Appellants have not carried forward their burden of establishing that the
Examiner erred in concluding that the claimed invention would have been
obvious over the applied prior art. See In re Klosack, 455 F.2d 1077, 1080
(CCPA 1972) (noting that the burden of analyzing and explaining data to
support nonobviousness rests with the appellants). The Examiner found, and
we agree, that this evidence is not commensurate with, and does not evince
of a clear trend of unexpected results for, the full the scope of the claims
(Ans. 20-21). We note that while claim 1 recites that the silicate is
dissolved in the water of the polishing system and provides about 0.5-8 wt.
% SiO2, the claim does not require that 0.5-8 wt. % SiO2 is dissolved in
solution. Further we find no support in the Moeggenborg Declaration for
Appellants’ statement that, for pH levels below about 11, “no amount of
potassium silicate added to the polishing composition will provide sufficient
potassium silicate in solution equivalent to a level of SiO2 of about 0.5-8
wt.%” (Br. 9). On the contrary, paragraph 5 of the Declaration states that
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only one composition outside the claimed pH range exhibited settling, while
another composition also outside the claimed range did not.

In sum, taking into account Appellants’ evidence of unexpected
results, we determine that a preponderance of the evidence favors the
Examiner’s conclusion of obviousness as to appealed claims 1-7, and 27.

The Remaining Rejections Adding Chen
Dependent claim 12 adds the limitation that the CMP system of claim
1 further comprises about 1 ppm to about 50 ppm of calcium ion. In
addition to the argument and evidence discussed above, Appellants argue
that there is no credible reason to include calcium ion as taught by Chen in
the CMP system of Moeggenborg, given that the purpose for adding calcium
ion in Chen is to promote high-rate metal polishing, whereas Moeggenborg’s
purpose is to suppress the removal rate of the dielectric layer without
substantially affecting the metal layer removal rate (Br. 12).
We cannot agree. For the reasons detailed by the Examiner (Ans. 8,
13, and 19), an artisan would have combined the references in the manner
proposed in order to obtain better planarity and polishing rates as taught in
Chen. Chen’s desire to enhance the metal removal rate is not inconsistent
with Moeggenborg’s desire to suppress the removal rate of the dielectric
layer without substantially affecting the removal rates of other layers
including metal layers. Moeggenborg does not discourage enhancing the
metal removal rate. Rather, Moeggenborg discourages suppressing the
metal removal rate. Accordingly, we share the Examiner’s conclusion that
the use of calcium ion in the claimed range in Moeggenborg’s CMP system
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would have been obvious in order to obtain better planarity and polishing
rates as taught by Chen.
Appellants argue that “[t]he only way in which the combined
disclosures of the cited references can be considered as teaching or
suggesting the present invention as defined by the appealed claims is
through the use of hindsight” (Br. 13). Appellants' unembellished statement
to the contrary reveals no error in the Examiner's rationale.
Accordingly, we determine that a preponderance of the evidence
favors the Examiner’s conclusion of obviousness as to appealed claim 12.

Reference Not Relied Upon
We note that the Examiner refers to a reference (Dinesh,
2002/0192942 A1, Dec. 19, 2002) in rebuttal to Appellants’ argument (Ans.
17). As Dinesh was neither positively recited in the Answer’s “Evidence
Relied Upon” section nor positively applied in any statement of rejection of
the rejected claims, we will not address this reference. See In re Hoch, 428
F.2d 1341, 1342 n. 3 (CCPA 1970)(“Where a reference is relied on to
support a rejection, whether or not in a ‘minor capacity,’ there would appear
to be no excuse for not positively including the reference in the statement of
the rejection.”).

Conclusion
The decision of the Examiner is affirmed.

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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

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