Ex Parte Mishima et al

Patent Trial and Appeal Board

Sep 26, 2017

13172397 (P.T.A.B. Sep. 26, 2017)

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.
13/172,397 06/29/2011 Kouji Mishima P7127US00 7222
38834 7590 09/28/2017
WESTERMAN, HATTORI, DANIELS & ADRIAN, LLP
1250 CONNECTICUT AVENUE, NW
SUITE 700
WASHINGTON, DC 20036
EXAMINER
PHAM, THOMAS T
ART UNIT PAPER NUMBER
1713
NOTIFICATION DATE DELIVERY MODE
09/28/2017 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
patentmail @ whda.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KOUJI MISHIMA, TAKAFUMI SAKURADA, and
TOMOKAZU SHIMADA
Appeal 2016-008177
Application 13/172,397
Technology Center 1700
Before JAMES C. HOUSEL, JENNIFER R. GUPTA, and
DEBRA L. DENNETT, Administrative Patent Judges.
HOUSEL, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellants1 appeal from the
Examiner’s decision finally rejecting claims 12—19, 22—37, 40-49, 52, and
53. We have jurisdiction over the appeal under 35 U.S.C. § 6(b).
We REVERSE.2
1 According to Appellants, the real party in interest is HITACHI
CHEMICAL COMPANY, LTD. Appeal Br. 2.
2 Our decision refers to the Specification (Spec.) filed June 29, 2011, the
Examiner’s Final Office Action (Final Act.) dated December 3, 2014,
Appellants’ Appeal Brief (Appeal Br.) filed December 30, 2015, the
Appeal 2016-008177
Application 13/172,397
STATEMENT OF THE CASE
The invention relates to a chemical mechanical polishing (CMP)
method for polishing of semiconductor devices in wiring formation steps.
Spec. 11. Appellants disclose that in wiring formation by the damascene
process, it is common to employ a two-stage polishing step comprising a
first polishing step in which a conductive substance layer is polished and a
second polishing step in which a barrier layer between the conductive
substance layer and an insulating film is polished. Id. ^1. In order to
improve flatness, Appellants disclose that this second polishing step may
also polish portions of the insulating film and the conductive substance
layer, requiring that the CMP composition be designed in consideration of a
balance between polishing speeds for each of these materials. Id. 110.
Appellants disclose that, in addition to dishing caused by excess shaving of
the conductive substance layer, local scoop-like removal of the insulating
film occurs near the conductive layer creating a seam which can lead to
increased wiring resistance. Id. 13—14.
Therefore, Appellants disclose that seam generation can be reduced by
using a CMP composition employing both a metal corrosion inhibitor
comprising a compound with a l,2,3-triazolo[4,5-b]pyridine skeleton, and an
abrasive grain having a positive zeta potential. Id. 117.
Claim 28, reproduced below from the Claims Appendix to the Appeal
Brief, is illustrative of the subject matter on appeal. The limitation at issue
is italicized.
Examiner’s Answer (Ans.) dated July 20, 2016, and Appellants’ Reply Brief
(Reply Br.) filed August 31, 2016.
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Application 13/172,397
28. A polishing method comprising
a step of preparing a substrate comprising an interlayer
insulating film and a barrier layer,
a step of preparing a CMP polishing slurry comprising (A) a
metal corrosion inhibitor containing a compound with a 1,2,3-
triazolo[4,5-b]pyridine skeleton, (B) an abrasive grain having a zeta
potential of+6mV to +30mV in the CMP polishing slurry, (C) a metal
oxide solubilizer and (D) an oxidizing agent, and
a polishing step of polishing at least the barrier layer and the
interlayer insulating film using the CMP polishing slurry to remove a
portion of the barrier layer and a portion of the interlayer insulating
film,
wherein (B) the abrasive grain comprises colloidal silica.
Remaining independent claim 12 similarly recites a polishing method
employing a CMP slurry comprising the l,2,3-triazolo[4,5-b]pyridine
skeleton and the abrasive grain comprising colloidal silica and having a zeta
potential of +6mV to +30mV in the CMP slurry.
REJECTIONS
The Examiner maintains, and Appellants request our review of, the
following grounds of rejection under 35 U.S.C. § 103(a):
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Application 13/172,397
1. Claims 12-19, 22, 23, 26-37, 40, 41, and 4AA9 as
unpatentable over Carter3 in view of Kamiya4 and Siddiqui;5
2. Claims 24, 25, 42, and 43 as unpatentable over the combination
of Carter, Kamiya, and Siddiqui above, and further in view of Lee;6
and
3. Claims 52 and 53 as unpatentable over the combination of
Carter, Kamiya, Siddiqui above, and further in view of Asano.7
ANALYSIS
A dispositive issue in this appeal is whether the Examiner reversibly
erred in determining that Appellants’ evidentiary showing set forth in the
Specification and the Declaration under 37 C.F.R. § 1.132 of Kouji Mishima
(Dec.), filed November 17, 2014 fails to establish unexpected results in a
CMP method using a CMP slurry comprising, among other things, a metal
corrosion inhibitor containing a compound with a l,2,3-triazolo[4,5-
bjpyridine skeleton and an abrasive grain comprising colloidal silica having
a zeta potential of +6mV to +30mV in the CMP slurry. We answer this
question in the affirmative and, therefore, will not sustain the Examiner’s
obviousness rejections.
The Examiner finds Carter teaches a CMP method as claimed except,
in relevant part, for a teaching that Carter’s abrasive grain comprising
aluminum-doped colloidal silica has a zeta potential of +6mV to +30mV.
3 Carter et al., US 2006/0030158 Al, published February 9, 2006 (“Carter”).
4 Kamiya et al., US 2010/0009540 Al, published January 14, 2010
(“Kamiya”).
5 Siddiqui et al., US 2004/0107650 Al, published June 10, 2004
(“Siddiqui”).
6 Lee et al., US 2010/0164106 Al, published July 1, 2010 (“Lee”).
7 Asano et al., US 6,565,619 Bl, issued May 20, 2003 (“Asano”).
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Application 13/172,397
Ans. 2—3. The Examiner finds Siddiqui teaches a CMP including an
aluminum-doped silica having a zeta potential of about +30mV to +40 mv.
Id. at 4. The Examiner concludes it would have been obvious to use an
aluminum-doped colloidal silica with a zeta potential of about +30mV to
+40 mV in Carter because both Carter and Siddiqui teaches CMP slurries
including aluminum-doped silica and because Siddiqui teaches a method for
producing the aluminum-doped silica that would be useful in producing
Carter’s aluminum-doped silica with a reasonable expectation of success.
Id.; see also, id. at 7—8.
Appellants argue, inter alia, that the use of a CMP slurry comprising a
combination of a metal corrosion inhibitor containing a compound with a
l,2,3-triazolo[4,5-b]pyridine skeleton and an abrasive grain having a zeta
potential of +6mV to +30 mV in the CMP slurry, as recited in independent
claims 12 and 28 yield unexpected results, at least in terms of the amount of
seam generated relative to the prior art. Appeal Br. 6. In particular,
Appellants direct attention to Tables 1—4 of the Specification as well as the
Mishima Declaration in support of this argument. Id. at 7—12. For the
reasons expressed in the Appeal and Reply Briefs, we are persuaded that
Appellants’ CMP method using the CMP slurry comprising a compound
with a l,2,3-triazolo[4,5-b]pyridine skeleton and an abrasive grain of
colloidal silica having a zeta potential of +6mV to +30mV in the CMP slurry
produces unexpected results with regard to the generation of seam in the
polished substrate.
In doing so, we note that Appellants’ results as depicted in the graph
of the amount of seam versus the zeta potential of the abrasive grain clearly
shows low seam generation beginning between OmV and +10mV which
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Application 13/172,397
continues up to Appellants’ final data point at +28mV, thereby suggesting a
trend that the ordinary artisan would have reasonably expected to continue
up to, and even beyond,+3OmV. See Dec. 1 5. Therefore, we find no merit
to the Examiner’s criticism of Appellants’ evidentiary showing as lacking
data at the end point of Appellants’ claimed range of zeta potentials. See
Ans. 8, 10.
In addition, the Examiner errs in not crediting Appellants’ unexpected
results of significantly reduced seam generation because the claims do not
recite anything regarding seams (Ans. 8). Appellants need not explicitly
claim that which is implicitly or inherently being accomplished by the
operation of their method, especially where they recognized and disclosed in
the Specification the result shown to have been unexpected. See In re
Papesc/*,315F.2d381,391, 137USPQ 43,51 (CCPA 1963) (“From the
standpoint of patent law, a compound and all of its properties are
inseparable; they are one and the same thing.”).
The Examiner further errs in discrediting Appellants’ evidence as not
commensurate in scope with the claims with regard to the test structures
used in the CMP polishing experiments (Ans. 9). The Examiner’s position
is merely conclusory because the Examiner neither provides any technical
reasoning nor directs our attention to any evidence supporting the notion that
the ordinary artisan would have considered the test structure to be a critical
variable in the CMP process.
The Examiner likewise has not shown that either the polymethacrylic
acid or the isopropyl alcohol used in the experiments are not among the
components recited in the claims (Ans. 9). Appellants disclose that organic
solvents may be added to reduce the polishing speed ratio between the
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Application 13/172,397
insulating film, the barrier layer, and the conductive substance layer. Id. 1
10. Appellants also teach that the organic solvent improves the wettability
of the CMP composition while improving the polishing speed. Id. 126.
Appellants disclose isopropyl alcohol among the list of possible organic
solvents useful in the invention. Given these teachings and the lack of any
technical reasoning or evidence indicating that the selection of organic
solvent would have been expected to be critical to the results obtained by
Appellants, we are not convinced that Appellants’ results are not
commensurate in scope with the claims as to the organic solvent.
With regard to the use of a polymethacrylic acid (or polyacrylic acid)
in the experiments, the Examiner is correct that the claims do not require a
water-soluble polymer. Compare claims 12 and 28 with Spec. 1100,
Table 1. Notwithstanding this fact, the Examiner has not carried the burden
of establishing that the inclusion of a water-soluble polymer obviates the
unexpected results obtained. In this regard, we note that each of Appellants’
experiments, including the comparative examples, used the same kind and
amount of water-soluble polymer. Compare Spec. 1100, Table 1 with Spec.
11101 and 102, Tables 2 and 3.
Finally, the Examiner determines that Appellants’ results are
insufficient because only 3 different compounds having the required
l,2,3-triazolo[4,5-b]pyridine skeleton were tested at a single concentration,
especially “considering the vast variety of possible compounds having a
l,2,3-triazolo[4,5-b]pyridine skeleton and a vast variety of possible
concentrations.” Ans. 9. With regard to the concentration, the Examiner has
not articulated why this parameter is critical to the results obtained, or why
the ordinary artisan would not be able to determine a working range of
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Application 13/172,397
concentrations from Appellants’ disclosure. With regard to the variety of
possible compounds, we note Appellants disclose examples of possible
compounds having a l,2,3-triazolo[4,5-b]pyridine skeleton, three of which
were included in Appellants’ test results. The Examiner does not explain
why the ordinary artisan would not reasonably have expected the remaining
listed examples to similarly yield reduction in seam generation given the
results of the three representative examples tested.
Therefore, we are convinced that Appellants have established
unexpected results and the Examiner erred in maintaining the obviousness
rejection.
DECISION
Upon consideration of the record, and for the reasons given above and
in the Appeal and Reply Briefs, the decision of the Examiner rejecting
claims 12—19, 22—37, 40-49, 52, and 53 under 35 U.S.C. § 103(a) is
reversed.
REVERSED
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