Juergen Schwandner et al.

Patent Trials and Appeals Board

Nov 20, 2019

13038455 - (D) (P.T.A.B. Nov. 20, 2019)

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.
13/038,455 03/02/2011 Juergen Schwandner 812488 8875
95683 7590 11/20/2019
Leydig, Voit & Mayer, Ltd. (Frankfurt office)
Two Prudential Plaza, Suite 4900
180 North Stetson Avenue
Chicago, IL 60601-6731
EXAMINER
ROSE, ROBERT A
ART UNIT PAPER NUMBER
3723
NOTIFICATION DATE DELIVERY MODE
11/20/2019 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):
chgpatent@leydig.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte JUERGEN SCHWANDNER and MICHAEL KERSTAN
____________

Appeal 2018-000868
Application 13/038,455
Technology Center 3700
____________

Before GEORGE R. HOSKINS, SCOTT C. MOORE, and
LEE L. STEPINA, Administrative Patent Judges.

HOSKINS, Administrative Patent Judge.

DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134(a), Appellant1 appeals from the
Examiner’s decision to reject claims 1–6 and 8–21 in this application, under
35 U.S.C. § 103(a), as unpatentable over Kozasa (US 7,540,800 B2, issued
June 2, 2009) and Hishiki (US 2003/0109209 A1, published June 12, 2003).
Claim 7 is canceled. See Appeal Br. 2, 10. The Board has jurisdiction over
the appeal under 35 U.S.C. § 6(b).
We REVERSE.

1 We use the word “Appellant” to refer to “applicant” as defined in
37 C.F.R. § 1.42. Appellant identifies Siltronic AG as the real party in
interest. Appeal Br. 1.
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CLAIMED SUBJECT MATTER
Claim 1 is the sole independent claim on appeal, and it recites (with
emphases added to the limitations at issue here):
1. A method of polishing a semiconductor wafer, the method
comprising:
polishing a surface of the semiconductor wafer using a
polishing pad while supplying a polishing agent slurry
containing abrasives during a first step, the polishing pad being
free of abrasives and including a first surface that contacts the
semiconductor wafer, the first surface having a surface structure
including elevations, the structure of the first surface being
structured by one of chemical etching, grinding, buffing,
sintering or furrowing;
subsequently ending the supply of polishing agent slurry;
and
polishing the surface of the semiconductor wafer so as to
decrease a surface roughness of the wafer using the polishing
pad in a second step while supplying a polishing agent solution
having a pH value of at least 12 that is free of solids.
Appeal Br. 10 (Claims App.) (emphases added).
OPINION
Claim 1
The issues presented on appeal center on the limitations in claim 1
reciting “polishing the surface of the semiconductor wafer so as to decrease
a surface roughness of the wafer . . . while supplying a polishing agent
solution having a pH value of at least 12.” Appeal Br. 10 (Claims App.)
(emphases added). The Examiner firstly finds Kozasa discloses this subject
matter. The Examiner alternatively determines, if Kozasa does not disclose
this subject matter, it would have been obvious to modify Kozasa to include
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this subject matter. For the following reasons, we do not sustain either
conclusion, so we do not sustain the rejection of claim 1.
a. Whether Kozasa discloses decreasing surface
roughness while supplying a polishing solution having
a pH value of at least 12
The Examiner finds Kozasa discloses using a polishing agent solution
having a “high value of pH.” Final Act. 2. In particular, according to the
Examiner, Kozasa discloses “the pH value is set within a range of 10–12 in
the second polishing step” (Kozasa, 2:41–44 (emphasis added)), so “at least
one value [i.e., 12] lies within the range recited [i.e., at least 12]” in claim 1.
Id. at 4 (emphasis added); Ans. 5.
Appellant disputes the Examiner’s finding. Appeal Br. 4–5.
According to Appellant, Kozasa’s Figure 4 “teaches that, at a pH of 12, the
surface roughness of the wafer increases, which is opposite to the
requirements of claim 1.” Id. (emphasis by Appellant). Appellant points out
Kozasa’s Figure 4 shows surface roughness decreasing over time at pH
values of 10 and 11, but those values are outside of the claimed pH range of
at least 12. Id. Appellant further contends “Kozasa is silent” as to pH
values above 12. Id.
The Examiner answers that “it is immaterial that the surface becomes
slightly rougher” when applying Kozasa’s second step polishing solution at
a pH of 12, because Kozasa’s overall process results in a wafer surface that
“is smoother than an initial starting roughness.” Ans. 6. The Examiner
finds: “Even for pH of 12, the final roughness of 1.2 µm after 8 minutes can
still be lower if the initial starting roughness is, for example 1.4 µm.” Id.
(emphases added)
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We determine Kozasa does not disclose a second polishing step that
“decreas[es] a surface roughness of the wafer . . . while supplying a
polishing agent solution having a pH value of at least 12,” as recited in
claim 1. The Examiner correctly finds Kozasa discloses a second polishing
step that supplies a polishing agent solution having a pH value of 12, which
is at least 12 as required by claim 1. See Kozasa, 2:41–44, 6:16–17; see also
Appeal Br. 5 (stating that in Kozasa, “the pH of 12 would only be used with
one particular micro-roughness achieved in the first polishing step”).
However, claim 1 requires more than that, in reciting that the second
polishing step “decreas[es] a surface roughness of the wafer.” Kozasa’s
only disclosure pertaining to the effect of supplying a polishing agent
solution having a pH of 12 is that the solution increases, rather than
decreases, the surface roughness of the wafer. See Kozasa, Fig. 4, 6:19–25
(Fig. 4 reflects that “the micro-roughness Rq degrades when the polishing
time t becomes long at pH12 on account of too strong alkaline property,”
and “the micro-roughness Rq decreases in accordance with the polishing
time t at pH11 and pH10 levels”).
We disagree with the Examiner’s conclusion that “it is immaterial”
whether Kozasa’s second polishing step decreases the wafer’s surface
roughness, so long as Kozasa’s overall process decreases the wafer’s surface
roughness. This conclusion overlooks the final clause of claim 1, which
specifically requires that the second polishing step decreases the wafer’s
surface roughness. See Appeal Br. 10 (Claims App.). Further, the
Examiner’s speculation that a pH of 12 can decrease the wafer’s surface
roughness if the initial starting roughness is 1.4 µm is not supported by
Kozasa’s disclosure. See, e.g., Kozasa, Fig. 4 (not reflecting what happens
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when applying a pH 12 solution to a wafer surface having a roughness of
1.4 µm).
Further, to the extent the Examiner relies upon the mere capability of
Kozasa’s apparatus to supply a pH of at least 12, this overlooks that claim 1
is directed to a method of polishing not an apparatus for polishing. Thus,
capability alone is insufficient to establish anticipation here.
For the foregoing reasons, we do not sustain the Examiner’s finding
that Kozasa discloses decreasing the surface roughness of a wafer while
supplying a polishing solution having a pH value of at least 12.
b. Whether it would have been obvious to modify Kozasa
to decrease surface roughness while supplying
a polishing solution having a pH value of at least 12
The Examiner determines, if Kozasa does not disclose decreasing the
surface roughness of a wafer while supplying a polishing solution having a
pH value of at least 12, then it would have been obvious to modify Kozasa
to do so. See Final Act. 2–5. The Examiner concludes “[t]he pH value
chosen is seen as one of design choice depending upon the conditions of
polishing and desired end result.” Id. at 2–3. The Examiner acknowledges
Kozasa’s Figure 4 shows roughness “increasing with time during polishing”
using a pH of 12, but notes Figure 4 “also shows other curves in which the
roughness decreases with time.” Id. at 3. Further according to the
Examiner, “Figure 4 is representative of only one particular set of polishing
parameters,” and “whether the ultimate roughness of the wafer surface
increases or decreases as a result of the polishing, would depend upon the
initial roughness of the wafer prior to polishing.” Id. For example, the
Examiner determines “a highly roughened initial wafer surface would
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necessarily be rendered less rough after polishing, regardless of the pH of
the polishing solution.” Id. at 3–4 (emphases added).
The Examiner further determines “the pH range of the polishing slurry
is a recognized results effective variable which would be arrived at by mere
routine experimentation” by a person of ordinary skill in the art. Final
Act. 4. In support, the Examiner concludes Kozasa’s disclosed pH range of
10–12 is only “a ‘preferred’ range, and is not assigned criticality, as
evidenced by the omission of a pH range” in Kozasa’s claim 1. Id. Further
according to the Examiner, Kozasa teaches “to alter the pH level in
dependence upon” several different considerations, such as “the applied load
current from the first polishing step.” Id. (citing Kozasa, 3:1–67).
Appellant disputes the foregoing analyses. See Appeal Br. 3–5.
According to Appellant, Kozasa’s Figure 4 “teaches that, at a pH of 12, the
surface roughness of the wafer increases, which is opposite to the
requirements of claim 1.” Id. at 4 (emphasis by Appellant). Appellant
contends the Examiner errs in relying on the other curves of Kozasa’s
Figure 4 to support the rejection, because the other curves concern pH values
of 10 and 11, which are outside the claimed pH range of “at least 12.” Id.
Appellant asserts “Kozasa is silent to any set of polishing conditions by
which a decrease in surface roughness could be achieved using a pH of at
least 12.” Id. at 4–5. Further in Appellant’s view, “the pH is not recognized
as being a results-effective variable,” and “[i]f anything, based on the
teachings of [Kozasa], one would expect that using the pH recited in the
claims of the present application would achieve the opposite result to the one
claimed.” Id. at 3.
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The Examiner responds that Appellant erroneously concludes Kozasa
“indicates a roughening of the surface rather than a smoothing of the
surface.” Final Act. 4–5 (citing Kozasa, 1:21–22, 2:1–13); Ans. 5–6. In
particular, according to the Examiner, “depending upon the original state of
the wafer surface prior to performing the method, the surface can be either
of higher or lower roughness.” Ans. 6. Thus, the Examiner takes “the
position that those of ordinary skill in the art would have recognized that the
pH value of the alkali agent may be adjusted to provide a desired final
surface roughness for the wafer, depending upon the composition of the
wafer and [its] initial surface condition.” Id. The Examiner additionally
finds Kozasa “offers several of the same suitable examples (KOH, NaOH,
ammonium hydroxide)” as are disclosed in Appellant’s Specification to be
appropriate alkaline agents for use in the second polishing step. Id.
(emphasis omitted) (citing Kozasa, 2:28–30).
In reply, concerning Kozasa’s disclosure of the same alkali materials
as disclosed in Appellant’s Specification for the second polishing step,
Appellant contends “the results of polishing depend on more than just a
particular composition of a polishing agent.” Reply Br. 3. According to
Appellant, “Kozasa does not suggest how such a second polishing step could
be performed so that roughness decreases when using a solution with a pH
of 12 or more.” Id.
Based on our review of the foregoing, we conclude the rejection
presently before us is not sustainable. “A reference may be said to teach
away when a person of ordinary skill, upon reading the reference, would be
discouraged from following the path set out in the reference, or would be led
in a direction divergent from the path that was taken by the applicant.”
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Polaris Indus., Inc. v. Arctic Cat, Inc., 882 F.3d 1056, 1069 (Fed. Cir. 2018)
(quoting Ricoh Co., Ltd. v. Quanta Computer Inc., 550 F.3d 1325, 1332
(Fed. Cir. 2008)). Further, “a reference ‘must [be] considered for all it
taught, disclosures that diverged and taught away from the invention at hand
as well as disclosures that pointed towards and taught the invention at
hand.’” Id. (quoting Ashland Oil, Inc. v. Delta Resins & Refractories, Inc.,
776 F.2d 281, 296 (Fed. Cir. 1985)). Thus, “even if a reference is not found
to teach away, its statements regarding preferences are relevant to a finding
regarding whether a skilled artisan would be motivated to” modify the
reference in the manner claimed. Id. (citing Apple Inc. v. Samsung Elecs.
Co., 839 F.3d 1034, 1051 n.15 (Fed. Cir. 2016) (en banc)).
Here, we conclude the rejection presently before us errs in not
considering Kozasa for everything that it teaches, including disclosures that
diverge or teach away from Appellant’s claimed invention. It is undisputed
that the only disclosure in Kozasa concerning the effects of using a polishing
solution having a pH of “at least 12,” as recited in claim 1, is that using a
polishing solution having a pH equal to 12 increases rather than decreases
surface roughness. See Kozasa, Fig. 4, 2:41–44, 6:16–25. Kozasa therefore
indicates that, while a PH of 12 may be used, “the second polishing step . . .
is preferably conducted at a pH value from pH10 or more to less than
pH12.” Id. at 2:28–33 (emphasis added), 6:67–7:6, 9:1–5 (claim 2).
Kozasa, also, is silent concerning pH values of greater than 12. Even if
these disclosures in Kozasa do not rise to the level of teaching away from
decreasing the surface roughness of a wafer while supplying a polishing
solution having a pH value of at least 12, they nonetheless are relevant to
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determining whether a skilled artisan would have been motivated to modify
Kozasa in such a manner.
There is little evidence of record to support the Examiner’s conclusion
that it would have been obvious to decrease the surface roughness of a wafer
while supplying a polishing solution having a pH value of at least 12, even
though Kozasa teaches that such a pH would increase surface roughness.
We agree with the Examiner’s conclusion that Kozasa indicates the pH value
of a polishing agent solution is a result-effective variable when polishing
semiconductor wafers. See, e.g., Kozasa, 2:59–3:18. However, that fact
alone is insufficient to overcome Kozasa’s expressly stated preference for
using pH values of less than 12 to decrease the surface roughness of a wafer.
The Examiner, additionally, finds that under some conditions it may be that
using pH values of at least 12 will decrease the surface roughness of a wafer.
See Final Act. 3–4 (pertinent factors include pH value of the polishing agent
solution, the initial roughness of the wafer, and load current); Ans. 4–6
(same). There is, however, no evidence of record to support this finding.
For example, the Examiner does not cite any evidence of record that reflects
knowledge or experience in the prior art of using pH values of at least 12 to
decrease the surface roughness of a wafer, regardless of other conditions
applied. Thus, we give little weight to the Examiner’s speculation as to what
might occur under various such conditions.
For the foregoing reasons, we do not sustain the Examiner’s
determination that it would have been obvious to modify Kozasa to decrease
the surface roughness of a wafer while supplying a polishing solution having
a pH value of at least 12.
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c. Conclusion regarding claim 1
The Examiner’s additional consideration of Hishiki does not cure the
foregoing deficiencies of Kozasa. See Final Act. 3 (citing Hishiki for
polishing pad having elevations, not for pH of polishing solution); Ans. 2–3
(same). Therefore, for the reasons provided above, we do not sustain the
Examiner’s rejection of claim 1 as unpatentable over Kozasa and Hishiki.
Claims 2–6 and 8–21
The Examiner’s additional consideration of dependent claims 2–6 and
8–21 does not cure the foregoing deficiencies of Kozasa in relation to
claim 1. See Final Act. 2–5. Therefore, for the reasons provided above, we
do not sustain the Examiner’s rejection of claims 2–6 and 8–21 as
unpatentable over Kozasa and Hishiki.
CONCLUSION
In summary:
Claims
Rejected
35 U.S.C.
§
References Affirmed Reversed
1–6, 8–21 103 Kozasa, Hishiki 1–6, 8–21
REVERSED