Ex Parte Ellmer et al

Patent Trial and Appeal Board

Sep 30, 2014

12516713 (P.T.A.B. Sep. 30, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
_________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte KLAUS ELLMER
and THOMAS UNOLD
__________

Appeal 2013-002047
Application 12/516,713
Technology Center 1700
___________

Before ADRIENE LEPIANE HANLON, KAREN M. HASTINGS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON APPEAL

A. STATEMENT OF THE CASE
The Appellants appeal under 35 U.S.C. § 134 from a final rejection of
claims 8–15, which are all of the pending claims. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM.
Claim 8 is representative of the subject matter on appeal and is reproduced
below from the Claims Appendix of the Appeal Brief dated June 22, 2012 (“Br.”).
8. A method of reactive magnetron sputtering for deposition of a
chalcopyrite absorber layer for thin-film solar cells on a substrate,
using at least one magnetron sputter source with at least one copper
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target, and using an inert gas and a chalcogen-containing reactive gas
in a magnetron plasma, the method comprising:
introducing the chalcogen-containing reactive gas directly at the
substrate;
setting the chalcogen-containing reactive gas fraction at 5 to
30% of the inert gas fraction in the magnetron plasma;
setting a sputtering pressure of between 1 and 2 Pa;
applying a negative bias voltage to the substrate during the
reactive magnetron sputtering;
exciting the magnetron plasma by radio frequency AC voltage
above 6 MHz;
heating the substrate to a temperature between 350 ºC and
500 ºC; and
performing a copper-poor deposition by disposing different
targets, serial in time, in the at least one magnetron sputter source and
operating the targets at the same sputtering power, or by disposing
same targets, parallel in time, in the at least one magnetron sputter
source and operating the targets at different sputtering powers, so as to
obtain stoichiometry gradients.
The claims on appeal stand rejected as follows: (1) claims 8–12 under
35 U.S.C. § 103(a) as unpatentable over Unold1 in view of Shao,2 Kondo,3 and
Hollars;4 (2) claim 13 under 35 U.S.C. § 103(a) as unpatentable over Unold in

1 Thomas Unold et al., Reactive Magnetron Sputtering of CuInS2 Solar Cells – The
Influence of the Deposition Conditions on Structural and Electronic Properties
and Solar Cell Efficiency, 15th International Photovoltaic Science & Engineering
Conference 503-04 (2005).
2 Lexi Shao et al., The one-step vacuum growth of high-quality CuInS2 thin film
suitable for photovoltaic applications, 6 MATERIALS SCIENCE IN SEMICONDUCTOR
PROCESSING 397-400 (2003).
3 Ken-ichi Kondo et al., Growth and Characterization of CuInS2 Films grown by Rf
Ion-Plating, 36 JPN. J. APPL. PHYS. 6668-71 (1997).
4 US 6,974,976 B2, issued December 13, 2005.
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view of Shao, Kondo, Hollars, and Thornton;5 (3) claim 14 under 35 U.S.C.
§ 103(a) as unpatentable over Unold in view of Shao, Kondo, Hollars, and
Chapin;6 and (4) claim 15 under 35 U.S.C. § 103(a) as unpatentable over Unold in
view of Shao, Kondo, Hollars, Chapin, and Takahashi.7
As to rejection (1), the Appellants do not argue the patentability of claims 8–
12 as a group. Therefore, for purposes of this appeal, claims 9–12 stand or fall
with the patentability of claim 8. As for the remaining rejections on appeal, the
Appellants do not present arguments in support of the separate patentability of any
of the claims subject to rejections (2)–(4). See Br. 6. Therefore, the patentability
of claims 13, 14, and 15 will be considered based on the arguments set forth in
support of the patentability of claim 8.
B. DISCUSSION
The Examiner finds that Unold discloses a method of reactive magnetron
sputtering for large area deposition of a chalcopyrite absorber layer for thin film
solar cells on a substrate. The Examiner finds the disclosed method uses at least
one magnetron sputter source with at least one copper target as well as an inert gas
and a chalcogen-containing reactive gas in a magnetron plasma. The Examiner
finds the method includes the steps of introducing the chalcogen-containing
reactive gas directly at the substrate; setting a sputtering pressure of between 1 and
2 Pa; and heating the substrate to a temperature between 350 and 500 degrees C as
recited in claim 8. Ans. 5.8

5 John A. Thornton & T.C. Lommasson, Magnetron Reactive Sputtering of
Copper–Indium–Selenide, 16 SOLAR CELLS 165-80 (1986).
6 US 4,166,784, issued September 4, 1979.
7 US 2007/0123004 A1, published May 31, 2007.
8 Examiner’s Answer dated August 24, 2012.
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The Examiner relies on Shao, Kondo, and Hollars to teach the remaining
steps recited in claim 8. In particular, the Examiner finds that Shao teaches using a
chalcogen-containing reactive gas fraction at 30% of the inert gas fraction in the
magnetron plasma and exciting the magnetron plasma by radio frequency AC
voltage greater than about 6 MHz. Id. at 6. The Examiner finds that Kondo
teaches applying a negative bias during physical vapor deposition to control the
surface morphology and crystallinity of the film. Id. The Examiner finds that
Hollars teaches performing low copper deposition by disposing different targets
serial in time. Id. at 7.
The Appellants argue that Unold describes a reactive magnetron sputtering
process which avoids a large copper ratio. The Appellants argue that Shao, on the
other hand, discloses a process “in which ‘[a]ll films are Cu-rich.’” Br. 4 (quoting
Shao 398). Thus, the Appellants argue that one of ordinary skill in the art “would
not look to [the process of Shao] which only produces copper-rich layers to modify
a process in which excess copper should be avoided.” Br. 4.
The Appellants also argue that the Examiner’s reason for selecting the
parameters from Shao is “faulty.” Id. According to the Appellants, “the
motivation for ‘setting the chalcogen-containing reactive gas fraction at 5 to 30%
of the inert gas fraction in the magnetron plasma’ and ‘exciting the magnetron
plasma by radio frequency AC voltage above 6 MHz’ is that ‘it allows for
controlling the atomic ratio of the film.’” Id. (citing Final 4–59). However, the
Appellants argue that Shao does not suggest using a chalcogen-containing reactive
gas in any range below 30%. Id. As for the excitation frequency, the Appellants

9 Final Office Action dated February 28, 2012.
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argue that Shao does not disclose or suggest that the excitation frequency has any
bearing on atomic ratio. Id. at 5.
In response, the Examiner finds that Unold produces a copper-poor
deposition using 33% reactive gas. The Examiner finds that “[s]ince the 33%
teaching of Unold is close enough to Appellants 30% it is believed to produce a
film having the same properties as Appellants (i.e. a copper[-]poor film).” Ans. 11
(citing Titanium Metals Corp. of Am. v. Banner, 778 F.2d 775 (Fed. Cir. 1985)).
The Appellants do not direct us to any evidence to the contrary.
As for the excitation frequency recited in claim 8, the Examiner points out
that Shao teaches the excitation frequency to be 13.4 MHz. Ans. 16. The
Examiner also directs our attention to Hollars. Hollars discloses a process for
depositing a copper-poor coating for a solar cell using a reactive magnetron
sputtering process.10 The Examiner finds, and the Appellants do not dispute, that
Hollars teaches that the composition of the deposited copper deficient coating is
dependent on many factors, including sputtering pressure and sputtering power.
Id. at 12; see also Hollars, col. 14, ll. 25–27, 36–41. Thus, one of ordinary skill in
the art would have understood that sputtering parameters, including excitation
frequency, are result-effective variables. See In re Boesch, 617 F.2d 272, 276
(CCPA 1980) (“discovery of an optimum value of a result effective variable in a
known process is ordinarily within the skill of the art”).
As for the remaining limitations recited in claim 8 that are not disclosed in
Unold, the Examiner makes specific findings of fact based on the teachings of

10 Hollars discloses that the coating may be deposited using conventional planar
magnetrons or cylindrical rotary magnetrons. See, e.g., Hollars, col. 13, ll. 55-57;
id. at col. 15, ll. 3-6. Hollars also discloses that AC reactive sputtering is an
alternative to DC sputtering. See, e.g., Hollars, col. 15, ll. 41-44.
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Kondo and Hollars and specific conclusions of law based on the combined
teachings of Unold, Kondo, and/or Hollars. See Ans. 6–8. The Appellants do not
direct us to any error in those factual findings or legal conclusions. Rather, the
Appellants generally argue that “the processes of Kondo (rf ion-plating, see
abstract) and Hollars (roll-to-roll vacuum deposition, see col. 1, lines 9–15) are
materially different from the reactive magnetron sputtering of Unold.” Br. 5. For
this reason, the Appellants contend that the combination of Unold with Kondo and
Hollars is improper. Id.
The mere fact that the processes disclosed in Kondo and Hollars may be
different from the process disclosed in Unold is not persuasive of reversible error.
The Examiner finds, and the Appellants do not dispute, that Unold, Kondo, and
Hollars disclose physical vapor deposition processes. Ans. 16. Thus, absent any
evidence or technical reasoning to the contrary, one of ordinary skill in the art
would have found the teachings of Kondo and Hollars relevant to the process
disclosed in Unold.
Finally, the Appellants argue that the claimed method provides surprising
and unexpected results. The Appellants rely on paragraphs 11, 14, 15, and 25 of
the original Specification for support. Br. 3–4, 5.
Significantly, the portions of the Specification relied on by the Appellants do
not disclose comparative test data but rather contain conclusory statements relating
to the disclosed method. “It is well settled that unexpected results must be
established by factual evidence. Mere argument or conclusory statements in the
specification does not suffice.” In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir.
1984); see also Ans. 11.
For the reasons set forth above and in the Examiner’s Answer, the § 103(a)
rejections are sustained.
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C. DECISION
The decision of the Examiner is affirmed.
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).
AFFIRMED

cdc