Ex Parte Smith et al

Patent Trial and Appeal Board

Apr 18, 2017

12890428 (P.T.A.B. Apr. 18, 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.
7923.P041 8333
EXAMINER
DANICIC, CHRISTOPHER
ART UNIT PAPER NUMBER
1758
MAIL DATE DELIVERY MODE
12/890,428 09/24/2010
04/19/201784372 7590
SunPower/ BSTZ
Blakely Sokoloff Taylor & Zafman LLP
1279 OAKMEAD PARKWAY
SUNNYVALE, CA 94085-4040
David Smith
04/19/2017 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 PATENT TRIAL AND APPEAL BOARD
Ex parte DAVID SMITH, HELEN LIU, TIM DENNIS,
JANE MANNING, HSIN-CHIAO LUAN,
ANN WALDHAUER, GENEVIEVE A. SOLOMON,
BRENDA PAGULAYAN MALGAPU, and
JOSEPH RAMIREZ
Appeal 2016-002254
Application 12/890,428
Technology Center 1700
Before MICHAEL P. COLAIANNI, JENNIFER R. GUPTA, AND
LILAN REN, Administrative Patent Judges.
GUPTA, Administrative Patent Judge.
DECISION ON APPEAL1
Appellants2 appeal under 35 U.S.C. § 134(a) from the Examiner’s
decision finally rejecting claims 1, 2, 7, 8, and 23—26. We have jurisdiction
under 35 U.S.C. § 6(b). We affirm.
1 In this decision, we refer to Appellants’ Specification filed September 24,
2010 (“Spec.”), the Final Office Action mailed November 17, 2014 (“Final
Act.”), the Appeal Brief filed April 16, 2015 (“App. Br.”), and the
Examiner’s Answer mailed October 19, 2015 (“Ans.”).
2 Appellants identify the real party in interest as SunPower Corporation.
App. Br. 3.
Appeal 2016-002254
Application 12/890,428
The claims are directed to a method of fabricating an emitter region of
a solar cell. Claim 1, reproduced below, is illustrative of the claims on
appeal.
1. A method of fabricating an emitter region of a solar cell, the
method comprising:
forming, in a furnace, a tunnel oxide layer on a surface of a
substrate, the forming comprising heating the substrate in
the furnace at a temperature of approximately, 900 degrees
Celsius at a pressure of approximately 500 mTorr for
approximately 3 minutes in an atmosphere of oxygen to
provide the tunnel oxide layer having a thickness of
approximately 1.5 nanometers; and, without removing the
substrate from the furnace,
forming an amorphous layer on the tunnel oxide layer;
doping the amorphous layer to provide a first region
comprising N-type dopants and a second region
comprising P-type dopants; and, subsequently,
heating the amorphous layer to provide a polycrystalline layer
comprising an N-type-doped region and a P-type-doped
region.
App. Br. 11 (Appendix A: Claims).
Independent claim 24 recites a method of fabricating an emitter region
of a solar cell similar to claim 1. See id. at 12—13.
Appellants argue the claims as a group, of which claim 1 above is
representative. See id. at 6—9. Appellants have not presented separate
arguments specifically directed to independent claim 24 or the dependent
claims under rejection. Id. As a consequence, dependent claims 2, 7, 8, 23,
25, and 26 will stand or fall with their parent independent claims as
represented by claim 1.
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Appeal 2016-002254
Application 12/890,428
DISCUSSION
Appellants request review of the rejection of claims 1, 2, 7, 8, and 23—
26 under 35 U.S.C. § 103(a) as unpatentable over Swanson (US 7,468,485
Bl, issued December 23, 2008) (hereinafter “Swanson”) in view of
Bergemont et al. (US 5,566,044, issued October 15, 1996) (hereinafter
“Bergemont”), Hatalis et al., “Large grain polycrystalline silicon by low
temperature annealing of low pressure chemical vapor deposited amorphous
silicon films,” 63 J. Appl. Phys. 2260—2266 (1988) (hereinafter “Hatalis”),
Green et al., “Understanding the Limits of Ultrathin Si02 and Si-O-N Gate
Dielectrics for Sub-50 nm CMOS,” 48 Microelectronic Engineering 25—30
(1999) (hereinafter “Green”), and Bierhals et al., “Improved understanding
of thermally activated structural changes in Al/SiOx/p-Si tunnel diodes by
means of infrared spectroscopy,” 83 J. Appl. Phys. 1371—1378 (1998)
(hereinafter “Bierhals”) from the Examiner’s Final Office Action. Final Act.
3—13; Ans. 3.
We review the appealed rejections for error based upon the issues
identified by appellants and in light of the arguments and evidence produced
thereon. Cf. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010)
(precedential) (cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed.
Cir. 2011) (“it has long been the Board’s practice to require an applicant to
identify the alleged error in the examiner’s rejections”)). After considering
the evidence presented in this Appeal and each of Appellants’ contentions,
we are not persuaded that Appellants identify reversible error. Thus, we
affirm the Examiner’s rejections for the reasons expressed in the Final
Office Action, the Answer, and below.
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Appeal 2016-002254
Application 12/890,428
The Examiner finds, and Appellants do not dispute that, Swanson
discloses a method of fabricating an emitter region of a solar cell that
includes forming a tunnel oxide on the surface of a substrate by ozone bath
oxidation or another means, forming a polysilicon layer on the tunnel oxide,
and doping the polysilicon layer to provide a second p-type region and a first
n-type region, but fails to teach the tunnel oxide formed in a furnace by
oxidation, and forming an amorphous silicon layer on the tunnel oxide layer
as required by claim 1. Final Act. 4 (citing Swanson 3:35—67, 4:1—15, and
4:55—67). The Examiner finds, and Appellants do not dispute that, it was
well-known, as evidenced by Bergemont, to form a tunnel oxide layer using
thermal oxidation in the same furnace or reaction chamber used to
subsequently deposit a silicon layer using vapor deposition. See Final Act. 4
(citing Bergemont 4:40-48); see also Ans. 13. The Examiner determines
that one of ordinary skill in the art would have been motivated to perform
thermal oxidation in the same process chamber or furnace used to
subsequently deposit a silicon layer, as taught by Bergemont, to form the
tunnel oxide layer in Swanson’s solar cell, and the results would have been
predictable. Final Act. 4; Ans. 13.
The Examiner acknowledges that the Swanson’s method, as modified
by Bergemont, fails to teach or suggest the temperature or pressure
conditions of the thermal oxidation step to form the tunnel oxide. Final
Act. 6. The Examiner, however, finds that temperature, pressure, and time
affect the growth rate and final thickness of the tunnel oxide, as evidenced
by Green and Beirhals, and thus are result-effective variables. Final Act. 6
(citing Green 26 (12) — 27 (13); Fig. 4, and Beirhals 1371 (11) and 1372
(H 3 4); Ans. 14. The Examiner determines that it would have been within
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Application 12/890,428
the skill of the ordinary artisan to “optimize the time, temperature, and
pressure of the oxidation step for growing the tunnel oxide within the scope
of the present claims so as to produce desired end results.” Final Act. 7.
Appellants argue that
Swanson does not disclose that its’ process for forming a tunnel
oxide layer, using an ozone bath, which is a wet chemical
process, “could be replaced with a . . . fabrication that requires .
. . (1) [forming] ... a thermal oxide [layer] in a furnace (which
is a dry growth process), (2) [forming the tunnel oxide layer] in
the same furnace as used to deposit a silicon layer, and
(3) [forming the tunnel oxide layer] in the same surface used to
subsequently form a silicon layer without removing the substrate
[from the furnace.”]
App. Br. 8 (emphasis omitted). Appellants further argue that “there is no
indication in Bergemont. . . that the [disclosure] of Bergemont. . . could be
understood to somehow be applied as a substitute for the process of
Swanson. Id.
Appellants’ arguments are not persuasive of reversible error in the
Examiner’s rejection. Appellants do not dispute the Examiner’s findings
with respect to Swanson or Bergemont individually. See App. Br. 6—9. A
preponderance of the evidence supports the Examiner’s reason to combine
Swanson and Bergemont because the proposed combination is nothing more
than the predictable use of prior art elements according to their established
functions. See KSRInt’l Co. v. Teleflex Inc., 550 U.S. 398, 417 (2007) (In
assessing the obviousness of claims to a combination of prior art elements,
the question to be asked is “whether the improvement is more than the
predictable use of prior art elements according to their established
functions.”). Appellants have not identified an error in the Examiner’s
reasoning and we find none.
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Application 12/890,428
Appellants argue that “[tjhere is no indication in Green of any
applicability to the solar industry.” App. Br. 8. Appellants also argue “there
is no indication that the processing parameters of Green and Bierhals could
even be combined to suggest processing parameters for a tunnel dielectric
for a solar cell.” Id. at 8—9. Appellants further argue that “even upon
combining the disclosures of Green and Bierhals . . . the [] claimed feature
would not be achieved.” Id. at 8.
Appellants’ arguments are not persuasive of reversible error in the
Examiner’s rejection. “A recognition in the prior art that a property is
affected by the variable is sufficient to find the variable result-effective.” In
re Applied Materials, Inc., 692 F.3d 1289, 1297 (Fed. Cir. 2012). The
portions of Green and Bierhals cited by the Examiner reasonably support the
finding that the temperature and pressure of the furnace used for forming the
tunnel oxide layer (e.g., a silicon oxide layer), as well as the time of growth
of the tunnel oxide layer in the furnace, are result effective variables. Final
Act. 6—7; Ans. 14. Appellants neither contest this finding or present
sufficient evidence that the claimed parameters for forming the tunnel oxide
layer—temperature and pressure of the furnace and the time of growth of the
tunnel oxide layer in the furnace—are critical, for example by showing that
the parameters achieve unexpected results. In re Aller, 220 F.2d 454, 456
(CCPA 1955). In fact, as the Examiner points out, Appellants’ Specification
discloses that a tunnel oxide layer having a thickness of approximately
1.5 nanometers may be formed in a furnace heated at a temperature of
approximately 565 degrees Celsius, at a pressure of approximately 300 Torr,
for approximately 60 minutes in an atmosphere of oxygen. Spec. 125;
Ans. 14. This disclosure is evidence that the claimed parameters at which
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Application 12/890,428
the furnace is operated (temperature, pressure, and time) are not critical and
do not produce any new or unexpected result. See Applied Materials, 692
F.3d at 1297 (“The outcome of optimizing a result-effective variable may
still be patentable if the claimed ranges are ‘critical’ and ‘produce a new and
unexpected result which is different in kind and not merely in degree from
the results of the prior art.”’ (internal citations omitted)).
For the reasons stated in the Final Action, Answer, and above,
Appellants fail to identify a reversible error in the § 103 rejection of
claims 1, 2, 7, 8, and 23—26.
DECISION
For the above reasons, the Examiner’s rejection of claims 1, 2, 7, 8,
and 23—26 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).
AFFIRMED
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