Ex Parte Cornfeld

Patent Trial and Appeal Board

Apr 15, 2015

12544001 (P.T.A.B. Apr. 15, 2015)

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.
12/544,001 08/19/2009 Arthur Cornfeld 9015/6009-082 8482
128940 7590 04/15/2015
SolAero Technologies Corp.
10420 Research Road SE
Albuquerque, NM 87123
EXAMINER
MCCONNELL, MARLA D
ART UNIT PAPER NUMBER
1758
MAIL DATE DELIVERY MODE
04/15/2015 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 ARTHUR CORNFELD
__________

Appeal 2013-006249
Application 12/544,001
Technology Center 1700
____________

Before BRADLEY R. GARRIS, MICHAEL P. COLAIANNI, and
SHEILA F. McSHANE, Administrative Patent Judges.

COLAIANNI, Administrative Patent Judge.

DECISION ON APPEAL
Appellant appeals under 35 U.S.C. § 134 from the final rejection of
claims 1–3, 7–17, and 19–21. We have jurisdiction over the appeal pursuant
to 35 U.S.C. § 6(b).
We AFFIRM.
Appellant’s invention is directed to multijunction solar cells based on
III-V semiconductor compounds including a metamorphic layer (Spec. ¶
25).
Claim 1 is illustrative:
1. A multijunction semiconductor solar cell comprising:
an upper first solar subcell having a first band gap;
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Application 12/544,001

a middle second solar subcell adjacent to said first solar
subcell and having a second band gap smaller than said first
band gap, and having a base layer and an emitter layer;
a graded interlayer adjacent to said second solar subcell,
said graded interlayer having a third band gap greater than said
second band gap;
a lower third solar subcell adjacent to said graded
interlayer, said lower third solar subcell composed of an
InGaAs base layer and an adjacent InGaP emitter layer that is
lattice matched to the adjacent base layer, said lower third
subcell having a fourth band gap smaller than said second band
gap such that the third subcell is lattice mismatched with
respect to the second subcell; and
a metal electrode layer comprising molybdenum
deposited on the lower subcell and having a coefficient of
thermal expansion that has a value within 50% of the
coefficient of thermal expansion of the directly adjacent
semiconductor material.

Appellant appeals the following rejections:
1. Claims 1–3, 8, 9, 11–14, 16, and 17 are rejected under 35 U.S.C. §
103(a) as being unpatentable over Wanlass (US 2006/0144435,
published Jul. 6, 2006 ) in view of Jeng (The reflectivity of Mo/Ag/Au
ohmic contacts on p-type GaN for flip-chip light-emitting diode
(FCLED) applications, APPLIED SURFACE SCIENCE 254, 4479–4482
(2008)) as evidenced by Kagawa (US 4,906,583, issued Mar. 6, 1990)
and the CRC Handbook of Chemistry and Physics, 91st Ed. (c) 2010–
2011 (hereinafter CRC).
2. Claims 1–3, 7, 9, 11, 13–17, 19, and 21 are rejected under 35 U.S.C. §
103(a) as being unpatentable over Cornfeld (US 2007/0277873 A1,
published Dec. 6, 2007) in view of Wanlass, Miller (V/AI/V/Ag Ohmic
contacts to n-AIGaN/GaN heterostructures with a thin GaN cap,
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APPLIED PHYSICS LETTERS 91, 012103 (2007) ) and Masuda (High
Performance InP/InGaAs HBTs for 40-Gb/s Optical Transmission
ICs, IEICE TRANS. ELECTRON., Vol. E82–C, No.3 (1999)) as evidenced
by Kagawa and the CRC.
3. Claim 10 is rejected under 35 U.S.C. § 103(a) as being unpatentable
over Cornfeld in view of Wanlass, Miller, and Masuda as evidenced
by Kagawa and the CRC and further in view of Barnett (US
4,677,250, issued Jun. 30, 1987) as evidenced by Takeda (US
5,022,455, issued Jun. 11, 1991).
4. Claims 15 and 20 are rejected under 35 U.S.C. § 103(a) as being
unpatentable over Wanlass in view of Jeng as evidenced by Kagawa
and the CRC and further view of Cornfeld.

In the Appeal Brief, Appellant’s arguments focus on claim 1 only (Br.
4–14). Appellant raises new arguments against claims 10, 15, 19, and
20 for the first time in the Reply Brief (Reply Br. 1–7). Appellant
additionally argues and provides evidence for the first time against the
Examiner’s finding that the silver in Jeng’s molybdenum layer
provides a high reflectance to the metal layer (Reply Br. 7–9). These
arguments were not made in response to issues raised by the Examiner
for the first time in the Examiner’s Answer. Rather, the Final Action
mailed August 1, 2012, includes the same rejections copied in the
Examiner’s Answer. The Examiner in the “Response to Arguments”
section of the Answer merely responds to Appellant’s arguments
regarding the rejection of claim 1 made in the principal Brief (Ans.
33–51). Therefore, we shall not consider Appellant’s improperly
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raised new arguments and evidence included in the Reply Brief. See
37 C.F.R. 41.41(b)(1)(2) (2012); cf. Ex parte Borden, 93 USPQ2d
1473, 1474 (BPAI 2010) (informative). The rejection of independent
claims 19 and 20 and dependent claims 2, 3, 7-17, and 21 will stand or
fall with our analysis of the rejection of claim 1.

FINDINGS OF FACT AND ANALYSES
The Examiner’s findings and conclusions regarding Wanlass,
Cornfeld, Jeng, Masuda and Miller are located on pages 3–7 and 10–14 of
the Answer.
Appellant argues that none of the prior art relied upon by the
Examiner teaches or suggests a solution to the potential problem in
manufacturing solar cells identified by the Appellant (Br. 5, 7, 11).
Appellant contends that none of the prior art teaches or suggests the
importance of matching the coefficient of thermal expansion for associated
layers to that of the semiconductor body, while still maintaining appropriate
electrical conductivity and structural properties of the layers (Br. 5, 6, 11).
Appellant argues that the Examiner has not shown that there are a finite
number of predictable solutions for the potential problem in manufacturing
solar cells identified by the present inventor (Br. 7, 13).
Contrary to Appellant’s argument, the Examiner has provided a
reason for the substitution of Jeng’s molybdenum metal layer for Wanlass’
gold layer: to provide better reflectivity to the semiconductor (Ans. 6). The
Examiner finds and Appellant does not contest that Jeng and Wanlass each
teaches that a metal layer on the backside of the semiconductor with greater
reflectance is desirable (Ans. 6, 36–37).
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Similarly, the Examiner’s reason for modifying Cornfeld as modified
by Wanlass to have the molybdenum containing metal layer is to provide a
smooth (i.e., low surface roughness) electrode that prevents intermixing of
the semiconductors and the metals (Ans. 13). The Examiner bases this
rationale on the teachings of Masuda and Miller. Id.
The Examiner’s reason for modifying Wanlass and/or Cornfeld as
modified by Wanlass with the teachings of Jeng or Masuda and Miller,
respectively, need not be the same as Appellant’s reason for making the
modification. KSR Int’l Co. v. Teleflex Corp., 550 US 398, 420 (2007)
(“The question is not whether the combination was obvious to the patentee
but whether the combination was obvious to a person with ordinary skill in
the art. Under the correct analysis, any need or problem known in the field
of endeavor at the time of invention and addressed by the patent can provide
a reason for combining the elements in the manner claimed.”). Appellant’s
argument regarding the problem addressed by Appellant is not persuasive.
Contrary to Appellant’s argument regarding whether the applied prior
art shows a finite number of predictable solutions for the potential problems
in manufacturing solar cells, the Examiner’s rejection is based upon the
teachings of the applied references to make the substitution to address
reflectivity or surface roughness/intermixing of the semiconductors. The
Examiner’s rejection is also based upon the substitution of molybdenum as a
known functional equivalent metal (Ans. 14). Accordingly, the applied prior
art would have suggested the modification of Wanlass and/or Cornfeld as
found by the Examiner. Appellant’s argument does not address the
Examiner’s findings and conclusions in the stated rejection.
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Appellant argues that Jeng is directed to a flip-chip light emitting
diode (LED) that contains no teaching or suggestion of solar cells (Br. 7).
Appellant contends that Jeng’s LED consumes only a small area on a
semiconductor chip and it has many fewer layers than a solar cell (Br. 7).
Appellant argues that the solar cell requires a much larger horizontal area to
capture light and has many more layers than are present in a LED. Id.
Appellant argues that because of the solar cell’s size, manufacturing defects
may be a major issue for a solar cell, which would not be the case for a
much smaller LED (Br. 8). Appellant argues that Jeng’s molybdenum
electrode is merely to provide electrical contact for the LED whereas the
claimed metal layer covers the entire surface of the solar cell and may be
subjected to higher temperatures during manufacture. Id. Appellant
contends that one of ordinary skill in the art would not have looked to a LED
electrical contact layer as disclosed by Jeng to modify Wanlass and/or
Cornfeld (Br. 8–9).
Appellant’s arguments are directed to limitations not appearing the
claims. The Examiner properly finds that the Appellant’s arguments
regarding the size of a solar cell and the manufacturing defects that may
arise are directed to limitations not in the claims (Ans. 41). Claim 1 does not
recite a particular size of the solar cell or the particular number of layers that
comprise the solar cell. Appellant has not provided any evidence to
substantiate the mere attorney argument that a LED and a solar cell differ to
the argued extent. In re Schulze, 346 F.2d 600, 602 (CCPA 1965)
(“Argument in the brief does not take the place of evidence in the record”).
Moreover, the Examiner makes specific findings regarding how LEDs and
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solar cells are similar, which Appellant does not respond to or otherwise
show to be erroneous (Ans. 39; Reply Br. generally).
Regarding the rejections over Cornfeld in view of Wanlass, Masuda
and Miller, Appellant contends that Miller is directed to “high electron
mobility transistors (HEMTs)” and Masuda is directed to “heterojunction
bipolar transistors (HBTs)” (Br. 13). Appellant argues that neither Miller
nor Masuda is directed to solar cells and neither piece of prior art would
have taught problems concerning solar cells. Id.
The Examiner agrees that Miller and Masuda are not directed to solar
cells, but the Examiner finds that Miller and Masuda are directed to
semiconductor heterojunctions that are made of the same materials as the
photovoltaic cells of Wanlass and Cornfeld (Ans. 49). The Examiner finds
that Masuda’s and Miller’s device and Wanlass’ and Cornfeld’s device are
comprised of heterojunctions and are therefore similar devices (i.e., all are
III-V heterojunctions between two electrodes that generate an electrical
output in response to stimuli) (Ans. 49). The Examiner finds that Masuda
and Miller are in the same field of endeavor as Wanlass and Cornfeld.
The Examiner further finds that Wanlass, Cornfeld, Miller and
Masuda all provide layered contacts for the semiconductor devices, which
transport charge and thus are directed to solving the same problem as
Appellant (Ans. 49). The Examiner finds that the layered contact structure
solves the same problem and an ordinary artisan would have looked to
layered contacts of similar devices (III-V semiconductors), which solve the
same problem (charge transport) in order to modify III-V semiconductor
solar cells or other similar devices. Id. Appellant does not respond to or
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otherwise show error with the Examiner’s finding and thorough analysis that
Miller and Masuda are analogous art.
Appellant further argues that the Examiner has improperly focused on
the reflective property of the metal layer instead of addressing other various
structural properties of the metal layer in the rejection over Wanlass in view
of Jeng (Br. 9). Appellant contends that there are many high reflective metal
contact layers that would not have a coefficient of thermal expansion
substantially similar to that of the adjacent semiconductor. Id. Appellant
contends that the Examiner has not provided a sufficient rationale to
motivate one of skill in the art to select Jeng’s particular metal contact layer.
Id.
Appellant argues that the Examiner arbitrarily selected low surface
roughness and prevention of intermixing of the semiconductors and metals
while ignoring other important properties of the metal layer, such as
conductivity, structural properties, chemical properties, and thermal
properties in the rejection of Cornfeld in view of Wanlass, Masuda and
Miller (Br. 13). Appellant contends that there are many metal contact layers
that would have low surface roughness and /or prevent intermixing, but that
would not have a coefficient of thermal expansion substantially similar to
the adjacent semiconductor (Br. 14).
As noted above, the Examiner’s reason for modifying Wanlass to
have Jeng’s molybdenum-containing layer and Cornfeld as modified by
Wanlass to have Masuda’s or Miller’s molybdenum-container layer need not
be the same as Appellant’s reason. As found by the Examiner, Wanlass and
Jeng both teach using the metal layers for their reflective property. The
Examiner further finds that Cornfeld discloses a multilayered electrode,
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which both Miller and Masuda recognize as having problems with
intermixing and increased surface roughness without a molybdenum layer
(Ans. 46). The Examiner finds that Masuda discloses adding the
molybdenum layer decreases contact resistivity over electrodes that do not
contain the layer (Ans. 46). Accordingly, we agree with the Examiner that
there would have been reason for the ordinarily skilled artisan to make the
proposed modification.
Regarding the claimed coefficient of thermal expansion, the Examiner
makes specific findings that once Jeng’s molybdenum-containing layer is
substituted for Wanlass’ gold layer or Miller’s and Masuda’s molybdenum-
containing layer is substituted for Cornfeld’s metal layer as modified by
Wanlass, the resulting structure would have had inherently a coefficient of
thermal expansion that satisfies the claimed thermal expansion coefficient
range (i.e., a thermal expansion coefficient value within 50% of the
coefficient of thermal expansion of the directly adjacent semiconductor
material) (Ans. 6–7, 13–14, 43, 50–51). Specifically, the Examiner finds
that Jeng’s, Miller’s and Masuda’s molybdenum-containing layers have
thermal expansion coefficients that are within 50% of the thermal expansion
coefficient of the GaInAs semiconductor that is adjacent to the metal layer
(Ans. 6–7, 14). Appellant does not specifically contest or otherwise show
error with this finding of the Examiner.
On this record, we affirm all the Examiner’s § 103 rejections.

DECISION
The Examiner’s decision 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).

ORDER
AFFIRMED

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10