UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/613,041 09/13/2012
49267 7590 05/31/2018
TUTUNJIAN & BITETTO, P.C.
401 Broadhollow Road, Suite 402
Melville, NY 11747
FIRST NAMED INVENTOR
AHMED ABOU-KANDIL
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
YOR920110187US2 (409 5565
CON)
EXAMINER
MARTIN, BETHANY LAMBRIGHT
ART UNIT PAPER NUMBER
1721
NOTIFICATION DATE DELIVERY MODE
05/31/2018 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
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PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte AHMED ABOU-KANDIL,
KEITH E. FOGEL, AUGUSTIN J. HONG,
JEEHWAN KIM, and DEVENDRA K. SADANA
Appeal2017-006858
Application 13/613,041
Technology Center 1700
Before ADRIENE LEPIANE HANLON, A VEL YN M. ROSS, and
SHELDON M. McGEE, Administrative Patent Judges.
HANLON, Administrative Patent Judge.
DECISION ON APPEAL
A. STATEMENT OF THE CASE
The Appellants filed an appeal under 35 U.S.C. § 134(a) from an Examiner's
decision finally rejecting claims 1-3, 5, 7-12, and 14. We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM.
Representative claim 1 is reproduced below from the Claims Appendix of
the Appeal Brief dated November 23, 2015 ("Br."). The limitations at issue are
italicized.
1. A photovoltaic device, comprising:
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Application 13/613,041
a light-absorbing semiconductor structure including a first
doped layer including a first conductivity type dopant of a p-type
conductivity, a first intrinsic layer of amorphous silicon and a first
tunnel junction layer having a second conductivity type dopant of an
n-type conductivity and composed of microcrystalline silicon;
an interface grown using a hydrogen plasma from the
amorphous silicon of the first intrinsic layer, the inteiface being
positioned between the first intrinsic layer and the first tunnel junction
layer, the interface being a seed layer of silicon crystals grown from
the amorphous silicon to enable microcrystalline growth of the first
tunnel junction layer and a second tunnel junction layer, the seed
layer being in direct contact with the first tunnel junction layer and
the seed layer being in direct contact with the first intrinsic layer so
that the first tunnel junction layer is in contact with the first intrinsic
layer through the seed layer, wherein the first doped layer, the first
intrinsic layer, and the first tunnel junction layer provide a first cell
having a first bandgap, wherein the first cell is a p/i/n cell; and
a second cell present on the first cell comprising the second
tunnel junction layer and a second intrinsic layer including a second
amorphous material phase that is present on the second tunnel
junction layer, wherein the second cell has a second bandgap that is
less than the first bandgap.
App. Br. 27.
The claims on appeal stand rejected as follows:
(1) claims 1-3 and 7 under 35 U.S.C. § 103(a) as unpatentable over Choi
350 1 in view of Choi 8782 and Sawada, 3 as evidenced by Pemet; 4
1 US 2008/0173350 Al, published July 24, 2008 to Choi et al. ("Choi 350").
2 US 2009/0142878 Al, published June 4, 2009 to Choi et al. ("Choi 878").
3 US 2009/0165853 Al, published July 2, 2009 to Sawada et al. ("Sawada").
4 P. Pemet et al., Growth of Thin
µc-Si:H on Intrinsic a-Si:Hfor Solar
Cells Application, 452 Materials Research Soc'y 889-894 (1997) ("Pemet").
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Application 13/613,041
(2) claim 5 under 35 U.S.C. § 103(a) as unpatentable over Choi 350 in
view of Choi 878 and Sawada, as evidenced by Pemet, and further in view of
Yasuno· 5
'
(3) claim 8 under 35 U.S.C. § 103(a) as unpatentable over Choi 350 in
view of Choi 878 and Sawada, as evidenced by Pemet, and further in view of
Sichanugrist; 6
(4) claims 9-11 and 14 under 35 U.S.C. § 103(a) as unpatentable over
Choi 350 in view of Choi 878, Sawada, and Sichanugrist, as evidenced by Pemet;
and
(5) claim 12 under 35 U.S.C. § 103(a) as unpatentable over Choi 350 in
view of Choi 878, Sawada, and Sichanugrist, as evidenced by Pemet, and further in
view of Yasuno.
The rejections are sustained for the reasons presented in the Examiner's
Answer dated May 4, 2016 ("Ans."). We add the following for emphasis.
B. ISSUE
The dispositive issue on appeal is whether the Examiner reversibly erred in
concluding that it would have been obvious to one of ordinary skill in the art to
grow a seed layer of silicon crystals from the amorphous silicon of the first
intrinsic layer disclosed in Choi 350 using a hydrogen plasma based on the
teachings of Choi 878, as evidenced by Pemet.
C. DISCUSSION
The Examiner finds Choi 3 50 discloses a tandem solar cell structure
comprising, inter alia, a first semiconductor subcell, corresponding to the claimed
5 US 2003/0015234 Al, published January 23, 2003 to Yasuno ("Yasuno").
6 US 4,790,883, issued December 13, 1988 to Sichanugrist et al. ("Sichanugrist").
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Application 13/613,041
"light-absorbing semiconductor structure," comprising a first p-type silicon layer, a
first intrinsic amorphous silicon layer, and a first n-type microcrystalline silicon
layer. Ans. 4; see also Ans. 12.
The Examiner finds Choi 350 does not disclose the following limitation
recited in claim 1 :
an interface grown using a hydrogen plasma from the amorphous
silicon of the first intrinsic layer, the interface being positioned
between the first intrinsic layer and the first tunnel junction layer, the
interface being a seed layer of silicon crystals grown from the
amorphous silicon to enable microcrystalline growth of the first tunnel
junction layer and a second tunnel junction layer.
Ans. 5; see also Ans. 13-14.
The Examiner finds Choi 878 discloses
a method of forming a tandem solar cell wherein after the deposition
of an amorphous silicon layer but prior to the deposition of a
microcrystalline silicon layer, the amorphous silicon layer is treated
with hydrogen plasma, forming seed sites of microcrystalline silicon
in order to help improve the deposition of the subsequent
microcrystalline silicon layer thereon.
Ans. 5---6 (citing Choi 878, at i-f 31 ); see also Ans. 14.
The Examiner concludes that it would have been obvious to one of ordinary
skill in the art
to treat the intrinsic amorphous silicon layer disclosed by Choi [350]
with a hydrogen plasma treatment which would result in the formation
of seeds on the surface of the intrinsic amorphous [layer] in Choi' s
solar cell, as taught by Choi '878, in order to improve deposition of
the first microcrystalline silicon tunnel junction layer which is
deposited onto the intrinsic amorphous silicon layer and seeds.
Ans. 6; see also Ans. 14.
Similar to Choi 350, Choi 878 discloses a tandem junction solar cell. Choi
878, at i-f 18. The first p/i/njunction in Choi 878 comprises a p-doped silicon layer,
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Application 13/613,041
an intrinsic amorphous silicon layer, and an n-doped silicon layer. Choi 878, at
i-f 21. In contrast to Choi 350, however, the Appellants argue that Choi 878
includes two amorphous layers, i.e., an intrinsic amorphous silicon layer and an n-
type doped amorphous silicon layer wherein then-type amorphous silicon layer is
between the intrinsic amorphous silicon layer and the n-type microcrystalline
layer. Br. 11. The Appellants argue that the n-type amorphous silicon layer, not
the intrinsic amorphous silicon layer as in the Appellants' claimed invention, is
treated with a plasma to increase nucleation for the later deposited n-type
microcrystalline layer. Br. 11. Therefore, the Appellants argue that one of
ordinary skill in the art would not have been motivated to plasma treat the intrinsic
amorphous silicon layer of Choi 350 as proposed by the Examiner. Br. 18.
In response, the Examiner explains:
Choi '878 is relied upon simply as a general teaching that hydrogen
plasma treatment of an amorphous silicon layer results in seed
formation along a surface thereof for improved deposition of a
microcrystalline silicon layer thereon because a portion of the
amorphous silicon layer is converted in microcrystalline silicon seed
sites (Choi '878 [0031 ][7J).
Ans. 23 (emphasis omitted).
In that regard, Choi 878 discloses:
While the discussion herein, mainly discusses providing a
plasma treatment process between the deposition of an n-doped
amorphous silicon layer and an n-doped microcrystalline layer this
process configuration is not intended to [be] limiting as to the scope of
the invention described herein. It is thus noted that prior to each of
7 Paragraph 31 of Choi 878 discloses, in relevant part:
[I]t is believed that the plasma treatment helps to convert at least a
portion of the n-doped amorphous silicon layer into n-doped
microcrystalline silicon. This n-doped microcrystalline silicon acts as
a seed layer improving n-doped microcrystalline deposition thereon.
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Application 13/613,041
the deposition steps for each of the layers in the first p-i-njunction ...
and the second p-i-njunction ... , including n-type, intrinsic type and
p-type silicon containing layers, an optional plasma treatment process
may be peiformed. As noted above the plasma treatment is believed
to be especially advantageous when used between an amorphous
layer deposition step and a microcrystalline layer deposition step to
promote nucleation of the microcrystalline layer.
Choi 878, at i-f 36 (emphasis added).
Thus, we find that one of ordinary skill in the art would have understood that
the disclosure in Choi 878 is not limited to plasma treating an n-type doped
amorphous silicon layer, as argued by the Appellants, but rather teaches plasma
treating amorphous layers in general, including the intrinsic amorphous silicon
layer disclosed in Choi 350, to promote nucleation of a microcrystalline layer. Our
finding is consistent with the Examiner's factual findings as to Pemet. See, e.g.,
Ans. 27 (finding that Pemet shows "hydrogen plasma treatment of an intrinsic
amorphous silicon layer for nucleation to assist in the deposition of a
microcrystalline layer thereon"); see also Pemet 893 (disclosing that plasma
exposure, including hydrogen plasma exposure, "generally leads to more
favourable nucleation conditions for doped µc-Si:H, somewhat independently of
the gas and the substrate I underlying layer involved").
In sum, a preponderance of the evidence supports the Examiner's conclusion
that it would have been obvious to one of ordinary skill in the art to grow a seed
layer of silicon crystals from the amorphous silicon of the first intrinsic layer
disclosed in Choi 350 using a hydrogen plasma based on the teachings of Choi
878, as evidenced by Pemet. Therefore, the§ 103(a) rejections on appeal are
sustained.
D. DECISION
The Examiner's decision is affirmed.
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Application 13/613,041
No time period for taking any subsequent action in connection with this
appeal may be extended under 3 7 C.F .R. § 1.13 6( a)( 1 )(iv).
AFFIRMED
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