Ex Parte Haeckl et al

Patent Trial and Appeal Board

Aug 15, 2017

13533441 (P.T.A.B. Aug. 15, 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.
13/533,441 06/26/2012 Walter HAECKL W1154/20054 4492
3000 7590
CAESAR RIVISE, PC
7 Penn Center, 12th Floor
1635 Market Street
Philadelphia, PA 19103-2212
EXAMINER
GAMBETTA, KELLY M
ART UNIT PAPER NUMBER
1715
NOTIFICATION DATE DELIVERY MODE
08/17/2017 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):
patents @ crbcp .com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte WALTER HAECKL, BARBARA MUELLER and
ROBERT RING1
Appeal 2015-008074
Application 13/533,441
Technology Center 1700
Before BRADLEY R. GARRIS, JEFFREY B. ROBERTSON, and
JENNIFER R. GUPTA, Administrative Patent Judges.
GARRIS, Administrative Patent Judge.
DECISION ON APPEAL
Pursuant to 35 U.S.C. § 134, Appellants appeal from the Examiner’s
rejection under 35 U.S.C. § 103(a) of claims 5—12 and 14—19 as
unpatentable over Sofin (US 2008/0286550 Al, published Nov. 20, 2008) in
view of Ingle (US 4,526,769, issued Jul. 2, 1985) and the admitted prior art
described in the Specification (Spec. 2-4). We have jurisdiction under
35 U.S.C. §6.
1 Wacker Chemie AG, Muenchen (DE) is identified as the real party in
interest. Br. 2.
Appeal 2015-008074
Application 13/533,441
We AFFIRM.
Appellants claim a process for producing polysilicon comprising:
deposition of polycrystalline silicon in a deposition reactor 11 with a
reaction gas containing a silicon-containing component comprising
trichlorosilane and having a molar saturation of at least 31%; treating an
offgas from the deposition with a cooling apparatus 12, a distillation
apparatus 14, and an adsorption unit 13 to obtain, inter alia, a first stream
110 which contains hydrogen; and obtaining, during a regeneration of the
adsorption unit with purge gas 111, a second stream 113 which contains
silicon tetrachloride and is supplied to a converter 15 for conversion of
silicon tetrachloride to trichlorosilane (sole independent claim 5, Fig. 1).
A copy of representative claim 5, taken from the Claims Appendix of
the Appeal Brief, appears below.
5. A process for producing polysilicon, comprising
a) deposition of polycrystalline silicon on filaments in a
deposition reactor with a reaction gas containing a silicon-containing
component comprising trichlorosilane, and hydrogen, wherein a molar
saturation of the silicon-containing component based on
hydrogen is at least 31%;
b) feeding an offgas from the deposition into an apparatus for
cooling the offgas,
i) wherein components of the offgas which condense as a result
of the cooling and contain silicon tetrachloride are conducted to an
apparatus which enables distillative purification of a condensate, and
ii) non-condensing components which do not condense in a course
of cooling are conducted to an adsorption or desorption unit;
c) obtaining a first stream of the non-condensing components
which has been purified by adsorption and contains hydrogen; and
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Application 13/533,441
d) obtaining, during a regeneration of the adsorption unit by
desorption and purging with purge gas, a second stream of the non­
condensing components, which contains silicon tetrachloride and is
supplied to a converter for conversion of silicon tetrachloride to
trichlorosilane.
Appellants do not present separate arguments specifically directed to
the dependent claims under rejection (see Br. 9—17). Therefore, the
dependent claims will stand or fall with their parent independent claim 5.
We will sustain the Examiner’s rejection for the reasons well stated in
the Final Action and Answer. The following comments are added for
emphasis.
In rejecting claim 5, the Examiner finds that Sofin teaches deposition
of polycrystalline silicon via a silicon-containing component having a molar
saturation of at least 31% as claimed but does not teach a recycling process
having the claimed steps of treating an offgas from the deposition (Final
Action 4). With regard to this deficiency, the Examiner finds that Ingle
teaches an offgas recycling process (i.e., wherein offgas from a
polycrystalline silicon deposition reactor is treated with a cooling apparatus,
a distillation apparatus, an adsorption unit, and a reactor/converter for
converting silicon tetrachloride to trichlorosilane) and concludes that it
would have been obvious to provide Sofin with such a recycling process to
save costs and materials (id.). The Examiner additionally finds that, while
Ingle does not teach regenerating the adsorption unit to obtain a stream
which is supplied to the reactor/converter as claimed, the admitted prior art
discloses regenerating an adsorption unit and sending a stream resulting
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Appeal 2015-008074
Application 13/533,441
therefrom to an apparatus for converting silicon tetrachloride to
trichlorosilane (id. at 4—5). The Examiner concludes that it would have been
obvious to provide the Sofin/Ingle process with the regenerating and
converting steps taught by the admitted prior art (id. at 5).
Appellants argue the Examiner erred in finding that Sofin teaches the
deposition step of claim 5 having the claimed molar saturation of at least
31% (Br. 10). According to Appellants, “Sofin relates to a polysilicon
process starting with a low molar concentration, ‘at most 30%, preferably 20
to 25%’ and slowly increasing this concentration throughout the process”
(id., citing Sofin || 52—53 (emphasis added by Appellants)). Appellants
further argue that “Sofin teaches away from [the] claimed ‘at least 31%,’
stating about the starting silicon-containing gas: ‘[t]he molar fraction of the
chlorosilane compounds, preferably trichlorosilane, is then at most 30%’”
(Br. 16, citing Sofin | 52 (emphasis added by Appellants)).
The Examiner responds by finding that Sofin’s deposition process,
while beginning with a molar concentration of at most 30%, ultimately
raises the concentration to 35—60% (Ans. 6, citing Sofin 147 (“at the latest
after a rod diameter of 120 mm has been reached,. . . reducing the amount
of hydrogen introduced by nozzles such that the molar fraction of the
chlorosilanes in the feed gas is increased to at least 35%, but at most 60%”);
see also id. at 9). In this regard, the Examiner determines that the broadest
reasonable interpretation of claim 5 includes a molar saturation of at least
31% at any point in the deposition process, thereby encompassing Sofin’s
ultimate range of 35—60% (id. at 5—6). Significantly, Appellants do not
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Application 13/533,441
dispute the Examiner’s finding or claim interpretation (i.e., no Reply Brief
has been filed).
Appellants also contest the Examiner’s above finding that Ingle
discloses a reactor/converter for conversion of silicon tetrachloride to
trichlorosilane (see, e.g., Ingle Fig. 2 element 10, col. 6,11. 56—61) in
accordance with the “converter” limitation of claim 5 (Br. 15—16). In
particular, Appellants contend that “Ingle’s ‘co[n]version’ is not the same
process utilized by the claimed ‘converter’ in step d)” (id. at 15). As
explanation for this contention, Appellants state that “the conversion
apparatus, ‘converter,’ as claimed and detailed in the specification [and in
Figure 6] specifically refers to an apparatus [differing in various respects
from Ingle’s reactor]” (id. at 15—16).
In response, the Examiner determines that the broadest reasonable
interpretation of the claimed converter is “a device [such as Ingle’s
reactor 10] that converts silicon tetrachloride to trichlorosilane” (Ans. 7) and
that the differences identified by Appellants between their disclosed
converter and Ingle’s reactor are not recited in claim 5 (id. at 7—8). As
above, Appellants do not respond to and therefore do not show error in the
Examiner’s determinations.
Finally, Appellants argue that the Examiner’s obviousness conclusion
is erroneous because the claimed molar saturation of at least 31% yields
surprising benefits involving decreased contamination in the deposition
circuit and a cost benefit resulting from controlling HC1 concentration
(Br. 13-14).
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Application 13/533,441
The Examiner rebuts Appellants’ argument by pointing out that: (1)
any benefit or advantage of the claimed molar saturation would flow
naturally from following the suggestion of the prior art because Sofin
explicitly teaches values encompassed by the claimed range, thereby
evincing obviousness (Ans. 6—7, citing Ex parte Obiaya, 227 U.S.P.Q. 58,
60 (BPAI 1985)); (2) claim 5 contains no recitation involving deposition
circuit/contamination or HC1 concentration/control (Ans. 7); and (3)
Appellants have submitted no proof that claim 5 is commensurate in scope
with a process yielding the above argued benefits {id.). The Examiner’s
points are well taken. Moreover, because no Reply Brief has been filed,
none of these points have been challenged by Appellants in the record of this
appeal.
For the reasons given by the Examiner and emphasized above, we
sustain the § 103 rejection of claims 5—12 and 14—19 as unpatentable over
Sofin in view of Ingle and the admitted prior art.
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)(l)(iv).
AFFIRMED
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