Ex parte Edward D. Nowak

Board of Patent Appeals and Interferences

Dec 10, 1997

08145268 (B.P.A.I. Dec. 10, 1997)

Application for patent filed October 29, 1993.1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered
today (1) was not written for publication in a law
journal and (2) is not binding precedent of the Board.
Paper No. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte EDWARD D. NOWAK
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Appeal No. 96-0348
Application 08/145,2681
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ON BRIEF
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Before URYNOWICZ, SOFOCLEOUS and DOWNEY, Administrative Patent
Judges.
DOWNEY, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from the final
rejection of claims 1, 3, 7 and 9, all the claims remaining in
this application.
The subject matter on appeal is directed to a heat sink for
semiconductor on insulator (SOI) circuits using a polysilicon
conductive pillar. The conductive pillar, which is physically in
Appeal No. 96-0348
Application 08/145,268
2
contact with the base of the bonded SOI wafer, is formed of doped
polysilicon, which doping by out-diffusion serves to electrically
insulate the conductive pillar from the base.
Appellant groups claims 1 and 3, and 7 and 9 and separately
argues the two groups. (Brief, page 3). 37 CFR § 1.192(c)(7).
Accordingly, we limit our consideration to claims 1 and 7, the
only independent claims, in considering the rejection of the
claims. Claims 1 and 7 read as follows:
1. In an integrated circuit, a heat sink comprising:
a conductive pillar which extends from a top of a
bonded semiconductor on insulator (SOI) wafer through
an isolation region of the bonded SOI wafer and is in
physical contact with a base of the bonded SOI wafer,
the base of the bonded SOI wafer being located below
the isolation region of the bonded SOI wafer, wherein
the conductive pillar comprises doped polysilicon,
doping for the polysilicon out-diffusing from the
polysilicon into the base, thereby electrically
insulating the conductive pillar from the base.

7. A heat sink formed on a bonded semiconductor on
insulator (SOI) wafer, the heat sink comprising:
conductive material in a trench, the trench extending
from a top of the bonded SOI wafer through an isolation
region of the bonded SOI wafer to a base of the bonded
SOI wafer, the base of the bonded SOI wafer being
located below the isolation region of the bonded SOI
wafer wherein the conductive extends from the top of
the bonded SOI wafer through the isolation region of
the bonded SOI wafer and is in physical contact with
but is electrically isolated from the base of the
bonded SOI wafer, the conductive material comprising
doped poly silicon, doping for the polysilicon out-
diffusing from the polysilicon into the base, thereby
electrically insulating the conductive material from
the base.
Appeal No. 96-0348
Application 08/145,268
3
The sole reference relied upon by the examiner is:
Tashiro 5,241,211 Aug. 31, 1993
Claims 1, 3, 7, and 9 stand rejected over Tashiro under
35 U.S.C. § 103. On this record, we reverse this rejection.
Opinion
Tashiro teaches a integrated circuit with a heat sink which
contains a thermally conductive polycrystalline silicon pillar
(234) extending from the top of a bonded SOI wafer through an
isolation layer (See Figure 2c). The pillar may also be silicon
carbide (235) (Figures 5 and 6). In either embodiment, the
pillar is electrically isolated by an oxide layer (233) which
surrounds the pillar.
The examiner recognizes that Tashiro does not show doping
for the polysilicon pillar but he asserts that it would have been
obvious to one of ordinary skill in the art to have doped the
polysilicon pillar of Tashiro "since it is well known in the art
to dope polysilicon and [such] does not change or effect thermal
conductivity." We cannot agree with the examiner's assertions.
The burden of establishing a prima facie case of obviousness
lies with the Patent and Trademark Office. In re Warner, 379
F.2d 1011, 1017, 154 USPQ 173, 178 (CCPA 1967). In order to
establish obviousness it is necessary to ascertain whether the
Appeal No. 96-0348
Application 08/145,268
4
reference teachings would appear to be sufficient for one of
ordinary skill in the relevant art having the reference before
him to make the proposed substitution, combination or
modification.
As is evident by the examiner’s admission, Tashiro does not
describe or suggest the doping of the polysilicon pillar.
Rather the examiner has asked us, without the production of any
evidence, to take notice of the existence and truth of the
examiner's assertion that "it is well known in the art to dope
polysilicon and that does not change or effect thermal
conductivity" and thereafter to find that it would have been
obvious to dope the conductive pillar of Tashiro. We decline to
take such notice, where as here, the facts requested to be
noticed are not of the type our reviewing court indicated to be
proper for facts to be judicially noticed. See In re Boon, 439
F.2d 724, 727, 169 USPQ 231, 234 (CCPA 1971); citing In re
Ahlert, 424 F.2d 1088, 1091, 165 USPQ 418, 420-21 (CCPA 1970).
The decision of the examiner is reversed.
REVERSED
Appeal No. 96-0348
Application 08/145,268
5
STANLEY M. URYNOWICZ, JR. )
Administrative Patent Judge )
)
)BOARD OF PATENT
MICHAEL SOFOCLEOUS )
Administrative Patent Judge ) APPEALS AND
)
)INTERFERENCES
MARY F. DOWNEY )
Administrative Patent Judge )
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