Ex Parte Cai et al

Board of Patent Appeals and Interferences

Jul 22, 2003

09733836 (B.P.A.I. Jul. 22, 2003)

The opinion in support of the decision being entered today was not written
for publication and is not binding precedent of the Board.
Paper No. 17
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte Jun Cai, Guang Ping Hua, Jun Song,
and
Keng Foo Lo
____________
Appeal No. 2002-2087
Application No. 09/733,836
____________
ON BRIEF
____________
Before OWENS, WALTZ, and PAWLIKOWSKI, Administrative Patent Judges.
WALTZ, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on an appeal from the primary examiner’s
final rejection of claims 9 through 16. Claims 1-8, which are the
only other claims pending in this application, stand withdrawn from
consideration by the examiner as drawn to a non-elected invention
(Brief, page 1). We have jurisdiction pursuant to 35 U.S.C. § 134.
According to appellants, the invention is directed to a
transistor structure for electrostatic discharge (ESD) protection
in an integrated circuit device where the semiconductor substrate
Appeal No. 2002-2087
Application No. 09/733,836
2
has source and drain diffusion regions over respective source and
drain wells, with a shallow trench isolation (STI) formed over and
into the substrate to separate the source and drain diffusion
regions and a portion of the source and drain wells, and source and
drain contact structures formed on and extending through the STI to
contact the source and drain diffusion regions (Brief, page 2).
Representative independent claim 9 is reproduced below:
9. An electrostatic discharge protection structure
comprising:
a semiconductor substrate, the semiconductor substrate having
source and drain diffusion regions, the semiconductor
substrate having respective source and drain wells under
the source and drain diffusion regions;
a shallow trench isolation formed over the semiconductor
substrate and into the semiconductor substrate to
separate the source and drain diffusion regions and a
portion of the source and drain wells; and
source and drain contact structures respectively formed on
the shallow trench isolation over the source and drain
diffusion regions and extending through the shallow
trench isolation to contact the source and drain
diffusion regions.
The examiner relies upon the following references as evidence
of obviousness:
Williams et al. (Williams) 5,545,909 Aug. 13, 1996
Lin et al. (Lin) 6,218,226 B1 Apr. 17, 2001
(filed Jan. 21, 2000)
Appeal No. 2002-2087
Application No. 09/733,836
1The final rejection of claims 9-16 under 35 U.S.C. § 103(a)
over Williams alone or in view of Lin has been withdrawn by the
examiner (Answer, page 2; Reply Brief, page 7).
3
Claims 9-16 stand rejected under 35 U.S.C. § 112, first
paragraph, “as containing subject matter which was not described in
the specification in such a way as to enable one skilled in the art
to which it pertains, or with which it is most nearly connected, to
make and/or use the invention.” Answer, page 3.
Claims 9-16 stand rejected under 35 U.S.C. § 112, second
paragraph, as being indefinite (Answer, page 4). Claims 9-16 also
stand rejected under 35 U.S.C. § 103(a) as unpatentable over Lin in
view of Williams (Answer, page 5).1
We reverse all of the examiner’s rejections on appeal
essentially for the reasons stated in the Brief and Reply Brief,
and those reasons set forth below.
OPINION
A. The Rejections under 35 U.S.C. § 112, ¶1 and ¶2
The examiner finds that claims 9 and 13 recite source and
drain contact structures extending through the shallow trench
isolation (STI)(Answer, sentence bridging pages 3-4). The examiner
states that it is “well known” in the art that STI is “defined” as
a shallow trench formed inside and below the substrate to isolate
Appeal No. 2002-2087
Application No. 09/733,836
2See Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1563, 19
USPQ2d 1111, 1117 (Fed. Cir. 1991); and In re Angstadt, 537 F.2d
498, 501, 190 USPQ 214, 217 (CCPA 1976).
4
active regions of the semiconductor device, and a trench “by
definition” can not be formed on the surface of the substrate
(Answer, page 4). Since the examiner finds that the source and
drain contact structures are not formed below the substrate
surface, the examiner determines that there is no support for
source and drain contact structures extending through the STI
(id.).
Accordingly, the examiner also finds that the claims are
indefinite under paragraph two of section 112 since it is “unclear
as to how a trench can be formed over the substrate” (Answer, page
4).
Although the examiner appears to confuse the requirements of
section 112 for written description, enablement, and definiteness,2
the initial burden of establishing unpatentability on any ground
rests with the examiner. See In re Oetiker, 977 F.2d 1443, 1445,
24 USPQ2d 1443, 1444 (Fed. Cir. 1992). Under the written
description requirement of the first paragraph of section 112, the
examiner must establish that the originally filed disclosure would
not have reasonably conveyed to one of ordinary skill in this art
Appeal No. 2002-2087
Application No. 09/733,836
5
that appellants had possession of the now claimed subject matter.
See In re Edwards, 568 F.2d 1349, 1351-52, 196 USPQ 465, 467 (CCPA
1978). “The legal standard for definiteness [under section 112,
¶2] is whether a claim reasonably apprises those of skill in the
art of its scope. [Citations omitted].” In re Warmerdam, 33 F.3d
1354, 1361, 31 USPQ2d 1754, 1759 (Fed. Cir. 1994).
We determine that the examiner has not met this initial burden
for either rejection under the first or second paragraphs of
section 112. Regarding the examiner’s rejection under the second
paragraph, the specification and drawing clearly shows how a trench
can be formed over and into a substrate (specification, page 5, ll.
29-30, and Figure 1). The examiner has failed to establish that a
trench cannot be “by definition” formed on the surface of the
substrate, with no evidence of any “definition” on this record. As
correctly argued by appellants (Reply Brief, pages 5-6), the
applied prior art in this appeal establishes that STIs can be
formed over the substrate. With regard to the rejection under the
first paragraph of section 112, the examiner’s statement that there
is no support for source and drain contact structures extending
through the STI “as recited in claims 9 and 13" is incorrect
(Answer, page 4). Claim 9 on appeal recites that the source and
drain contact structures are formed on the STI and extend through
Appeal No. 2002-2087
Application No. 09/733,836
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the STI to contact the source and drain diffusion regions (and thus
these contact structures do not extend through the entire STI).
Support for this recitation in claim 9 is clearly found in the
specification (page 6, ll. 1-3) and Figure 1.
For the foregoing reasons and those stated in the Brief and
Reply Brief, we determine that the examiner has failed to meet the
initial burden of establishing failure to meet the requirements of
35 U.S.C. § 112, first and second paragraphs. Accordingly, we
reverse the rejections of claims 9-16 under ¶1 and ¶2 of 35 U.S.C.
§ 112.
B. The Rejection under 35 U.S.C. § 103(a)
The examiner finds that Lin teaches, in Figure 6 and related
text, an ESD structure comprising a p type semiconductor substrate
20 [sic, 10; see Lin, col. 3, l. 30], n+ source and drain diffusion
regions 43, and respective source and drain n-wells 21, under each
diffusion region, and STI 30 formed over and into the substrate “to
separate the source and drain diffusion regions and a portion of
the source and drain wells” (Answer, page 5). The examiner admits
that Lin does not explicitly state that STI regions separate the
source and drain diffusion regions and a portion of the source and
drain wells, but the examiner states that “it is well known in the
art that STI regions separate active regions of one device from
Appeal No. 2002-2087
Application No. 09/733,836
7
active regions of adjacent devices on the substrate.” Id. The
examiner finds that Lin teaches that the STI regions separate each
active region (id., citing col. 3, ll. 32-33). Therefore the
examiner finds that the STI regions of Lin separate the source and
drain diffusion regions and a portion of the source and drain wells
of device 40 from other devices or from other active regions on the
substrate. (Answer, pages 5 and 10).
The examiner recognizes that Lin does not teach forming source
and drain contact structures on the isolation regions over the
source and drain diffusion regions and extending these contact
structures through the STI to contact the source and drain
diffusion regions (Answer, page 5). Accordingly, the examiner
applies Williams for the teaching of source and drain contact
structures formed on the isolation regions and extending through
these regions to contact the source and drain diffusion regions
(Answer, page 6, citing Figure 14). From these findings, the
examiner concludes that it would have been obvious, as taught by
Williams, to form source and drain contact structures on the
isolation regions to contact the source and drain diffusion regions
in the Lin device “in order to activate the device by providing
external connections to the source and drain regions.” Id. The
examiner notes that the Lin device as depicted in Figure 6 is not a
Appeal No. 2002-2087
Application No. 09/733,836
8
“final structure” and cannot operate without source and/or drain
contact structures over the active regions (id.).
We agree with the examiner’s claim construction, namely that
claim 9 on appeal does not require that the STI separates the
source and drain diffusion regions of the same device (Answer, page
10). The claimed language must be construed as broadly as
reasonably possible when read in light of the specification as it
would have been understood by one of ordinary skill in this art.
See In re Morris, 127 F.3d 1048, 1054, 44 USPQ2d 1023, 1027 (Fed.
Cir. 1997). However, even in light of this claim construction, the
examiner has not established, by convincing evidence or reasoning,
that Lin discloses, teaches or suggests a STI that separates “a
portion of the source and drain wells” (see claim 9). Therefore we
determine that the examiner’s finding is not supported by an
adequate factual basis.
When relying on numerous references or a modification of the
prior art to establish a prima facie case of obviousness, it is
incumbent on the examiner to identify some motivation, suggestion
or reason from the prior art or knowledge in the art that the
references would have been combined. See In re Mayne, 104 F.3d
1339, 1342, 41 USPQ2d 1451, 1454 (Fed. Cir. 1997). We determine
that the examiner has not established a convincing reason or
Appeal No. 2002-2087
Application No. 09/733,836
9
motivation to support the proposed combination of Lin and Williams
(see the Brief, pages 15-16; Reply Brief, pages 9-10). The
examiner states that the motivation or reason for combination is
“in order to activate the [Lin] device by providing external
connections to the source and drain regions.” Answer, page 6.
However, the examiner has not established that this motivation or
reason was disclosed or suggested by either Lin or Williams, known
to one of ordinary skill in this art, or would have been evident
from the nature of the problem to be solved. See Pro-Mold & Tool
Co. v. Great Lakes Plastics, Inc., 75 F.3d 1568, 1573, 37 USPQ2d
1626, 1629 (Fed. Cir. 1996). The examiner’s statement that the
device of Lin as shown in Figure 6 “is not a final structure” is
only a mere assertion that the examiner has not supported by any
evidence or convincing reasoning.
For the foregoing reasons and those stated in the Brief and
Reply Brief, we determine that the examiner has failed to establish
a prima facie case of obviousness in view of the reference
evidence. Accordingly, we cannot sustain the rejection of the
claims on appeal based on 35 U.S.C. § 103(a) over Lin in view of
Williams.
Appeal No. 2002-2087
Application No. 09/733,836
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C. Summary
The rejection of claims 9-16 under 35 U.S.C. § 112, first
paragraph, is reversed. The rejection of claims 9-16 under 35
U.S.C. § 112, second paragraph, is reversed.
The rejection of claims 9-16 under 35 U.S.C. § 103(a) over Lin
in view of Williams is reversed.
Appeal No. 2002-2087
Application No. 09/733,836
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The decision of the examiner is reversed.
REVERSED
TERRY J. OWENS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
THOMAS A. WALTZ ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
BEVERLY A. PAWLIKOWSKI )
Administrative Patent Judge )
TAW/jrg
Appeal No. 2002-2087
Application No. 09/733,836
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