Ex parte Chen

Board of Patent Appeals and Interferences

Apr 25, 2001

08495960 (B.P.A.I. Apr. 25, 2001)

1
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publication and is not binding precedent of the Board.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. 20
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte IH-CHIN CHEN
_____________
Appeal No. 1998-2884
Application No. 08/495,960
______________
ON BRIEF
_______________
Before JERRY SMITH, RUGGIERO, LEVY, Administrative Patent
Judges
RUGGIERO, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on the appeal from the final rejection
of claims 13-19, 21-26, and 28, which are the only claims
remaining in the application.
The disclosed invention relates to semiconductor
fabrication processes and particularly to a method of forming
a trench isolation structure in a stack trench capacitor
Appeal No. 1998-2884
Application No. 08/495,960
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fabrication process.
Representative claim 22 is reproduced as follows:
22. A method of making a semiconductor device
having a trench isolation structure formed in a
stack trench capacitor fabrication process,
comprising the steps of:
forming an interface layer onto a semiconductor
substrate;
forming a buffer layer onto the interface layer;
forming a trench region through the interface
layer, the buffer layer, and into the semiconductor
substrate;
forming a trench wall layer on interior walls of
the trench region, the trench wall layer being in
contact with a remaining interface layer on the
semiconductor substrate;
forming a conductive trench filler layer onto
the trench wall layer within the trench region;
forming a dielectric layer onto the trench
filler layer within the trench region;
forming a conductive layer onto the dielectric
layer within the trench region;
forming a trench cap layer on the conductive
layer such that the trench filler layer, the
dielectric layer, and the conductive layer are
surrounded by the trench wall layer and the trench
cap layer; and
forming a well structure on either side of the
Appeal No. 1998-2884
Application No. 08/495,960
The Appeal Brief was filed May 12, 1997. In response to the1
Examiner’s Answer dated October 17, 1997, a Reply Brief was filed December 22,
1997, which was acknowledged and entered by the Examiner as indicated in the
communication dated March 2, 1998.
3
trench isolation structure such that said trench
isolation structure provides inter-well isolation.
The Examiner relies on the following prior art:
Iranmanesh 4,621,414 Nov. 11,
1986
Okada et al. (Okada) 4,700,464 Oct. 20,
1987
Claims 13-19 and 21 stand finally rejected as being based
on an inadequate disclosure under the first paragraph of 35
U.S.C.
§ 112. Claims 13-19 and 21 also stand finally rejected under
35 U.S.C. § 112, second paragraph, for failure to particularly
point out and distinctly claim the invention. Claims 22-26
and 28 stand finally rejected under 35 U.S.C. § 103(a) as
being unpatentable over Iranmanesh in view of Okada.
Rather than reiterate the arguments of Appellant and the
Examiner, reference is made to the Briefs and Answer for the1
Appeal No. 1998-2884
Application No. 08/495,960
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respective details thereof.
OPINION
We have carefully considered the subject matter on
appeal, the rejections advanced by the Examiner, the arguments
in support of the rejections and the evidence of obviousness
relied upon by the Examiner as support for the prior art
rejection. We have,
likewise, reviewed and taken into consideration, in reaching
our decision, Appellant’s arguments set forth in the Briefs
along with the Examiner’s rationale in support of the
rejections and arguments in rebuttal set forth in the
Examiner’s Answer. Although Appellant has
nominally asserted (Brief, page 4) the separate patentability
of each of the claims on appeal, separate arguments have been
provided only for independent claims 13, 15, and 22. We will
consider the appealed claims separately only to the extent
that separate arguments are of record in this appeal.
Dependent claims 14, 16-19, 21, 23-26, and 28 have not been
argued separately in the Briefs and, accordingly, will stand
Appeal No. 1998-2884
Application No. 08/495,960
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or fall with their base claim. Note In re King, 801 F.2d
1324, 1325, 231 USPQ 136, 137 (Fed. Cir. 1986); In re
Sernaker, 702 F.2d 989, 991, 217 USPQ 1, 3 (Fed. Cir. 1983).
It is our view, after consideration of the record before
us, that the disclosure in this application describes the
claimed invention in a manner which complies with the
requirements of the first paragraph of 35 U.S.C. § 112. We
are also of the view that the claims particularly point out
the invention in a manner which
complies with 35 U.S.C. § 112, second paragraph. We are of
the conclusion, however, that the evidence relied upon and the
level of skill in the particular art would have suggested to
one of ordinary skill in the art the obviousness of the
invention as set forth in claims 22-26 and 28. Accordingly,
we affirm-in-part.
With respect to the 35 U.S.C. § 112, first paragraph,
rejection, we note that the Examiner, instead of relying on
the “written description” or “enablement” language of the
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Application No. 08/495,960
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statute, has used the terminology “lack of support” in the
statement of the rejection. Our reviewing court has made it
clear that written description and enablement are separate
requirements under the first paragraph of 35 U.S.C. § 112.
Vas-Cath Inc. v. Mahurkar, 935 F.2d 1555, 1560, 19 USPQ2d
1111, 1114 (Fed. Cir. 1991). The terminology “lack of
support” has also been held to imply a reliance on the written
description requirement of the statute. In re Higbee and
Jasper, 527 F.2d 1405, 1406 188 USPQ 488, 489 (CCPA 1976).
In view of the factual situation presented to us in this
instance we will interpret the Examiner’s basis for the 35
U.S.C.
§ 112, first paragraph rejection as reliance on the “written
description” portion of the statute. “The function of the
description requirement [of the first paragraph of 35 U.S.C.
§ 112] is to ensure that the inventor has possession, as of
the filing date of the application relied on, of the specific
Appeal No. 1998-2884
Application No. 08/495,960
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subject matter later claimed by him.” In re Wertheim, 541
F.2d 257, 262, 191 USPQ 90, 96 (CCPA 1976).
In establishing a basis for a rejection under the written
description requirement of the statute, the Examiner has the
initial burden of presenting evidence or reasons why persons
skilled in the art would not recognize in an applicant’s
disclosure a description of the invention defined by the
claims. Wertheim, 541 F.2d at 265, 191 USPQ at 98. After
reviewing the arguments of record, however, it is our opinion
that the Examiner has not provided sufficient reasons or
evidence to satisfy such burden.
The Examiner asserts (Answer, pages 3 and 6-8) a lack of
description in Appellant’s specification of the formation of a
stack trench capacitor “concurrently and integratedly” with
the formation of a trench isolation structure in the same
fabrication
process as set forth in appealed independent claims 13 and 15.
We agree with Appellant however that, in integrated circuit
manufacturing, different structures are routinely formed
Appeal No. 1998-2884
Application No. 08/495,960
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concurrently on a substrate with fabrication steps added or
eliminated as needed. We further find to be persuasive
Appellants’ contention (Reply Brief, page 2) that the skilled
artisan would find it illogical to include unneeded and
possibly undesirable conductive layers in a trench isolation
structure as presently claimed unless these layers are formed
concurrently during formation of the stack trench capacitor
where such conductive layers are necessary.
Further, while we agree with the Examiner (Answer, page
8) that a drawing illustration of the formation of the stack
trench capacitor and isolation structure on the same substrate
would be beneficial for a complete description of Appellant’s
invention, we do not find the absence of same to be fatal with
regard to a determination of compliance with the written
description portion of the statute. "It is not necessary that
the application describe the claim limitations exactly, . . .
but only so clearly that persons of ordinary skill in the art
will recognize from the
disclosure that appellants invented processes including those
Appeal No. 1998-2884
Application No. 08/495,960
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limitations." Wertheim, 541 F.2d at 262, 191 USPQ at 96
citing In re Smythe, 480 F.2d 1376, 1382, 178 USPQ 279, 284
(CCPA 1973).
In view of the above discussion, it is our conclusion
that, under the factual situation presented in the present
case, the statutory written description requirement has been
satisfied because Appellant was clearly in possession of the
invention at the time of filing of the application.
Therefore, we do not sustain the rejection of claims 13-19 and
21 under the first paragraph of 35 U.S.C. § 112.
Turning to a consideration of the 35 U.S.C. § 112, second
paragraph, rejection of claims 13-19 and 21, we note that the
general rule is that a claim must set out and circumscribe a
particular area with a reasonable degree of precision and
particularity when read in light of the disclosure as it would
be by the artisan. In re Moore, 439 F.2d 1232, 1235, 169 USPQ
236, 238 (CCPA 1971). Acceptability of the claim language
depends on whether one of ordinary skill in the art would
understand what is claimed in light of the specification.
Seattle Box Co. v. Industrial Crating & Packing, Inc., 731
F.2d 818, 826, 221 USPQ 568, 574 (Fed. Cir. 1984).
Appeal No. 1998-2884
Application No. 08/495,960
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After reviewing the arguments of record, we are in
agreement with Appellant (Brief, page 8) that, contrary to the
Examiner’s contention, two independent processes are not being
recited in independent claims 13 and 15. Rather, it is our
view that the skilled artisan reading claims 13 and 15 in
light of Appellant’s specification would recognize that, as
asserted by Appellant, the trench isolation structure is
formed within the process flow for forming the stack trench
capacitor. Similarly, we find the Examiner’s assertion that
claim 15 is incomplete to be unfounded.
Claim 15 is directed to the formation of a trench isolation
structure, albeit within a DRAM forming process according to
the claim preamble; however, all steps required for forming
such isolation structure are in fact recited.
It is our view that the skilled artisan, having
considered the specification in its entirety, would have no
difficulty ascertaining the scope of the invention recited in
claims 13-19 and 21. Therefore, the rejection of claims 13-19
and 21 under the second paragraph of 35 U.S.C. § 112 is not
sustained.
Appeal No. 1998-2884
Application No. 08/495,960
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We next consider the Examiner’s rejection of claims 22-26
and 28 under 35 U.S.C. § 103 as being unpatentable over
Iranmanesh in view of Okada. As a general proposition in an
appeal involving a rejection under 35 U.S.C. § 103, an
Examiner is under a burden to make out a prima facie case of
obviousness. If that burden is met, the burden of going
forward then shifts to Appellant to overcome the prima facie
case with argument and/or evidence. Obviousness is then
determined on the basis of the evidence as a whole and the
relative persuasiveness of the arguments. See In re Oetiker,
977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir. 1992); In
re Hedges, 783 F.2d 1038, 1039, 228 USPQ 685, 686 (Fed. Cir.
1986); In re Piasecki, 745 F.2d 1468, 1472, 223 USPQ 785, 788
(Fed. Cir. 1984); and In re Rinehart, 531 F.2d 1048, 1052, 189
USPQ 143, 147 (CCPA 1976). With respect to
representative independent claim 22, after reviewing the
Examiner’s analysis (Answer, pages 4 and 5), it is our view
that the Examiner has pointed out the teachings of the applied
Iranmanesh and Okada references, has reasonably indicated the
Appeal No. 1998-2884
Application No. 08/495,960
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perceived differences between this applied prior art and the
claimed invention, and has provided reasons as to how and why
this prior art would have been modified to arrive at the
claimed invention. In our view, the Examiner's analysis is
sufficiently
reasonable that we find that the Examiner has at least
satisfied the burden of presenting a prima facie case of
obviousness. The burden is, therefore, upon Appellant to come
forward with evidence or arguments which persuasively rebut
the Examiner’s prima facie case of obviousness. Arguments
which Appellant could have made but elected not to make in the
Briefs have not been considered in this decision (note 37 CFR
§ 1.192).
Appellant’s arguments in response (Brief, page 7)
initially attack the Examiner’s establishment of a prima facie
case of obviousness since neither Iranmanesh or Okada teaches
the concurrent fabrication of a trench stack capacitor and a
trench isolation structure. We find such arguments to be
Appeal No. 1998-2884
Application No. 08/495,960
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unpersuasive since they are not commensurate with the scope of
representative claim 22. It is axiomatic that, in proceedings
before the PTO, claims in an application are to be given their
broadest reasonable interpretation consistent with the
specification, and
that claim language should be read in light of the
specification as it would be interpreted by one of ordinary
skill in the art. In re Sneed, 710 F.2d 1544, 1548, 218 USPQ
385, 388 (Fed. Cir. 1983). Moreover, limitations are not to
be read into the claims
from the specification. In re Van Geuns, 988 F.2d 1181, 1184,
26 USPQ2d 1057, 1059 (Fed. Cir. 1993) citing In re Zletz, 893
F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir. 1989). As
pointed out by the Examiner (Answer, page 8), the process
steps set forth in claim 22, contrary to Appellant’s
assertions, recite only the steps for making a trench
isolation structure, a process to which the disclosures of
both Iranmanesh and Okada are directed.
Appeal No. 1998-2884
Application No. 08/495,960
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We further find unpersuasive Appellant’s argument that it
would not be obvious to modify the applied prior art to add
conductive layers since such are undesirable in a trench
isolation structure. In our view, there is no need to modify
the trench isolation structure of Iranmanesh to add upper and
lower conductive layers since the conductive polysilicon
layers 50 and 70 are already in place. The Examiner’s
modification of Iranmanesh extends only to the addition of
Okada’s teachings related to the use of the dual mask layers,
trench cap, and well
structure features. Appellant has not argued the obviousness
of adding the dual mask layers of Okada to Iranmanesh.
Further, in our view, Appellant’s arguments related to the
trench cap and well structure are unconvincing since a clear
teaching exists in Okada for employing such features in an
isolation structure.
For the above reasons, it is our opinion that, since the
Examiner’s prima facie case of obviousness has not been
rebutted by any convincing arguments from Appellant, the
Appeal No. 1998-2884
Application No. 08/495,960
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Examiner’s obviousness rejection of independent claim 22, as
well as dependent claims 23-26 and 28 which fall with claim
22, is sustained.
In summary, we have not sustained the Examiner’s 35
U.S.C.
§ 112, first and second paragraph, rejections of claims 13-19
and 21. We have, however, sustained the Examiner’s 35 U.S.C.
§ 103 rejection of claims 22-26 and 28. Therefore, the
Examiner’s decision rejecting claims 13-19, 21-26, and 28 is
affirmed-in-part.
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a).
AFFIRMED-IN-PART

Appeal No. 1998-2884
Application No. 08/495,960
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JERRY SMITH )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
JOSEPH F. RUGGIERO ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
STUART S. LEVY )
Administrative Patent Judge )
jfr/vsh
Appeal No. 1998-2884
Application No. 08/495,960
17
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