Ex parte Paranjpe

Board of Patent Appeals and Interferences

Aug 30, 2001

08722904 (B.P.A.I. Aug. 30, 2001)

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publication and is not binding precedent of the Board.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 AJIT P. PARANJPE
____________
Appeal No. 1999-1655
Application No. 08/722,904
____________
ON BRIEF
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Before THOMAS, KRASS, and DIXON, Administrative Patent Judges.
DIXON, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner's final rejection of claims 1-4. Claim 5
is directed to a non-elected invention. Claims 1-5 are all of the claims pending in this
application.
We AFFIRM-IN-PART.
Appeal No. 1999-1655
Application No. 08/722,904
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BACKGROUND
The appellant's invention relates to an integrated circuit interconnect. The invention
uses ion implantation and annealing to encapsulate the vertical sidewalls of a clad metal
structure or trench in a dielectric material. An understanding of the invention can be
derived from a reading of exemplary claims 1 and 3, which are reproduced below.
1. A method of encapsulating clad metal structures in an integrated
circuit, comprising the steps of:
(a) providing a partially formed integrated circuit with a clad metal
structure including a first metal structure and a cladding metal on a top
horizontal surface of the first metal; and
(b) implanting dopants into exopsed [sic; exposed] first metal vertical
sidewalls of said clad metal structure to form vertical surface regions of first
metal-dopant mixtures.
3. A method of encapsulating metal structures in an integrated circuit,
comprising the steps of:
(a) providing a partially formed integrated circuit with a dielectric layer
including trenches;
(b) implanting dopants into surface regions of sidewalls of said
trenches;
(c) filling said trences [sic; trenches] with metal to form metal
structures with said dopants adjacent said metal structures; and
(d) after said filling with metal, annealing said metal structure and
dielectric with said implanted dopants to form metal surface regions of
metal-dopant compounds.
Appeal No. 1999-1655
Application No. 08/722,904
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The prior art references of record relied upon by the examiner in rejecting the appealed
claims are:
Gelatos et al. (Gelatos) 5,391,517 Feb. 21, 1995
Choi 5,670,420 Sep. 23, 1997
(Filed Nov. 8, 1995)
Claims 1-4 stand rejected under 35 U.S.C. § 112, second paragraph, as being
indefinite in that a word is clearly misspelled in each of the independent claims 1 and 3.
Claims 1-4 stand rejected under 35 U.S.C. § 103 as being unpatentable over Choi in view
of Gelatos.
Rather than reiterate the conflicting viewpoints advanced by the examiner and the
appellant regarding the above-noted rejections, we make reference to the examiner's
answer (Paper No. 11, mailed Dec. 22, 1998) for the examiner's reasoning in support of
the rejections, and to the appellant's brief (Paper No. 10, filed Oct. 8, 1998) and reply brief
(Paper No. 12, filed Jan. 8, 1999) for the appellant's arguments thereagainst.
OPINION
In reaching our decision in this appeal, we have given careful consideration to the
appellant's specification and claims, to the applied prior art references, and to the
respective positions articulated by the appellant and the examiner. As a consequence of
our review, we make the determinations which follow.
Appeal No. 1999-1655
Application No. 08/722,904
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35 U.S.C. § 112, SECOND PARAGRAPH
Here, the examiner maintains that the presence of a single misspelled word in each of
the independent claims that makes the claims indefinite under 35 U.S.C. § 112, second
paragraph, and therefore lacks particularity and distinctness with respect to the claimed
invention. We disagree with the examiner. Here, the scope and content of the claims are
clear, and the examiner even provided the correct spelling in the office action. Therefore
we find that these errors in the claims do not form an appropriate basis for a rejection
under the statute, but the examiner may consider an objection under 37 CFR 1.75(a) or
correct the obvious typographical errors by examiner’s amendment. Therefore, we will not
sustain the rejection of claims 1-4 under 35 U.S.C. § 112, second paragraph.
35 U.S.C. § 103
“To reject claims in an application under section 103, an examiner must show an
unrebutted prima facie case of obviousness. See In re Deuel, 51 F.3d 1552, 1557, 34
USPQ2d 1210, 1214 (Fed. Cir. 1995). In the absence of a proper prima facie case of
obviousness, an applicant who complies with the other statutory requirements is entitled to
a patent. See In re Oetiker, 977 F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir.
1992). On appeal to the Board, an applicant can overcome a rejection by showing
insufficient evidence of prima facie obviousness or by rebutting the prima facie case with
Appeal No. 1999-1655
Application No. 08/722,904
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evidence of secondary indicia of nonobviousness.” In re Rouffet, 149 F.3d 1350, 1355,
47 USPQ2d 1453, 1455 (CAFC 1998). Here, we agree with the examiner’s rejection of
independent claim 3, and we find that appellant has not overcome the prima facie case of
obviousness by showing insufficient evidence by the examiner nor has appellant provided
evidence of secondary indicia of nonobviousness. But, we agree with appellant that the
examiner’s rejection lacks support for the invention as recited in claim 1. Therefore, we
find that appellant has overcome the prima facie case of obviousness by showing
insufficient evidence by the examiner with respect to independent claim 1.
With respect to independent claim 1, the examiner maintains that “implanting dopants
into exposed first metal vertical sidewalls of said clad metal structure to form vertical
surface regions of first metal-dopant mixtures ‘6’ ([Choi at] col. 2, lines 24-30)” provide
support for step (b) of claim 1. (See answer at page 3.) We disagree with the examiner.
Appellant argues that Choi does not teach or suggest the concept of implanting dopants
into exposed sidewalls of the clad metal structure to form vertical surface regions of first
metal-doped mixtures. (See brief at page 4.) We agree with appellant. Appellant argues
that the combination of Gelatos with Choi does not teach or suggest the invention of claim
1. (See brief at page 4.) We agree with appellant.
From our understanding of Choi, the third tungsten film 6 is formed “by a selective
deposition method so as to prevent the metal interconnection oxidizing due to an exposure
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in an atmosphere.” (See Choi at col.2, lines 26-29.) From the specific teachings of Choi
with respect to the formation of the layers and the specific processes used for each layer, it
is unreasonable for the examiner to maintain that the third tungsten layer/film 6 is formed by
ion implantation. Here, Choi specifically teaches deposition for layer 6 as opposed to the
ion implantation which is specifically taught for layers 2 and 4. The examiner has not
maintained that these methodologies are equivalent or that one is obvious in light of the
other. The examiner merely maintains that Choi teaches ion implantation for the vertical
surface regions. We disagree with the examiner and will not sustain the rejection of claim
1. With respect to claim 2 appellant argues that the combination of Choi and Gelatos does
not anneal the dopants in the sidewalls. (See brief at page 4.) We agree with appellant
and will not sustain the rejection of dependent claim 2.
With respect to independent claim 3, the examiner relies on Fig. 2 of Choi for the
teachings of ion implantation to improve the adhesion to the trench. Here, we note that
the first layer of tungsten 2 is formed by ion implantation in the trench in an oxide layer 1.
The examiner maintains that layer 1 is a dielectric layer. We agree with the examiner that
the oxide layer may be a dielectric layer with trenches therein. (See answer at page 3.)
The trenches are then filled with copper.
The examiner maintains that Choi does not teach the annealing of tungsten and metal
after the trench is filled. (See answer at page 3.) We note that Choi teaches annealing
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Application No. 08/722,904
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after the ion implantation of the tungsten rather than after deposition of copper. (Choi at
col. 2.) The examiner relies upon the teachings of Gelatos with respect to annealing
multiple layers to form intermetallic layers to promote superior adhesion and this would
have been desirable in the formation of Choi. (See answer at page 3.) We agree with the
examiner.
At page 5 of the brief, Appellant recites the steps of claim 3 and argues neither Choi or
Gelatos nor any proper combination of these references teaches or suggests the claimed
limitations. We disagree with appellant. In the answer, the examiner has identified the
relevant teachings in the prior art references and provided a motivation for the combination
which appellant has not adequately rebutted. Therefore, we will sustain the examiner
rejection of independent claim 3, and since Choi also discloses the limitation recited in
dependent claim 4, we will sustain this rejection also.
CONCLUSION
To summarize, the decision of the examiner to reject claims 1-4 under 35 U.S.C.
§ 112, second paragraph is reversed; the decision of the examiner to reject claims 1
and 2 under 35 U.S.C. § 103 is reversed, and the decision of the examiner to reject claims
3 and 4 under 35 U.S.C. § 103 is affirmed.
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Application No. 08/722,904
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AFFIRMED-IN-PART
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
ERROL A. KRASS ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JOSEPH L. DIXON )
Administrative Patent Judge )
JD/RWK
Appeal No. 1999-1655
Application No. 08/722,904
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CARLTON H. HOEL
TEXAS INSTRUMENTS PATENT DEPARTMENT
MAIL STATION 219
P O BOX 655474
DALLAS, TX 75265