Ex Parte Rajagopalan et al

Patent Trial and Appeal Board

Oct 23, 2012

10828023 (P.T.A.B. Oct. 23, 2012)

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.
10/828,023 04/19/2004 Nagarajan Rajagopalan AMAT/8583/DSM/LOW
K/JW
4576
7590 10/24/2012
Applied Materials
Patent Counsel - Legal Affairs Department
P.O. Box 450A
Santa Clara, CA 95052
EXAMINER
BURKHART, ELIZABETH A
ART UNIT PAPER NUMBER
1715
MAIL DATE DELIVERY MODE
10/24/2012 PAPER
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.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte NAGARAJAN RAJAGOPALAN, MEIYEE SHEK,
ALBERT LEE, ANNAMALAI LAKSHMANAN, LI-QUN XIA, and
ZHENJIANG CUI
____________

Appeal 2012-012091
Application 10/828,023
Technology Center 1700
____________

Before BRADLEY R. GARRIS, CHUNG K. PAK, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

GARRIS, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134 from the Examiner's
rejections under 35 U.S.C. § 103(a) of claims 17, 19-26, 28, 29, 48, and 49
as unpatentable over Bradshaw (US 6,869,873 B2 issued March 22, 2005) in
Appeal 2012-012091
Application 10/828,023

2
view of Ngo 634 (US 6,660,634 B1issued December 9, 2003), Filipiak (US
5,447,887 issued September 5, 1995), Yu (US 6,764,952 B1issued July 20,
2004), and Campana (US 2002/0119250 A1published August 29,2002) and
of claims 27 and 30 as unpatentable over these references and further in
view of Ngo 822 (US 6,432,822 B1issued August 13, 2002). We have
jurisdiction under 35 U.S.C. § 6.

We AFFIRM.

Appellants claim a method of processing a substrate which comprises:
positioning a substrate having a conductive material formed therein in a
processing chamber; introducing a silicon-based compound and a nitrogen-
containing reducing compound into the processing chamber at the same time
to form a nitrosilicide layer of the conductive material via a plasma-free,
thermally enhanced process; initiating a plasma of the silicon-based
compound and the nitrogen containing reducing compound to deposit a
silicon nitride layer on the nitrosilicide layer; and depositing a silicon
carbide layer on the silicon nitride layer (independent claim 17; see also
independent claim 28).

Representative claim 17 reads as follows:
17. A method for processing a substrate, sequentially
comprising:

Appeal 2012-012091
Application 10/828,023

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positioning the substrate in a processing chamber, wherein the
substrate comprises one or more patterned low k dielectric layers and a
conductive material formed therein;

introducing a silicon based compound and a nitrogen-containing
reducing compound into the processing chamber at the same time to form a
nitrosilicide layer of the conductive material, wherein the nitrosilicide layer
is formed by reacting the silicon based compound and the nitrogen-
containing reducing compound with the conductive material by a plasma-
free, thermally enhanced process;

initiating a plasma of the silicon based compound and the nitrogen-
containing reducing compound to deposit a silicon nitride layer on the
nitrosilicide layer; and

depositing a silicon carbide layer on the silicon nitride layer without
breaking vacuum.

As an initial matter, we observe that Appellants do not present
separate arguments directed to the dependent claims including separately
rejected dependent claims 27 and 30 (App. Br. 7-12). Accordingly, the
dependent claims will stand or fall with their parent independent claims 17
and 28 of which claim 17 is representative.

For the reasons well stated in the Answer, the Examiner has
established a prima facie case of obviousness for the subject matter defined
by representative claim 17. We sustain, therefore, the § 103 rejections
before us. The following comments are added for emphasis.

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Application 10/828,023

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As more fully detailed by the Examiner in the Answer, it would have
been prima facie obvious to introduce a nitrogen-containing reducing
compound along with the silicon-based compound of Bradshaw’s
silicidation process (i.e., to form copper silicide) in order to improve
adhesion as taught by Ngo 634 and Campana and to perform this silicidation
process in the absence of a plasma followed by a plasma deposition of
silicon nitride as taught by Filipiak in order to improve adhesion of
Bradshaw’s SiC capping layer as taught by Yu (Ans. 3-5, 8-9). Further, the
Examiner has established a reasonable basis for believing that the nitrogen-
containing reducing compound would inherently form a nitrosilicide layer
during the silicidation process in view of the substantially overlapping
process conditions disclosed in the prior art and in Appellants’ Specification
(id. at para. bridging 9-10).

Appellants argue that the Examiner’s inherency position is
undermined by Ngo 634 and Filipiak because Ngo teaches forming copper
silicide using plasma and Filipiak teaches forming silicon nitride using
plasma whereas the claimed invention forms a nitrosilicide layer by a
plasma-free process (App. Br. 9-10).

Appellants’ argument is unpersuasive because it is based on a
misunderstanding of the Examiner’s rejection. As indicated above, the
Examiner relies on Filipiak’s teachings of performing a silicidation process
in the absence of a plasma in order to form copper silicide followed by a
plasma deposition of silicon nitride (see, e.g., Filipiak Abst., Ans. 8-9).
Appeal 2012-012091
Application 10/828,023

5
When modified as proposed by the Examiner, Bradshaw’s silicidation
process would form the desired copper silicide in the presence of a nitrogen-
containing reducing compound as taught by Ngo 634 via a plasma-free
process as taught by Filipiak. Based on the record before us, the resulting
plasma-free silicidation process is indistinguishable from the plasma-free
process by which is formed the nitrosilicide layer of claim 17. We fully
share, therefore, the Examiner’s determination that the claimed nitrosilicide
layer would inherently form during the modified silicidation process of
Bradshaw.

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).
AFFIRMED

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