Ex Parte Wieczorek et al

Board of Patent Appeals and Interferences

Jun 24, 2009

10282665 (B.P.A.I. Jun. 24, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte KARSTEN WIECZOREK, VOLKER KAHLERT,
and MANFRED HORSTMANN
____________

Appeal 2009-002804
Application 10/282,665
Technology Center 2800
____________

Decided:1 June 25, 2009
____________

Before KENNETH W. HAIRSTON, MAHSHID D. SAADAT, and
KARL D. EASTHOM, Administrative Patent Judges.

SAADAT, Administrative Patent Judge.

DECISION ON APPEAL

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the decided date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).
Appeal 2009-002804
Application 10/282,665

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Appellants appeal under 35 U.S.C. § 134(a) from a Final Rejection of
claims 1, 2, 4-6, 8-15, and 17-28. Claims 3, 7, and 16 have been canceled.
We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.

STATEMENT OF THE CASE
Appellants’ invention relates to a method for forming a silicided
portion in a silicon region using a stack of layers, wherein a metal layer is
provided for forming the silicide layer while other layers are provided for
protecting the underlying metal layer (Spec. 7:20-24). Claim 1, which is
illustrative of the subject matter on appeal, reads as follows:
1. A method of forming a region of reduced
resistance in a silicon-containing conductive region, the method
comprising:
providing a substrate having formed thereon said silicon-
containing conductive region;
depositing a layer stack on the silicon-containing
conductive region, the layer stack comprising a first metal
layer, a second metal layer and a metal nitrogen compound
layer positioned between said first and second metal layers,
wherein depositing all layers of said layer stack is carried out in
situ in a single chamber; and
heat treating the substrate to form a metal silicide portion
in said silicon-containing conductive region, wherein heat
treating the substrate comprises a first annealing process at a
first average temperature and a second annealing process at a
second average temperature that is higher than the first average
temperature.
The Examiner relies on the following prior art references in rejecting
the claims:
Besser US 5,738,917 Apr. 14, 1998
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Takeuchi US 5,766,997 Jun. 16, 1998
Appellants’ Admitted Prior Art (AAPA), Spec. 2-7; Figures 1a-1c.
Claims 1, 2, 4-6, 8-15, and 17-28 stand rejected as being unpatentable
under 35 U.S.C. § 103(a) over Takeuchi, Besser, and AAPA.2
Rather than repeat the arguments here, we make reference to the
Appeal Brief (filed May 29, 2008), the Reply Brief (filed Oct. 10, 2008), and
the Answer (mailed Aug. 13, 2008) for the respective positions of
Appellants and the Examiner. Since no claims are argued separately from
the others, we decide this Appeal on the basis of representative independent
claim 1. See 37 C.F.R. § 41.37(c)(1)(vii) (“When multiple claims subject to
the same ground of rejection are argued as a group by appellant, the Board
may select a single claim from the group of claims that are argued together
to decide the appeal with respect to the group of claims as to the ground of
rejection on the basis of the selected claim alone.”). Further, only those
arguments actually made by Appellants have been considered in this
decision. Arguments which Appellants did not make in the Briefs have not
been considered and are deemed waived. See id.

ISSUE
Appellants’ contentions and the Examiner’s arguments present the
following issue:
Have Appellants shown that the Examiner erred in combining the
teachings of Takeuchi, Besser, and AAPA to arrive at the claimed invention?

2 Claim 8 appears to have inadvertently remained dependent upon canceled
claim 7.
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FINDINGS OF FACT
The following findings of fact (FF) are relevant to the issue involved
in the appeal.
1. The Examiner found (Ans. 3-4) that Takeuchi discloses forming
a region of reduced resistivity in a silicon region using a stack layer
136/137/138 of Ti/Ti-N/Ti (Takeuchi, col. 17, l. 3 – col. 18, l. 57; Fig. 13A-
14B).
2. The Examiner further relied on Besser for disclosing in situ
deposition of the Ti/Ti-N/Ti stack layer (Ans. 4) and on AAPA for teaching
a two-step anneal process for forming the metal silicide (Ans. 5).
3. Takeuchi teaches a heat treatment step, such as Rapid Thermal
Nitrization (RTN), for silicidation between the first titanium layer 136 and
the adjacent silicon region (col. 17, ll. 24-30).
4. Takeuchi, however, discloses that the silicidation stops at the
titanium nitride layer 137, while the thickness of the silicide layer depends
on the thickness of the titanium layer 136, not the temperature and time of
the heat treatment (col. 18, ll. 5-12).
5. Besser teaches a method for forming three layers of Ti, TiN,
and Ti using a single chamber of a vapor deposition system (col. 2, ll. 9-12).

PRINCIPLES OF LAW
Section 103 forbids issuance of a patent when “the differences
between the subject matter sought to be patented and the prior
art are such that the subject matter as a whole would have been
obvious at the time the invention was made to a person having
ordinary skill in the art to which said subject matter pertains.”
KSR Int'l Co. v. Teleflex Inc., 550 U.S. 398, 406 (2007).
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“‘The combination of familiar elements according to known methods
is likely to be obvious when it does no more than yield predictable results.’”
Leapfrog Enters., Inc. v. Fisher-Price, Inc., 485 F.3d 1157, 1161 (Fed. Cir.
2007) (quoting KSR, 550 U.S. at 416). “One of the ways in which a patent’s
subject matter can be proved obvious is by noting that there existed at the
time of invention a known problem for which there was an obvious solution
encompassed by the patent’s claims.” KSR, 550 U.S. at 419-20. The KSR
Court further recognized that “[w]hen there is a design need or market
pressure to solve a problem and there are a finite number of identified,
predictable solutions, a person of ordinary skill has good reason to pursue
the known options within his or her technical grasp.” Id. at 421.

ANALYSIS
Appellants’ arguments challenge combinability of the references and
whether one of ordinary skill in the art would have combined the two-step
heat treatment taught in AAPA and the in situ deposition of Ti/Ti-N/Ti stack
layers of Besser with the silicidation process of Takeuchi (App. Br. 5-15).
The Examiner has properly presented a prima facie case stating the relevant
teachings of each reference (FF 1-2) and arguing the reasons as to why one
of ordinary skill in the art would have combined the references to arrive at
the claimed invention (Ans. 18-22). The Examiner also relied on the
principles outlined in KSR to combine well-known processes available to the
skilled artisan in order to improve similar processes and to yield predictable
results (Ans. 22-24).
We disagree with Appellants (App. Br. 8-9; Reply Br. 2-3) that
Takeuchi teaches away from using the two-step heat treatment disclosed in
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AAPA. The Examiner made a finding (Ans. 21), based on the disclosure of
Takeuchi (FF 1), that Takeuchi is not limited to a single anneal process. The
Examiner properly concluded (id.) that Takeuchi, while providing an
example such as RTN (FF 3), specifies neither a preference for the heat
treatment conditions as long as the entire Ti layer goes through a silicidation
process (FF 4), nor a limitation on how the stack layer should be formed.
Similarly, we agree with the Examiner’s conclusion (Ans. 21-22) that using
the specific in situ process of Besser for deposition of the Ti/Ti-N/Ti stack
layer (FF 5) and the two-step heat treatment of AAPA provide additional
improvements to the process of Takeuchi.

CONCLUSION
For the reasons discussed above and provided by the Examiner, we
conclude that Appellants have not shown error in the Examiner’s
combination of the references and sustain the 35 U.S.C. § 103(a) rejection of
claims 1, 2, 4-6, 8-15, and 17-28 over Takeuchi, Besser, and AAPA.

ORDER
The decision of the Examiner rejecting claims 1, 2, 4-6, 8-15, and 17-
28 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)(1)(iv).

AFFIRMED

Appeal 2009-002804
Application 10/282,665

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