Ex Parte Slater et al

Board of Patent Appeals and Interferences

Jan 11, 2012

10916113 (B.P.A.I. Jan. 11, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
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.
10/916,113 08/11/2004 David B. Slater JR. 5308-315 9174
20792 7590 01/12/2012
MYERS BIGEL SIBLEY & SAJOVEC
PO BOX 37428
RALEIGH, NC 27627
EXAMINER
QUACH, TUAN N
ART UNIT PAPER NUMBER
2893
MAIL DATE DELIVERY MODE
01/12/2012 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 BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte DAVID B. SLATER, JR., JOHN EDMOND,
and MATTHEW DONOFRIO
____________

Appeal 2009-011624
Application 10/916,113
Technology Center 2800
____________

Before MAHSHID D. SAADAT, ALLEN R. MacDONALD,
and ERIC B. CHEN, Administrative Patent Judges.

SAADAT, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from the rejection of
claims 1-4, 14-16, 18-21, 23, and 64-69. Claims 13, 22, and 54-63 have
been canceled and claims 5-12, 17, and 24-53 have been withdrawn from
consideration. We have jurisdiction under 35 U.S.C. § 6(b).
We affirm.
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STATEMENT OF THE CASE
Appellants’ invention relates to a method for forming ohmic contacts
on silicon-carbide (SiC) substrates by localized annealing of the metal and
SiC interface (see Spec. 3:23-29).
Exemplary independent claim 1 reads as follows:
1. A method of forming an ohmic contact for a
semiconductor device, comprising:
forming a metal on a Silicon Carbide (SiC) layer; and
annealing an interface location of the metal and the SiC
layer at an energy level above a bandgap of the SiC layer to
form a metal-SiC material to provide the ohmic contact thereat
and avoiding annealing at a location on the SiC layer to avoid
forming the metal-SiC material thereat.

The Examiner relies on the following prior art in rejecting the claims:
Shirai US 4,672,740 Jun. 16, 1987
Ota US 6,110,813 Aug. 29, 2000
Tomoda US 6,878,574 B2 Apr. 12, 2005

Eryu, O., et al. (Eryu), “Formation of an ohmic electrode in SiC using
a pulsed laser irradiation method,” Nuclear Instruments and Methods in
Physics Research, B, Vol. 121, 1997, pp.419-421.

IBM Technical Disclosure Bulletin (IBM TDB), “Selective Metal
Deposition by a Resistless Liftoff Process,” Vol. 29, No. 10, March 1987, p.
4250.
Claims 1-4 stand rejected under 35 U.S.C. § 112, first paragraph, as
being based on an inadequate disclosure.
Claims 1-4, 14-16, 18, 19, 64, and 65 stand rejected under 35 U.S.C.
§ 102(b) as being anticipated by Eryu.
Claims 66 and 67 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Eryu.
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Claims 1-4, 14-16, 18-21, 23, and 64-67 stand rejected under
35 U.S.C. § 103(a) as being unpatentable over Ota, Eryu, and Tomoda.
Claim 68 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Eryu or Ota, in view of IBM TDB.
Claim 69 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Eryu or Ota as applied to claim 68, and further in view of
Shirai.

PRINCIPLES OF LAW
Written Description
The function of the written 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 subject matter
later claimed by him. In re Wertheim, 541 F.2d 257, 262 (CCPA 1976);
Vas-Cath, Inc. v. Mahurkar, 935 F.2d 1555, 1563 (Fed. Cir. 1991). 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.
Enablement
To be enabling, the specification must teach those of skill in the art
“how to make and how to use the invention as broadly as it is claimed.” In
re Vaeck, 947 F.2d 488, 496 (Fed. Cir. 1991). Furthermore, the
specification, when filed, must enable one skilled in the particular art to use
the invention without undue experimentation. In re Wands, 858 F.2d 731,
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737 (Fed. Cir. 1988). See also Spectra Physics v. Coherent, 827 F.2d 1524,
1533 (Fed. Cir. 1987).
Anticipation
In rejecting claims under 35 U.S.C. § 102, “[a] single prior art
reference that discloses, either expressly or inherently, each limitation of a
claim invalidates that claim by anticipation.” Perricone v. Medicis
Pharmaceutical Corp., 432 F.3d 1368, 1375-77 (Fed. Cir. 2005); see also In
re Paulsen, 30 F.3d 1475, 1478-79 (Fed. Cir. 1994). “Anticipation of a
patent claim requires a finding that the claim at issue ‘reads on’ a prior art
reference.” Atlas Powder Co. v. IRECO, Inc., 190 F.3d 1342, 1346 (Fed.
Cir. 1999) (quoting Titanium Metals Corp. of Am. v. Banner, 778 F.2d 775,
781 (Fed. Cir. 1985)).

ANALYSIS
Rejection under 35 U.S.C. § 112, first paragraph
The Examiner has taken the position (Ans. 3-4) that Appellants’
disclosure lacks a written description of “annealing an interface location of
the metal and the SiC layer at an energy level above a bandgap of the SiC
layer” recited in independent claim 1. The Examiner states that, while pages
5, 6, and 18 of Appellants’ Specification describe laser annealing, no support
exists for the laser light to include energies above a bandgap of the SiC
substrate (id.).1
Appellants respond by stating that the Examiner has not met the
burden of showing a lack of written description and enablement since no

1 The Examiner further refers to the deficiency of Appellants’ disclosure as
lack of enablement (Ans. 4).
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evidence or reason has been provided to show why a person having skill in
the art would not recognize the claims as supported by adequate written
description (Br. 7). Appellants further argue that the Examiner has not
shown that the operation of laser annealing to achieve the claimed energy
level requires undue experimentation, which indicates enabling disclosure
and possession by Appellants of the claimed invention when the application
was filed (Br. 7-8).
Based on a review of Appellants’ Specification, we agree that
Appellants’ description of the laser annealing would have been recognized
by one of ordinary skill in the art as providing sufficient support for the
claimed anneal energy. We specifically find that Appellants’ Specification
provides a general teaching for the claimed anneal process and the suggested
energy levels which are recognized by one of ordinary skill in the art to be
sufficient for performing, without undue experimentation, the anneal process
at different energy levels, such as above the bandgap of the SiC layer.
In view of the above discussion and considering the presented facts
and the arguments made by Appellants and the Examiner, we find that
Appellants’ disclosure is enabling and indicates that the Appellants were in
possession of the claimed subject matter at the time of filing of the
application. Therefore, the rejection of claims 1-4 under the first paragraph
of 35 U.S.C. § 112 cannot be sustained.
Rejection under 35 U.S.C. § 102
With respect to claim 1, the Examiner reads the claimed anneal
process on the process for forming ohmic contacts disclosed in Eryu wherein
annealing in the areas not desired is blocked (Ans. 5). Appellants contend
that, based on the contact resistance, the process disclosed in Eryu does not
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result in forming ohmic contacts (Br. 8). Appellants point out that
Appellants’ disclosed process as described in page 10 of the Specification
defines an ohmic contact having resistivity lower than what Eryu provides
(Br. 9). Appellants conclude that Eryu does not disclose a process for
forming an ohmic contact (id.).
Based on a review of how Eryu forms the metal contact to the SiC
layer, we agree with the Examiner (Ans. 13-16) and find that the process
discussed in Eryu results in forming ohmic contacts because the anneal
process is similar to the process discussed in Appellants’ Specification.
While Appellants have described the desired resistivity levels for an ohmic
contact (see Br. 9; Spec. 10:18-24), such values are not recited in the claims.
Nor have Appellants provided any specific processes, other than heating the
deposited metal layer, for forming an ohmic contact. Therefore, to the
extent disclosed in Appellants’ Specification, we find that the process for
annealing portions of the metal-Sic interface in Eryu results in forming
ohmic contacts and meets the claimed process.
In view of our analysis above, we find that the teachings of Eryu,
when considered as a whole, support the Examiner’s § 102 ground of
rejection. Therefore, we sustain the rejection of claims 1-4, 14-16, 18, 19,
64, and 65 under 35 U.S.C. § 102(b).
Rejections under 35 U.S.C. § 103
Claims 66 and 67
Appellants present no additional arguments for claims 66 and 67 and
merely assert (Br. 10) the patentability of these claims based on the same
reasons provided for claim 1, which were found to be unpersuasive.
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Therefore, for the same reasons set forth above, we sustain the rejection of
claims 66 and 67 under 35 U.S.C. § 103(a).
Claims 1-4, 14-16, 18-21, 23, and 64-67
With respect to the rejection of these claims over Ota, Eryu, and
Tomoda, Appellants rely on similar arguments presented against Eryu for
claim 1 above and add that Ota uses different laser energies which would not
work in the process of Eryu (Br. 10-11). The Examiner responds by
asserting that the claims are not limited to any particular resistivity or laser
energy (Ans. 17-18). We agree with and adopt the Examiner’s findings and
conclusions provided in response to Appellants’ contentions (see id.). For
emphasis, we must point out, however, that all of the features of the
secondary reference need not be bodily incorporated into the primary
reference (see In re Keller, 642 F.2d 413, 425 (CCPA 1981)) and the artisan
is not compelled to blindly follow the teaching of one prior art reference
over the other without the exercise of independent judgment (see Lear
Siegler, Inc. v. Aeroquip Corp., 733 F.2d 881, 889 (Fed. Cir. 1984)).
Therefore, the 35 U.S.C. § 103(a) rejection of claims 1-4, 14-16, 18-21, 23,
and 64-67 is also sustained.
Claims 68 and 69
Regarding the rejection of claim 68 over Eryu or Ota in view of IBM
TDB, Appellants repeat the argument against forming ohmic contacts in
Eryu and further contend that Ota anneals an already patterned metal layer
and cannot be combined with the blanket metal layer disclosed in IBM TDB
(Br. 11-12). We again agree with the Examiner’s findings and conclusions
(see Ans. 19-22) and note that Appellants’ challenge to the references
individually is not convincing of error in the Examiner’s position. See
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Keller, 642 F.2d at 425 (one cannot show nonobviousness by attacking
references individually where the rejections are based on combination of
references). Appellants rely on the same reasons argued for claim 68 in
support of the patentability of claim 69 (Br. 12). Therefore, we sustain the
35 U.S.C. § 103(a) rejection of claims 68 and 69.

DECISION
The Examiner’s decision rejecting claims 1-4, 14-16, 18-23, and 64-
69 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

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