Ex Parte Fujita

Board of Patent Appeals and Interferences

Dec 12, 2008

10390768 (B.P.A.I. Dec. 12, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte SHIGERU FUJITA
____________

Appeal 2008-3246
Application 10/390,768
Technology Center 2800
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Decided: December 12, 2008
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Before CHARLES F. WARREN, CATHERINE Q. TIMM, and
JEFFREY T. SMITH, Administrative Patent Judges.

SMITH, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal under 35 U.S.C. § 134 from the
Primary Examiner’s rejection of claims 6-9, 11, 12, 17-19, 21, and 22. We
have jurisdiction pursuant to 35 U.S.C. § 6. 1

1 In rendering this decision we have considered the Appellant’s arguments
presented in the Appeal Brief dated February 28, 2007 and the Reply Brief
dated September 26, 2007.

Appeal 2008-3246
Application 10/390,768

Appellant’s invention is directed to a method of manufacturing a
semiconductor device suitable for application to a semiconductor device that
includes a MIS (metal-insulator-semiconductor) transistor using a p-type
impurity-contained silicon layer as its gate electrode, for example. (Spec. 1).
Claim 6 is representative of the invention and is reproduced below:
6. A method of manufacturing a semiconductor device
comprising the steps of:

forming a high-dielectric-constant film on a semiconductor
substrate;

forming a nitride layer over the top surface of the high-
dielectric-constant film by introducing nitrogen into the top surface
portion of the high-dielectric-constant film by using radical nitrogen,

wherein the high-dielectric constant film is comprised of
enhanced dielectric materials including at least a Al2O3/HfO2/ Al2O3
multilayer structure,

wherein said nitride layer has a thickness less than 0.5 nm, and
wherein forming the nitride layer includes introducing the substrate
with the high-dielectric constant film into a nitriding apparatus,
evacuating a processing chamber of the nitriding apparatus,
introducing nitrogen gas into the processing chamber at approximately
300-400 sccm, and applying RF power to the processing chamber at a
rating of 200 to 1000 W.

ISSUES ON APPEAL
Claims 6-9, 11, 12, 17-19, 21, and 22 stand rejected under 35 U.S.C. §
103(a) as unpatentable over Callegari, U.S. Patent No. 6,664,186 B1, issued
December 16, 2003, in view of Pomarede, U.S. Patent No. 6,613,695 B2,
issued September 2, 2003, Hu, U.S. Patent Application Publication No.
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Appeal 2008-3246
Application 10/390,768

2003/0080389, dated May 1, 2003, and Bojarczuk U.S. Patent Application
Publication No. 2002/0190302 to dated December 19, 2002.
The Examiner contends that Callegari discloses a semiconductor
device that comprises the same structure as the device produced by
Appellant’s claimed method. However, the Examiner contends that
Callegari does not describe the claimed processing conditions. Specifically
the Examiner contends that Callegari does not disclose the manufacturing
method wherein nitride layer has a thickness about 0.2 nm -1.5nm, wherein
forming the nitride layer includes introducing the substrate with the high
dielectric constant film into the nitriding apparatus, evacuating a processing
chamber of the nitriding apparatus, introducing nitrogen gas into the
processing chamber at approximately 300-400 sccm, and applying RF power
to the processing chamber at a rating of 200 to 100 W. (Ans. 4). The
Examiner contends that Pomarede, Hu, and Bojarczuk are evidence that
these processing conditions are known to have been conventional. (Ans. 4-
8).
Appellant contends that the Examiner has failed to explain why it
would have been obvious to modify the structure of Callegari with the
structures described by Pomarede and Hu.2,3 (App. Br. 6-12; Reply Br. 2-9).

2 Appellant has grouped the arguments for claims 6-9, 11, 12, 17-19, 21, and
22 together. Consequently, the appealed claims stand or fall with
independent claim 6. Our analysis will be limited to claim 6.

3 The Examiner relied upon the Bojarczuk reference for elements that do not
appear in claim 6. Consequently, our discussion of the issues on appeal will
not include a discussion of the Bojarczuk reference.
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Appeal 2008-3246
Application 10/390,768

The issue presented is: did Appellant identify reversible error in the
Examiner’s rejection of claim 6 under § 103? We answer this question in
the negative. The issue turns on whether it would have been obvious to a
person of ordinary skill in the art to utilize conventional techniques for
forming a semiconductor substrate described in Callegari.
We have thoroughly reviewed each of Appellant’s arguments for
patentability. However, we are in complete agreement with the Examiner
that the claimed subject matter is not patentable within the meaning of § 103
in view of the applied prior art. Accordingly, we will sustain the Examiner’s
rejection.

OPINION
The Examiner found and Appellant does not dispute the following
facts (FF) in this appeal:
(1) Callegari describes a semiconductor device comprising a
nitride layer over the top surface of an
Al2O3/HfO2/Al2O3 high-dielectric-constant film on a
semiconductor substrate. (Ans. 3-4).
(2) Pomarede discloses process parameters, for
manufacturing a semiconductor, such as temperature,
pressure, plasma power, process duration and reaction in
concentrations can be adjusted dependent upon the
surface conditioning. (Ans. 5; Pomarede, col. 13, l. 59
to col. 14, l. 3).
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Application 10/390,768

(3) Pomarede describe a semiconductor manufacturing
method wherein the substrate with the high dielectric
constant film is introduced into the nitriding apparatus,
evacuating a processing chamber of the nitriding
apparatus, introducing nitrogen gas into the processing
chamber nitride layer has a thickness about 0.2 nm -
0.5nm. (Ans. 4-5; Pomarede col. 14, ll. 4-17).
(4) Hu describe a semiconductor manufacturing method
wherein the RF power lines in the processing chamber
had a rating of 200W to 2000W and a nitrogen radical
flow rate ranging from 1 to 100 sccm. (Ans. 5).
(5) The Examiner determined that a person of ordinary skill
in the art would have arrived at the claimed nitrogen gas
flow rate of approximately 300-400 sccm through
routine experimentation. (Ans. 6).
Under 35 U.S.C. § 103, the factual inquiry into obviousness requires a
determination of: (1) the scope and content of the prior art; (2) the
differences between the claimed subject matter and the prior art; (3) the level
of ordinary skill in the art; and (4) secondary considerations, if any. See
Graham v. John Deere Co., 383 U.S. 1, 17-18 (1966). “[A]nalysis [of
whether the subject matter of a claim is obvious] need not seek out precise
teachings directed to the specific subject matter of the challenged claim, for
a court can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ.” KSR Int’l Co. v. Teleflex Inc.,
127 S. Ct. 1727, 1740-41 (2007). “[I]f a technique has been used to improve
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Application 10/390,768

one device, and a person of ordinary skill in the art would recognize that it
would improve similar devices in the same way, using the technique is
obvious unless its actual application is beyond his or her skill.” Id.; see also
DyStar Textilfarben GmBH & Co. Deutschland KG v. C.H. Patrick Co.,
464 F.3d 1356, 1361 (Fed. Cir. 2006) (“The motivation need not be found in
the references sought to be combined, but may be found in any number of
sources, including common knowledge, the prior art as a whole, or the
nature of the problem itself.”).
It is an axiomatic that where patentability is predicated upon a change
in a condition of a prior art element, such as a change in size, configuration
or concentration, the burden is on the applicant to establish which objective
evidence that the change is critical, i.e., it leads to a new, unexpected result.
In re Woodruff, 919 F.2d 1575, 1578 (Fed. Cir. 1990); In re Aller, 220 F.2d
454, 456 (CCPA 1955). In the present case, Appellant has not established
on this record that inlet orifices within the scope of the appealed claims
achieve a new, unexpected result regarding uniformity of a layer deposited
on a wafer.
Applying the preceding legal principles to the Factual Findings (FF)
in the record of this appeal, we determine that the Examiner has established
a prima facie case of obviousness, which prima facie case has not been
adequately rebutted by Appellant’s arguments. As shown by FF (1) above,
Callegari describes a semiconductor device comprising a nitride layer over
the top surface of an Al2O3/HfO2/Al2O3 high-dielectric-constant film on a
semiconductor substrate. As shown by FF (2-5) the processing conditions of
the claimed invention are conventional. A person of ordinary skill in the art
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Application 10/390,768

would have recognized that process parameters such as temperature,
pressure, plasma power, process duration, and reaction in concentrations
could be adjusted dependent upon the surface conditioning. (FF (2)). The
Examiner properly concluded that it would have been obvious to a person of
ordinary skill in the art to utilize conventional techniques for forming a
semiconductor substrate described in Callegari. Appellant has not indicated
that the claimed process parameters when so combined produce unexpected
results or that these conditions were not known to have been conventional to
a person of ordinary skill in the art. (See Briefs generally).
Regarding the Hu reference Appellant argues the Examiner has failed
to explain why the method of Hu would have been suitable for the problem
identified in Callegari. (App. Br. 10). Appellant’s argument is not
persuasive. Hu, like Callegari, is directed to the manufacture of
semiconductor devices. Thus, a person of ordinary skill in the art would
have reasonably expected that known conventional techniques such as those
described in Hu would have been suitable for forming the semiconductor
device of Callegari.
The Examiner contended that based upon the teachings of Pomarede
and Hu (FF (2-5)) it would have been obvious to a person of ordinary skill in
the art, depended upon surfacing conditions, to optimize the RF power and
the flow rate of the nitrogen into the semiconductor apparatus to obtain the
values of the claimed invention. (Ans. 5-6). Appellant has not argued that
the RF power and the flow rate of the nitrogen are not result effective
variables that depend upon surfacing conditions. (See Briefs generally).
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Consequently, Appellant has not adequately rebutted the Examiner's prima
facie case of unpatentability.
Appellant’s arguments regarding replacing the structures of Callegari
with the structures described by Pomarede and Hu are not persuasive. The
claimed invention is directed to a method of manufacturing a semiconductor
device. Appellant has not asserted that a person of ordinary skill in the art
would not have recognized that the processing conditions described in
Pomarede and Hu would not have been suitable for forming the structures of
Callegari. Appellant also has not directed us to evidence of unexpected
results, that are achieved by utilizing the combination of processing
conditions, to rebut the Examiner’s prima facie case.
For the foregoing reasons and those stated in the Answer, we affirm
the rejection presented in this appeal.
ORDER
The rejection of claims 6-9, 11-12, 17-19, 21, and 22 under 35 U.S.C. §
103(a) 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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PL Initial:
sld

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