Ex parte Fujimori et al.

Board of Patent Appeals and Interferences

Mar 9, 2000

08115783 (B.P.A.I. Mar. 9, 2000)

THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written
for publication in a law journal and (2) is not binding precedent of the Board.
Paper No. 40
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________
Ex parte NAOMI FUJIMORI, AKIHIKO IKEGAYA, TAKAHIRO IMAI,
NOBUHIRO OTA and TAKAYUKI SHIBATA
____________
Appeal No. 1996-3121
Application No. 08/115,783
____________
HEARD: February 23, 2000
____________
Before KIMLIN, JOHN D. SMITH, and WARREN, Administrative
Patent Judges.
JOHN D. SMITH, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal pursuant to 35 U.S.C. § 134 from the
final rejection of claims 1, 3-9, and 13-15.
Appealed claims 1 and 13 are representative and are
reproduced below:
1. A method for producing diamond by a CVD method
comprising:
Appeal No. 1996-3121
Application No. 08/115,783
2
decomposing and reacting a reaction gas containing
carbon atoms, hydrogen atoms, oxygen atoms and nitrogen gas, a
concentration of carbon atoms in relation to hydrogen gas
being (A%), a concentration of nitrogen gas in relation to the
whole reaction gas being (B ppm), and a concentration of
oxygen atoms in relation to the hydrogen gas being (C%), the
amounts of A, B and C satisfy the equation:
" = (B) x (A - 1.2C)½
wherein " is not larger than 13 or B is not larger than 20,
and wherein said carbon atoms comprise 99.9% or more of C or12
C.13
13. A synthetic diamond which is formed by a CVD method
on a substrate made of a material selected from the group
consisting of copper-tungsten alloy, gold, silver, copper
aluminum, a ceramic and a synthetic Ib type diamond single
crystal, wherein at least 99.9% of carbon in the synthetic
diamond comprises at least one carbon isotope selected from
the group consisting of C and C, a nitrogen content in the12 13
synthetic diamond is less than 20 ppm, and a ratio of a peak
height of non-diamond carbon to that of diamond in the Raman
spectroscopic spectrum of the synthetic diamond is not larger
than 0.07.
As evidence of obviousness of the claimed invention, the
examiner relies on the following references:
Seitz 3,895,313 Jul. 15, 1975
Sakamoto et al. (Sakamoto) 4,725,345 Feb. 16, 1988
Yamazaki 5,015,494 May 14, 1991
A reference relied upon by appellants is:
Appeal No. 1996-3121
Application No. 08/115,783
The Seitz patent refers to the Strong publication with1
respect to its disclosure of the absorption spectrum of
synthetic diamond having dispersed nitrogen impurities. See
Seitz at column 3, lines 60-68.
Appellants exemplify and utilize various prior art CVD2
techniques including microwave plasma CVD and hot filament
CVD. See the specification at page 3, lines 1-4.
3
Strong et al. (Strong) , “Further Studies on Diamond Growth1
Rates and Physical Properties of Laboratory-Made Diamond”, The
Journal of Physical Chemistry, Vol. 75, No. 12, 1971, pps.
1841-43.
Appealed claims 14 and 15 stand rejected under 35 U.S.C.
§ 112, first paragraph, “enablement requirement”. Appealed
claims 1, 3-7, 9 and 13-15 stand rejected under 35 U.S.C. §
103 as unpatentable over Yamazaki combined with Seitz.
Appealed claims 1, 3-9 and 13-15 stand rejected under 35
U.S.C. § 103 as unpatentable over Yamazaki and Seitz further
in view of Sakamoto.
The subject matter on appeal is directed to a synthetic
diamond coated on a substrate (appealed claims 13 and 15) and
a method for producing diamond by a chemical vapor
deposition(CVD) technique (appealed claims 1, 3-9, and 14)2
which involves the decomposition and reaction of a reaction
Appeal No. 1996-3121
Application No. 08/115,783
Sources of carbon for appellants’ process include, inter3
alia, methane and ethanol. See example 3 in the specification
at page 13.
4
gas which includes, inter alia, essentially isotopically pure3
carbon atoms which comprise “99.9% or more of C or C”,12 13
hydrogen atoms, oxygen atoms, and nitrogen gas. Additionally,
the concentration of the carbon atoms, the oxygen atoms, and
the nitrogen gas must satisfy an equation set forth in the
appealed method claims (see appealed claim 1 above) wherein "
is not larger than 13. Alternatively, according to claim 1,
the nitrogen gas is not larger than 20 ppm based on the total
reaction gas present. Significantly, appellants disclose that
by increasing the purity of carbon isotope utilized in the
claimed method, diamond having an a higher coefficient of
thermal conductivity is produced. See the specification at
pages 16 and 17. This makes the diamond layer or film
produced by the claimed method more desirable, when, for
example, it is used as a heat sink for a high output
integrated circuit or a laser diode. See the specification at
page 2, lines 1-3.
Appeal No. 1996-3121
Application No. 08/115,783
5
THE 35 U.S.C. § 112, FIRST PARAGRAPH ENABLEMENT
ISSUE
Appealed claims 14 and 15 stand rejected under the first
paragraph of 35 U.S.C. § 112, for the stated reason that “the
disclosure is enabling only for claims limited to the
substrates disclosed in the specification.” The examiner
further asserts that the claim language “metals having a
thermal conductivity of at least the thermal conductivity of
copper-tungsten alloy” covers substrates “not contemplated,
given that high-W alloy has a very low conductivity.” See the
answer at page 3.
For a proper rejection under the enablement provision of
35 U.S.C. § 112, it is incumbent upon the examiner to provide,
in the first instance, factual evidence and/or scientific
reasoning that one of ordinary skill in the art would be
required to resort to undue experimentation to practice the
invention as defined by the scope of the claims. In re
Strahilevitz, 668 F.2d 1229, 1232, 212 USPQ 561, 563-564 (CCPA
1982). In the present case, the examiner has presented no
such persuasive evidence or reasoning which supports the
conclusion that a skilled artisan would be unable to practice
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Application No. 08/115,783
See column 3, lines 40-43.4
See column 2, lines 1 and 2 of Yamazaki.5
6
the claimed invention without undue experimentation when using
metallic substrates having thermal conductivities at least as
high as copper-tungsten alloy. Compare the specification at
page 6, lines 10-17. Moreover, the mere possibility that a
claim covers an inoperable species does not render it unduly
broad. In re Kamal, 398 F.2d 867, 872, 158 USPQ 320, 324
(CCPA 1968). The examiner’s rejection of claims 14 and 15 is
reversed.
THE REJECTIONS FOR OBVIOUSNESS
As evidence of obviousness of the claimed invention, the
examiner principally relies upon Yamazaki. In a similar
manner as described by appellants, Yamazaki discloses that
diamond coatings may be formed on substrates by a microwave
enhanced CVD process in which a carbon compound containing
reactant gas including, inter alia, methanol diluted with4
hydrogen gas is decomposed in a reaction chamber to produce a
diamond film on an underlying substrate such as the “super
hard metal”, tungsten carbide . In addition to the carbon5
Appeal No. 1996-3121
Application No. 08/115,783
Since methanol is the sole source of the carbon and6
oxygen atoms in the prior art CVD plasma, the factor (A -1.2C)
in the equation is a negative number and thus the " value is
also a negative number. Therefore, the calculated " value is
less than 13 as required by the appellants’ claims for this
prior art embodiment.
7
compound, nitrogen gas is also “inputted” to the Yamazaki
reaction chamber to prevent the growth of lattice defects in
the diamond film. See column 1, lines 60-64.
The equation set forth in appealed claim 1 (which defines
" in terms of the nitrogen gas concentration B, the carbon
atom concentration A, and the oxygen atom concentration C) is
not disclosed in the prior art references relied upon by the
examiner. The examiner contends, however, that Yamazaki’s
described use of reactant gas mixture of methanol , hydrogen6
and nitrogen would necessarily satisfy the requirements of
appellants’ " equation, and appellants have not specifically
challenged the examiner’s factual finding. See the answer at
page 3. Therefore, we accept this finding as correct.
Accordingly, Yamazaki identically describes a CVD process for
producing diamond as required by appealed claim 1 with the
exception of the requirement that the carbon atoms must
comprise “99.9% or more C or C”. The narrow question thus12 13
Appeal No. 1996-3121
Application No. 08/115,783
See footnote 1 of this decision.7
8
raised by the examiner’s obviousness rejection of appealed
claim 1 is whether or not a person of ordinary skill in this
art would have been led to utilize an isotopically pure source
of carbon as required by appellants’ claim in the prior art
microwave enhanced CVD process described by Yamazaki. For the
reasons below, we answer this question in the affirmative.
Seitz, the “secondary reference” relied upon by the
examiner, discloses that the thermal conductivity of synthetic
diamond can be enhanced by growing the diamond “from only one
or the other of the isotopes of carbon 12 and carbon 13". See
column 2, lines 19-24 of Seitz. Appellants point out that
Seitz relates to a super high pressure method for forming
synthetic diamond, because “[T]he diamond of Seitz seems to7
be produced by the method described in the Strong... article”.
See pages 2-4 of appellants’ reply brief filed on February 28,
1995. Accordingly, appellants argue that there is no
justifiable motivation “for combining a super high pressure
method with a low pressure CVD method”. See the brief at page
10. On the other hand, we note that although Yamazaki is
Appeal No. 1996-3121
Application No. 08/115,783
There is no objective evidence of record to show how or8
why low pressure as utilized in a CVD process would adversely
affect a carbon isotope in such a process.
9
principally concerned with the formation of diamond films
possessing “high hardness” as coatings for the super hard
metal substrates such as tungsten carbide, the thermal
conductivity of the CVD produced diamond is a property of
interest to Yamazaki. See column 5, lines 49-51 of Yamazaki.
As appellants acknowledge in their specification at page 1,
lines 15-18, and page 2, lines 1-3, because diamond has a
“very large coefficient of thermal conductivity”, it is
especially useful as a heat sink for integrated circuits and
laser diodes. Accordingly, in light of the relevant
disclosures in Seitz and motivated by the goal of enhancing
the thermal conductivity of Yamazaki’s CVD diamond films, one
of ordinary skill in this art would have been led to use an
isotopically pure source of carbon 12 or carbon 13 in
Yamazaki’s CVD process to achieve this goal. Notwithstanding
appellants’ arguments in this record relating to the different
methodology utilized by Seitz, we know of no technical reason8
why one of ordinary skill in this art would not have a
Appeal No. 1996-3121
Application No. 08/115,783
10
reasonable expectation of successfully producing an
isotopically pure diamond film having enhanced thermal
conductivity when using an isotopically pure carbon source gas
in the CVD process of Yamazaki. We, therefore, sustain the
examiner’s obviousness rejection of appealed claim 1.
We also agree with the examiner that the subject matter
defined by appealed claims 3, 6, 7, 9, and 14 would have been
obvious to a person of ordinary skill in this art based on the
disclosures in Yamazaki and Seitz. Appealed claim 3 further
specifies that the carbon atoms in the reaction gas comprise
99.9% or more C. However, as emphasized above Seitz clearly12
teaches that the use of an isotope of only carbon 12 enhances
the property of thermal conductivity. Further, based on this
prior art teaching, one of ordinary skill in this art would
have reasonably expected to obtain a coefficient of thermal
conductivity for CVD diamond at least as high as required by
appealed claim 6. In this regard , compare the disclosures of
Strong at page 1843 inclusive of Figure 9. The subject matter
of appealed claim 7 is suggested by the disclosure of the use
of methanol, i.e., an alcohol, as a carbon source in
Yamazaki’s CVD process. Appealed claims 9 and 14 specify
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various substrates which, we observe, may be used, inter alia,
in “heat sink” applications. As observed above, it is known
in the art to make use of a diamond layer in such
applications. Accordingly, we agree with the examiner’s
conclusion that the subject matter defined by these claims
would have been obvious within the meaning of 35 U.S.C. § 103.
We cannot sustain the obviousness rejections of appealed
claims 4, 5, 8, 13 and 15. Claims 4, 5, 13, and 15 all
specify that the nitrogen content in the produced diamond is
20 ppm or less. As appellants persuasively argue, the
nitrogen content in Yamazaki’s diamond ranges from 100 to
10,000 ppm which is much greater than the nitrogen content
required by these claims. Moreover, Yamazaki provides
nitrogen for the purposeful function of preventing lattice
defects in the diamond, while it is appellants’ purpose to
avoid nitrogen contamination. See the specification at page
3, last paragraph. Under these circumstances, one of ordinary
skill in the art would not have been led to reduce the
required nitrogen content in Yamazaki’s process. Accordingly,
we cannot sustain the examiner’s rejection of claims 4, 5, 13
and 15.
Appeal No. 1996-3121
Application No. 08/115,783
12
Appealed claim 8 stands rejected under 35 U.S.C. § 103 as
unpatentable over the combined teachings of Yamazaki, Seitz,
and Sakamoto. This claim requires that the CVD method is
effected using a carbon filament containing at least 99.9% of
C or C. Thus, this claim implicitedly is limited to a hot12 13
filament CVD technique (specification, page 3, line 1 and
examples 13 and 14 at pages 22-24 of the specification) as
contrasted to a microwave enhanced CVD technique as disclosed
in Yamazaki. Since the microwave enhanced CVD technique
utilizes an IR heater, not a carbon filament, there is no
logical basis to support the argument that it would have been
obvious to modify the Yamazaki CVD apparatus in the manner
proposed by the examiner. Moreover, we find no disclosure in
Sakamoto that the graphite utilized in this prior art
vaporization process is either in the form of a filament or is
as isotopically pure as required by the language of appealed
claim 8. Thus, the obviousness rejection of appealed claim 8
fails for lack of an adequate factual basis.
In summary, the examiner’s rejection of appealed claims
14 and 15 under the first paragraph of 35 U.S.C. § 112 is
reversed. The examiner’s rejection of appealed claims 1, 3, 6,
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Application No. 08/115,783
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7, 9, and 14 for obviousness is affirmed. The examiner’s
rejection of appealed claims 4, 5, 8, 13, and 15 for
obviousness is reversed. Accordingly, the decision of the
examiner is affirmed-in-part.
No period for taking any subsequent action in connection
with this appeal may be extended under 37 CFR § 1.136(a).
AFFIRMED-IN-PART
EDWARD C. KIMLIN )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
JOHN D. SMITH ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
CHARLES F. WARREN )
Administrative Patent Judge )
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Application No. 08/115,783
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lp
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CUSHMAN, DARBY & CUSHMAN
1100 NEW YORK AVENUE, N.W.
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WASHINGTON, DC 20005-3918
Leticia
Appeal No. 1996-3121
Application No. 08/115,783
APJ JOHN D. SMITH
APJ WARREN
APJ KIMLIN
DECISION: AFFIRMED-IN-PART
Send Reference(s): Yes No
or Translation (s)
Panel Change: Yes No
Index Sheet-2901 Rejection(s):
Prepared: January 23, 2001
Draft Final
3 MEM. CONF. Y N
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