Ex Parte Nakamura

Patent Trial and Appeal Board

Jan 31, 2019

14429337 (P.T.A.B. Jan. 31, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
14/429,337 03/18/2015
78198 7590
Studebaker & Brackett PC
8255 Greensboro Drive
Suite 300
Tysons, VA 22102
02/04/2019
FIRST NAMED INVENTOR
Katsumi Nakamura
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
ATTORNEY DOCKET NO. CONFIRMATION NO.
004700-ME0070 8746
EXAMINER
ISAAC, STANETTAD
ART UNIT PAPER NUMBER
2898
NOTIFICATION DATE DELIVERY MODE
02/04/2019 ELECTRONIC
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.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
info@sbpatentlaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KATSUMI NAKAMURA
Appeal2018-003253
Application 14/429,337
Technology Center 2800
Before TERRY J. OWENS, CATHERINE Q. TIMM, and
DEBRA L. DENNETT, Administrative Patent Judges.
DENNETT, Administrative Patent Judge.
DECISION ON APPEAL 1
STATEMENT OF THE CASE
Appellant2 appeals under 35 U.S.C. § 134(a) from a rejection of
claims 20-22. We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.
1 In our Decision, we refer to the Substitute Specification filed March 18,
2015 ("Spec."); the Non-final Office Action dated February 14, 2017 ("Non-
final Act."); the Appeal Brief filed May 25, 2017 ("App. Br."); the
Examiner's Answer dated December 19, 2017 ("Ans."); and the Reply Brief
filed February 2, 2018 ("Reply Br.").
2 Appellant identifies Mitsubishi Electric Corporation as the real party in
interest. App. Br. 2.
Appeal2018-003253
Application 14/429,337
The invention addresses a problem of semiconductor device
manufacture processes being complicated. Spec. ,r 4. An object of the
claimed invention is to provide a semiconductor device capable of
stabilizing electrical characteristics while removing a metal impurity and
other things in a substrate in a simple way, while maintaining the essential
performance of the semiconductor device. Id. ,r 6. Claim 20, reproduced
below from the Claims Appendix, illustrates the claimed subject matter:
20. A semiconductor device comprising:
a substrate having a drift layer;
metal wiring formed on an upper surface of the substrate;
and
an electrode formed on a back surface of the substrate,
wherein the lifetime of carriers in the drift layer satisfies
the following expression 1:
[Expression 1]
T2:l.5xl0-5exp(5.4xl03tN-) ... expression 1
T: the lifetime of carriers in the drift layer [sec]
tN_: the layer thickness of the drift layer [ m]
REFERENCES
The Examiner relies on JP 2011-100890 A to Nakayama Koji,
published May 19, 2011 ("Koji") in rejecting the claims on appeal as
obvious.
2
Appeal2018-003253
Application 14/429,337
REJECTIONS 3
The Examiner maintains and Appellant seeks review of the rejection
of claims 20-22 as failing to comply with the enablement requirement of
35 U.S.C. § 112(a)4; and the rejection of claims 20-22 under 35 U.S.C.
§ 103 over Koji. Non-final Act. 2--4; App. Br. 3-5.
OPINION
Rejection of claims as lacking enablement
We need address only the sole independent claim, i.e., claim 20.The
Examiner finds that the scope of claim 20 is extremely broad, and includes
carrier lifetimes (r) up to infinity. Ans. 3. The Examiner points out that
Appellant's Figure 19 enables only a subset of carrier lifetimes "necessary
for the stabilizing device characteristics, as it pertains to the different
thicknesses of N-drift layer [µm] and setting the carrier lifetime to 1.1x10-4
or larger, which is represented by a straight line in Figure 19," and the
Specification fails to enable carrier lifetimes up to infinity or beyond the
thickness ranges of Figure 19. Id. at 4.
Figure 19 is reproduced below from the '337 Application:
3 In the Answer, the Examiner withdrew the rejection of claims 20-22 as
indefinite under 35 U.S.C. § 112(b). Ans. 2.
4 Because this application was filed after the 16 March 2013, effective date
of the America Invents Act, we refer to the AIA version of the statute.
3
Appeal2018-003253
Application 14/429,337
i~10·-
... . s:
,_ 1'
~
:.;.
' "--C: !U"
l
'
FIG. 19
L~agram showing '-1'U,i<:.·r lik.tiffc ric,::<;;...><;.,sary fix
,;;tabili:dng dcvk~ chara.:;t,:.1-isrics
:' ... ,,··.~i:,·.-,,: ,'
. ',} 100 200 :mo 400 f:iOO GOO i'OO 800
Figure 19 is a diagram showing carrier lifetime necessary for
stabilizing device characteristics. Spec. ,r 11. The carrier lifetime with
which the carrier lifetime dependence of V cE( sat) can be reduced was
calculated with respect to each of values of the layer thickness of the N· drift
layer and the results plotted on the diagram in Figure 19, with the x-axis
being the layer thickness of the N· drift layer in µm and the y-axis being the
carrier lifetime in µsec on a logarithmic scale. See id. ,r 35. For example,
when the layer thickness of the N- drift layer is 400 µm, V cE(sat) can be
stabilized by setting the carrier lifetime to 1.1 x 10-4 seconds or larger. Id.
The lifetimes of carriers in a "device characteristics stabilization region" in
Figure 19 satisfy the equation in claim 20:
T2:l.5xl0-5exp(5.4xl03tN-) ... expression 1
T: the lifetime of carriers in the drift layer [sec]
tN_: the layer thickness of the drift layer [ m]
4
Appeal2018-003253
Application 14/429,337
See id. ,r,r 35-36.
"Although not explicitly stated in section 112, to be enabling, the
specification of a patent must teach those skilled in the art how to make and
use the full scope of the claimed invention without 'undue
experimentation."'. See In re Wright, 999 F.2d 1557, 1561 (Fed. Cir. 1993).
The Examiner bears the initial burden of setting forth a reasonable
explanation as to why the scope of protection provided by a claim is not
adequately enabled in the specification. Id. at 1561-62. Here, the Examiner
does not meet the burden.
During prosecution, an application's claims are given their broadest
reasonable scope consistent with the specification. In re Am. A cad. of Sci.
Tech. Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004). The words used in a claim
must be read in light of the specification, as it would have been interpreted
by one of ordinary skill in the art at the time of the invention. Id. One of
ordinary skill in the art at the time of the invention reasonably would not
have interpreted claim 20 as including infinite carrier lifetimes as concluded
by the Examiner (Ans. 3, 5, 6) which, according to claim 20's Expression 1,
require drift layers of infinite thickness. The skilled artisan would
reasonably infer that limits to the thickness of the drift layers are implicit.
Thus, the claims are not as broad as determined by the Examiner and the
Examiner has failed to provide a reasonable explanation as to why undue
experimentation would be required by the ordinary artisan to make and use
the full scope of semiconductor devices encompassed by the claims as
correctly interpreted.
5
Appeal2018-003253
Application 14/429,337
Appellant's arguments identify reversible error in the Examiner's
rejection. We reverse the Examiner's rejection of claim 20, and, for the
same reasons, the rejection of claims 21 and 22.
Rejection of claims as obvious over Koji
Koji discloses a carrier lifetime of "15 microseconds or more." Koji ,r
27. Thus, Koji teaches the desire for a longer carrier lifetime. However,
Koji does not teach how to accomplish this goal. The Examiner does not
establish that Koji's disclosure of a device with a "carrier lifetime for 15
microseconds or more" and a drift layer thickness of "not less than 300
micrometers," would have indicated to one of ordinary skill in the art how to
produce semiconductor devices that meet the requirements of the expression
in claim 2 0.
The Examiner reversibly errs in concluding that claim 20 is obvious
over Koji. For the same reasons, claims 21 and 22 are not obvious.
The Examiner reversibly errs in concluding that claim 20 is obvious
over Koji. For the same reasons, claims 21 and 22 are also not obvious
DECISION
For the above reasons, the Examiner's rejection of claims 20-22 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)(l )(iv).
AFFIRMED
6