Ex parte Minato

Board of Patent Appeals and Interferences

Feb 4, 2000

08450145 (B.P.A.I. Feb. 4, 2000)

Application for patent filed May 26, 1995. According to1
appellant, this application is a continuation of Application
08/095,523, filed July 26, 1993, now abandoned; which is a
continuation-in-part of Application 07/912,173, filed July 13,
1992, now abandoned; which is a continuation-in-part of
Application 07/233,823, filed August 10, 1988, now U.S. Patent
No. 5,144,402.
1
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(2) is not binding precedent of the Board.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. 36
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte TADAHARU MINATO
__________
Appeal No. 1997-1757
Application 08/450,1451
__________
HEARD: Jan. 13, 2000
__________
Before KRASS, BARRETT, and BARRY, Administrative Patent
Judges.
KRASS, Administrative Patent Judge.
DECISION ON APPEAL
Appeal No. 1997-1757
Application No. 08/450,145
2
This is a decision on appeal from the final rejection of
claims 5, 7 and 8. Claims 1 through 4 and 6 have been
withdrawn as being directed to a nonelected invention.
The invention is directed to a method of controlling a
carrier lifetime in a semiconductor switching device.
Representative independent claim 5 is reproduced as follows:
5. A transistor having a semiconductor layer with a
current path portion extending substantially from a first
electrode to a second electrode of said transistor through
which a main current flows such that said semiconductor layer
is structured so that the carrier lifetime in said
semiconductor layer is different between substantially all of
said current path portion of said semiconductor layer serving
as a path for most of said main current and a remaining
portion of said semiconductor layer.
The examiner relies on the following reference:
Baliga et al. 4,620,211 Oct. 28, 1986
Claims 5, 7 and 8 stand rejected under 35 U.S.C. § 112,
first and second paragraphs, as being based on an inadequate
written description and being indefinite, respectively.
Further, claims 5, 7 and 8 stand rejected under 35 U.S.C. §
103 as unpatentable over Baliga.
Reference is made to the briefs and answer for the
respective positions of appellant and the examiner.
OPINION
Appeal No. 1997-1757
Application No. 08/450,145
3
Turning first to the rejection under 35 U.S.C. § 112,
first paragraph, the examiner contends that there is no
support for the “carrier lifetime in said semiconductor layer
is different between substantially all of said current path
portion...and a remaining portion of said semiconductor layer”
recited in claims 5, 7 and 8. The examiner’s rationale is
based on appellant’s election of the insulated gate bipolar
transistor in Paper No. 9, such transistor being depicted in
Figures 15A, 15B and 15C, rather than the thyristor depicted
in Figures 3 and 7. Whereas Figures 3 and 7 depict, and
recitations in the specification regarding these figures
describe, the claimed “different” carrier lifetime, Figures
15A, 15B and 15C do not clearly depict the current path
portion, the path for most of the main current and the
remaining portion of the semiconductor and there is no
discussion regarding these elements with regard to Figures
15A, 15B and 15C.
We will not sustain this rejection since we agree with
appellant that Figures 3 and 7, and their attendant
description in the specification, which do, indeed, have
support for the allegedly objectionable claim language,
Appeal No. 1997-1757
Application No. 08/450,145
4
provide teachings which also are applicable to the embodiments
of Figures 15A, 15B and 15C. Moreover, it appears that the
claim language to which the examiner raises the objection was
in the claims as originally filed and an originally filed
claim is its own support. Accordingly, it is difficult to
comprehend how the examiner can contend that there is no
adequate support for the claim language in question.
Turning to the rejection of the claims based on 35 U.S.C.
§ 112, second paragraph, the examiner contends that the claim
language, “substantially all of said current path
portion...serving as a path for most of said main current,” is
vague and indefinite. More particularly, the examiner asks,
at the top of page 4 of the answer, “how can all of the
current path portion have the different carrier lifetime that
[sic, than] the remaining portion of the semiconductor layer”?
The claim language is consistent with the disclosure which
makes it very clear, e.g., see Figure 3, how the current path
portion has a “different carrier lifetime” than the remaining
portion of the semiconductor layer. The current path portion
5 does not have the radiation defects 7 depicted in the
remaining portion of the semiconductor layer. Accordingly, we
Appeal No. 1997-1757
Application No. 08/450,145
5
will not sustain the rejection of claims 5, 7 and 8 under 35
U.S.C. § 112, second paragraph.
Finally, we turn to the rejection of the claims under 35
U.S.C. § 103. The examiner applies Baliga against the instant
claimed subject matter by identifying a semiconductor layer 12
and a first portion 42 of the semiconductor layer which has
defects. This is no different than what appellant has
admitted was known. Then, the examiner concludes that it
would have been obvious “that the carrier lifetime in the
first portion is different from the remaining portion of the
semiconductor layer” [answer, page 5]. The examiner points to
Exhibit A, attached to the answer in order to illustrate the
path for most of the main current and the remaining portion.
However, we find nothing in Baliga suggesting any non-uniform
defects throughout the semiconductor layer and our review of
the examiner’s Exhibit A discloses nothing which would
indicate any such non-uniformity of defects which leads to
different carrier lifetimes between a first portion and a
remaining portion of the semiconductor layer.
With no teaching by Baliga that defects in the
semiconductor layer are applied in any manner but uniformly,
Appeal No. 1997-1757
Application No. 08/450,145
6
it is hindsight reconstruction of the instant claimed subject
matter for the examiner to conclude that Baliga suggests or
makes obvious different carrier lifetimes in two different
portions of the semiconductor layer. The examiner has failed
to establish a prima facie case of obviousness. Accordingly,
we will not sustain the rejection of claims 5, 7 and 8 under
35 U.S.C. § 103.
We have not sustained the rejection of claims 5, 7 and 8
under either 35 U.S.C. § 112, first or second paragraphs, or
under 35 U.S.C. § 103. Accordingly, the examiner’s decision
is reversed.
REVERSED
Errol A. Krass )
Administrative Patent Judge )
)
)
)
Lee E. Barrett ) BOARD OF
PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
Appeal No. 1997-1757
Application No. 08/450,145
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)
)
Lance Leonard Barry )
Administrative Patent Judge )
tdl
Appeal No. 1997-1757
Application No. 08/450,145
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