Ex parte Holloway

Board of Patent Appeals and Interferences

Nov 22, 1999

08279135 (B.P.A.I. Nov. 22, 1999)

Application for patent filed Jul. 22, 1994. 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publication in a law journal and (2) is not binding precedent of the Board.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. 12
UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte THOMAS C. HOLLOWAY
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Appeal No. 1997-1034
Application No. 08/279,1351
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ON BRIEF
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Before THOMAS, BARRETT, and DIXON, Administrative Patent Judges.
DIXON, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the Examiner's final rejection of claims 1-6 and
15-20, which are all of the claims pending in this application.
We REVERSE.
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Application No. 08/279,135
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BACKGROUND
The appellant's invention relates to a memory circuit having varied levels of doping
between the pass gate transistors and the pull-down/up transistors. An understanding of
the invention can be derived from a reading of exemplary claim 1, which is reproduced
below.
1. A memory circuit, comprising:
a flip-flop circuit for storing data having first and second pull down
transistors, a gate of each of said pull down transistors having a first predetermined
conductivity level; and
first and second pass gate transistors coupled to said flip-flop, a gate of
each of said pass gate transistors having a second predetermined conductivity
level less than said first predetermined level wherein data is read from and written
to said flip-flop through said pass gate transistors.
The prior art references of record relied upon by the Examiner in rejecting the
appealed claims are:
Klein et al (Klein) 3,673,471 Jun. 27, 1972
Harari 4,132,904 Jan. 02, 1979
Ichinose et al. (Ichinose) 5,020,029 May 28, 1991
Miyaji 5,070,482 Dec. 03, 1991
Claims 1, 3 and 5 stand rejected under 35 U.S.C. § 103 as being unpatentable
over Miyaji and Klein. Claims 1-6, 15-17, 19 and 20 stand rejected under 35 U.S.C.
§ 103 as being unpatentable over Ichinose and Klein. Claim 4 stands rejected under
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Application No. 08/279,135
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35 U.S.C. § 103 as being unpatentable over Miyaji and Klein in view of Harari. Claims 4
and 18 stand rejected under 35 U.S.C. § 103 as being unpatentable over Ichinose and
Klein in view of Harari.
Rather than reiterate the conflicting viewpoints advanced by the Examiner and the
appellant regarding the above-noted rejections, we make reference to the Examiner's
answer (Paper No. 11, mailed Oct. 25, 1996) for the Examiner's reasoning in support of
the rejections, and to the appellant's brief (Paper No. 10, filed May 28, 1996) for the
appellant's arguments thereagainst.
OPINION
In reaching our decision in this appeal, we have given careful consideration to the
appellant's specification and claims, to the applied prior art references, and to the
respective positions articulated by the appellant and the Examiner. As a consequence of
our review, we make the determinations which follow.
“To reject claims in an application under section 103, an Examiner must show an
unrebutted prima facie case of obviousness. See In re Deuel, 51 F.3d 1552, 1557, 34
U.S.P.Q. 2d 1210, 1214 (Fed. Cir. 1995). In the absence of a proper prima facie case
of obviousness, an applicant who complies with the other statutory requirements is entitled
to a patent. See In re Oetiker, 977 F.2d 1443, 1445, 24 U.S.P.Q. 2d 1443,
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Application No. 08/279,135
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1444 (Fed. Cir. 1992). On appeal to the Board, an applicant can overcome a rejection by
showing insufficient evidence of prima facie obviousness or by rebutting the prima facie
case with evidence of secondary indicia of nonobviousness.” In re Rouffet, 149 F.3d
1350, 1355, 47 USPQ2d 1453, 1455 (CAFC 1998). Here, we find that appellant has
overcome the prima facie case of obviousness by showing insufficient evidence by the
Examiner of obviousness.
We find that the Examiner has not made a clear showing of a prima facie case of
obviousness. Furthermore, the Examiner has not clearly addressed the limitations set forth
in claims 1 and 15. The Examiner has applied Mijayi/Ichinose and Klein against the claims
and discussed these references with respect to lowering the “threshold voltage” and
adjustments by doping to adjust the threshold voltage. But the Examiner has not
addressed the language of claims 1 and 15 concerning the “conductivity” of the gate of the
pass gate transistors being lower than the first predetermined conductivity of the pull-down
transistors.
Appellant argues that the Examiner has not shown that the “additional ion
implantation” as taught by Miyaji is directed to the gate of the access transistor as
recited in claim 1. Rather, appellant maintains that this discussion in Miyaji “likely refers to
the threshold adjust implant[ation] into a transistor channel region performed prior to gate
formation.” (See brief at page 3.) We agree with an appellant that the
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Examiner has not clearly shown that the reference teaches that the ion implantation is
made to the gate of the transistors as set forth in the language of claim 1. The Examiner’s
citation to Klein further does not clearly identify that the disclosed teachings are relevant to
use in a memory circuit as recited in claim 1.
Moreover, appellant argues that Klein does not suggest “two different doping levels
for the same gate type in the same integrated circuit. Consequently, Miyaji and Klein do
not suggest the claim 1 requirement to two doping levels of the same type in a single
circuit.” (See brief at page 3.) While this argument goes beyond the express language of
the limitations set forth in claim 1, we agree with the basic premise of appellant's argument
concerning the two different conductivities in the same memory circuit. While Klein
teaches varying the doping of the gate of the transistor, Klein does not expressly teach or
suggest the use of two different doping levels or conductivities on a single integrated
circuit. While Miyaji teaches that the access transistor should have a lower threshold
voltage in the memory circuit, Miyaji is silent with respect to
using two different doping levels or conductivities in the memory. The Examiner has not
provided a convincing line of reasoning why a skilled artisan would have been
motivated to combine the two teachings beyond stating that the electrodes of Miyaji “need
doping in order to perform their function as an electrode, and varying the doping . . . would
have been a very convenient manner of creating the threshold differences
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which Miyaji needs.” (See answers at page 4.) We find that the mere conclusion in
hindsight that the combination would have been “convenient” is not a convincing reason for
the combination.
Appellant analyzes the language of claim 1 with respect to threshold voltage and
argues that “Miyaji proposes the opposite of the claims.” (See brief at page 4.) We agree
with appellant that the combination of the teachings of Miyaji and Klein would not produce
the invention as recited in claim 1. Therefore, we will not sustain the rejection of claim 1
over the combination of Miyaji and Klein nor will we sustain the rejection of dependent
claims 3 and 5.
Similarly, Ichinose teaches that the pull-up transistors have a higher threshold
voltage than the threshold voltage of the access transistors. Therefore, analogous to the
discussion above, the combination of Ichinose and Klein would not teach or
suggest the invention set forth in claim 1 nor its dependent claims 2-6. Since claim 15
contains the same limitations as claim 1 discussed above, we will not sustain the rejection
of claim 15 nor its dependent claims 16, 17, 19 and 20.
The Examiner has not identified any teaching or suggestion in Harari which would
remedy the deficiency discussed above in the combination of Miyaji or Ichinose and Klein.
Therefore, we will not sustain the rejections of claims 4 and 18.
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CONCLUSION
To summarize, the decision of the Examiner to reject claims 1-6 and 15-20 under
35 U.S.C. § 103 is reversed.
REVERSED
JAMES D. THOMAS )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
JOSEPH L. DIXON )
Administrative Patent Judge )
vsh
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Application No. 08/279,135
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STANTON C. BRADEN
TEXAS INSTRUMENTS INC.
P.O. BOX 655474 MS 219
DALLAS, TX 75265