Ex parte SMOOHA

Board of Patent Appeals and Interferences

Jun 11, 1998

08118109 (B.P.A.I. Jun. 11, 1998)

Application for patent filed September 8, 1993.1
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(2) is not binding precedent of the Board.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. 14
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte YEHUDA SMOOHA
_____________
Appeal No. 95-2859
Application 08/118,1091
______________
ON BRIEF
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Before JERRY SMITH, FLEMING and LEE, Administrative Patent
Judges.

LEE, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision under 35 U.S.C. § 134 from the final
rejection of claims 1-6. Claims 7-11 have been withdrawn from
consideration. No claim has been allowed.
References relied on by the Examiner
Morris et al. (Morris) 4,830,976 May 16, 1989
Appellant’s admitted prior art of Figures 1-3
Appeal No. 95-2859
Application 08/118,109
2
The Rejections on Appeal
Claims 1-6 stand finally rejected under 35 U.S.C. § 103 as
being unpatentable over the appellant’s own admitted prior art of
Figures 1-3 in view of Morris.
The Invention
The invention is directed to an integrated circuit including
a field effect transistor and a resistor. The gate of the
transistor is formed from a conductor layer and the resistor is
formed in a tub region of the same conductivity type as the
source and drain of the transistor. The resistor underlies a
"resistor masking conductor" formed from the conductor layer
also forming the gate of the transistor. Claim 1 is the only
independent claim and is reproduced below.
1. An integrated circuit including a field effect
transistor having a gate conductor formed from a conductor layer
overlying a semiconductor body, and having a source/drain region
of a given conductivity type that is coupled to a circuit
conductor through a resistor,
characterized in that said resistor is formed in a tub
region of said given conductivity type, with said tub region
being connected to said circuit conductor by means of a heavily
doped contact region of said given conductivity type that is
formed in said tub region;
and wherein said resistor underlies a resistor masking
conductor formed from said conductor layer, whereby the size of
said resistor is defined by said resistor masking conductor.
Appeal No. 95-2859
Application 08/118,109
3
Opinion
We do not sustain the rejection of claims 1-6 under 35
U.S.C. § 103 as being unpatentable over the appellant’s own
admitted prior art of Figures 1-3 in view of Morris.
The determinative issue is whether Morris discloses a
resistor which underlies a "resistor masking conductor" formed
from a conductor layer also forming the gate of a transistor. In
the appellant’s own admitted prior art of Figures 1 and 2, the
resistor underlies either field oxide 107 (Figure 1) or deposited
oxide region 212 and grown oxide region 211 (Figure 2). That
does not satisfy the claimed feature of having a resistor which
underlies a resistor masking conductor made from the same
conductor layer forming the gate of the transistor. The examiner
is relying on Morris to fill this deficiency in the appellant’s
own admitted prior art. (Answer at page 3).
Morris does disclose use of a polysilicon layer for forming
the gate of the transistor as well as a mask for forming the
resistor. However, in Morris the formed resistor does not
"underlie" the polysilicon mask. Indeed, with reference to
Appeal No. 95-2859
Application 08/118,109
4
Figure 11 of Morris, the width of the formed resistor is defined
as that corresponding to the open area exposed or not covered by
the polysilicon mask. See column 7, lines 45-47. Thus, we agree
with the appellant that in Morris the resistor does not underlie
a “resistor masking conductor” as is called for by appellant’s
claim 1.
Alternatively, even if one were to regard the edges of the
p+ doped area in Morris which are underneath the polysilicon as
a part of the resistor, contrary to the express indication in
Morris, that is not sufficient to support a characterization
of the resistor element, in its role as an operative part, as
"underlying" the polysilicon mask. In Morris it is clear that
the resistor primarily occupies that open area exposed or
uncovered by the polysilicon mask. The p+ doped portions outside
of the exposed area do not meaningfully contribute to the
resistance of the resistor. To the extent that the examiner is
of the view that if any area making a contribution, however
small, to the overall resistance is under the mask, then the
resistor can be deemed as underlying the mask, we disagree.
That view is unreasonable and cannot be upheld.
Appeal No. 95-2859
Application 08/118,109
5
Applying the masking procedure of Morris to the prior art
acknowledged by the appellant would not result in the claimed
invention, because of the different manner in which the mask is
employed in Morris and in the admitted prior art. Moreover,
because of the difference in application, one with ordinary skill
in the art would have no reasonable motivation to simply replace
the oxide mask of the admitted prior art with the polysilicon
mask disclosed in Morris.
For the foregoing reasons, we do not sustain the rejection
of claims 1-6 under 35 U.S.C. § 103 as being unpatentable over
the appellant’s own admitted prior art in view of Morris.
Conclusion
The rejection of claims 1-6 under 35 U.S.C. § 103 as being
unpatentable over the appellant’s own admitted prior art of
Figures 1-3 in view of Morris is reversed.
REVERSED
JERRY SMITH )
Administrative Patent Judge )
Appeal No. 95-2859
Application 08/118,109
6
)
)
) BOARD OF PATENT
MICHAEL R. FLEMING )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
JAMESON LEE )
Administrative Patent Judge )
Appeal No. 95-2859
Application 08/118,109
7
P.V.D. Wilde
AT&T Bell Laboratories
600 Mountain Avenue
P.O. Box 636
Murray Hill, NJ 07974-0636