Ex parte Tserng et al.

Board of Patent Appeals and Interferences

Mar 31, 2000

08089359 (B.P.A.I. Mar. 31, 2000)

Application for patent filed July 9, 1993, entitled1
"Integrated Circuit Capable Of Low-Noise And High-Power
Microwave Operation," which is a division of Application
07/973,906, filed November 10, 1992, now U.S. Patent
5,254,492, issued October 19, 1993.
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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journal and (2) is not binding precedent of the Board.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. 17
UNITED STATES PATENT AND TRADEMARK OFFICE

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES

Ex parte HUA Q. TSERNG
and PAUL SAUNIER

Appeal No. 1997-3484
Application 08/089,3591

ON BRIEF

Before JERRY SMITH, BARRETT, and LALL, Administrative Patent
Judges.
BARRETT, Administrative Patent Judge.
Appeal No. 1997-3484
Application 08/089,359
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DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 1-5. Claims 6-10 are
indicated to be allowable. Claims 20-28 stand withdrawn
pursuant to a restriction requirement.
We reverse.
BACKGROUND
The disclosed invention is directed to an integrated
circuit with two different types of field effect transistors
which eliminates the need for epitaxial regrowth.
Claim 1 is reproduced below.
1. An integrated circuit for providing low-noise and
high-power microwave operation comprising:
a material structure comprising:
a substrate;
a low-noise channel layer;
a low-noise buffer layer;
a power channel layer; and
a wide bandgap layer;
a first active region comprising:
a first source contact above said wide bandgap
layer;
Appeal No. 1997-3484
Application 08/089,359
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a first drain contact above said wide bandgap
layer, wherein said first source contact and said first
drain contact are alloyed and thereby driven into said
material structure to make contact with said low-noise
channel layer; and
a first gate contact to said low-noise buffer
layer; and
a second active region comprising:
a second source contact above said wide
bandgap layer;
a second drain contact above said wide bandgap
layer, wherein said second source contact and said
second drain contact are alloyed and thereby driven
into said material structure to make contact with said
power channel layer; and
a second gate contact to said wide band-gap
[sic] layer;
wherein said first active region and said second
active region are electrically isolated from one
another.
The Examiner relies on the following prior art:
Itoh 4,866,490 September 12,
1989
Takikawa 5,302,840 April 12, 1994
(filed June 17, 1992)
Claims 1 and 3-5 stand rejected under 35 U.S.C.
§ 102(e) as anticipated by, or in the alternative, under
35 U.S.C. § 103 as being unpatentable over Takikawa.
Appeal No. 1997-3484
Application 08/089,359
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Claim 2 stands rejected under 35 U.S.C. § 103 as being
unpatentable over Takikawa and Itoh.
We refer to the Final Rejection (Paper No. 7) and the
Examiner's Answer (Paper No. 14) (pages referred to as
"EA__") for a statement of the Examiner's position and to
the Amended Appeal Brief (Paper No. 16) (pages referred to
as "Br__") for a statement of Appellants' arguments
thereagainst.
OPINION
Initially, we conclude that the Examiner erred in the
claim interpretation that nothing in claim 1 prevents using
different labels on different halves of the structure in
Takikawa. It is true that the claimed "material structure"
comprising a substrate and four layers, by itself, does not
positively require that the layers are coextensive with each
other over the whole area of the substrate and does not
recite the order of the layers. If it were just this
limitation at issue, we would agree that it is only
necessary that there be a structure corresponding to the
substrate and the four layers; e.g., one region could have a
substrate, a low-noise channel layer, and a wide bandgap
Appeal No. 1997-3484
Application 08/089,359
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layer and a second region could have a substrate, a
power-channel layer, and a wide bandgap layer. The same
planar layer in Takikawa could have different functions in
the different regions because the regions are separated by
an isolation region 11. Of course, the same planar region
on the same side of the isolation region 11 cannot have
different functions. However, the Examiner's interpretation
fails to account for the language that both the first source
and drain contacts and second source and drain contacts are
recited to be "driven into said material structure," which
requires the same "material structure" in both active
regions, not just parts of this structure.
The Examiner makes at least three errors.
First, Takikawa does not disclose the same four layers
in the two different regions and, therefore, does not
disclose that the contacts are "driven into said material
structure."
Second, we agree with Appellants' argument (Br4) that
Takikawa does not disclose "a first gate contact to said
low-noise buffer layer." The Examiner relies on potential
barrier layer 5 in Takikawa as the wide bandgap layer in
Appeal No. 1997-3484
Application 08/089,359
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order to meet the limitations of "a first source contact
above said wide bandgap layer," "a first drain contact above
said wide bandgap layer," "a second source contact above
said wide bandgap layer," "a second drain contact above said
wide bandgap layer," and "a second gate contact to said wide
band-gap [sic] layer." The Examiner finds the region above
the p-channel region 3H to be the low-noise buffer layer
(EA2) and considers the region with the plus signs in
circles underlying the gate 12 as part of the gate contact
with electrode 12 (EA5). However, this is an unreasonable
distortion of Takikawa since gate electrode 12 is separated
from the layer 4 above region 3H by layer 5 and, thus, there
is no contact "to" this layer 4. above region 3H. The layer
5 is a potential barrier which is doped with impurities to
retain ionized charges (indicated by the plus signs in
circles) which shift the threshold voltage of the HEMT
toward negative (col. 5, line 62 to col. 6, line 2) and is
not part of the gate contact. Takikawa does not disclose "a
first gate contact to said low-noise buffer layer."
Third, claim 1 does not teach alloyed source and drain
contacts because, as noted by Appellants (Br4), Takikawa
Appeal No. 1997-3484
Application 08/089,359
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discloses forming source and drain contacts on p-type
regions 6 and 6 and n-type regions 8 and 9. Thus, the
anticipation rejection is improper. The Examiner states
(EA3-4): "Alternatively, it would have been obvious to
alloy the contacts with the underlying material in order to
obtain ohmic contacts." The Examiner cites no evidence to
support this conclusion. "Even if obviousness of the
variation is predicated on the level of skill in the art,
prior art evidence is needed to show what that level of
skill was." In re Kaplan, 789 F.2d 1574, 1580,
229 USPQ 678, 683 (Fed. Cir. 1986). "Assertions of
technical facts in areas of esoteric technology must always
be supported by citation to some reference work recognized
as standard in the pertinent art." See In re Ahlert, 424
F.2d 1088, 1091, 165 USPQ 418, 420 (CCPA 1970); accord In re
Pardo, 684 F.2d 912, 917, 214 USPQ 673, 677 (CCPA 1982).
See also In re Eynde, 480 F.2d 1364, 1370, 178 USPQ 470, 474
(CCPA 1973) (court will not take judicial notice of the
state of the art). Regardless of what we may know
personally, there is no evidence to support the Examiner's
bare conclusion in any further judicial review.
Appeal No. 1997-3484
Application 08/089,359
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Accordingly, the Examiner has failed to provide sufficient
evidence to support a prima facie case of obviousness.
For the reasons stated above, the anticipation and
obviousness rejections of claims 1 and 3-5 are reversed.
The Itoh patent does not cure the deficiencies of Takikawa
with respect to the rejection of claim 1. Accordingly, the
rejection of claim 2 is also reversed.
REVERSED
JERRY SMITH )
Administrative Patent Judge )
)
)
)
) BOARD OF
PATENT
LEE E. BARRETT ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
PARSHOTAM S. LALL )
Administrative Patent Judge )
Appeal No. 1997-3484
Application 08/089,359
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Michael K. Skrehot
P.O. Box 655474, M/S 219
Dallas, TX 75265