Ex parte LIU et al.

Board of Patent Appeals and Interferences

Mar 5, 1998

08251011 (B.P.A.I. Mar. 5, 1998)

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(2) is not binding precedent of the Board.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. 26
UNITED STATES PATENT AND TRADEMARK OFFICE
_______________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_______________
Ex parte MICHAEL S. LIU
and JAMES C. LAI
_______________
Appeal No. 97-1387
Application 08/251,0111
_______________
ON BRIEF
_______________
Before HAIRSTON, KRASS, and FLEMING, Administrative Patent
Judges.
KRASS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the final rejection of
claims 1 through 4. Claims 5 through 102 have been indicated
by the examiner as being directed to allowable subject matter
and are not on appeal before us.

1 Application for patent filed May 31, 1994. According to
appellants, this application is a continuation of Application
07/997,864, filed December 29, 1992, now abandoned.
2 A rejection of claims 6 and 8 through 10 under 35 U.S.C.
Appeal No. 97-1387
Application No. 08/251,011
2
The invention is directed to a semiconductor device as
set forth in independent claim 1, reproduced as follows:
1. A semiconductor device comprising:
a support structure formed of an electrically insulating
layer on a semiconductor material base of a first conductivity
type;
a plurality of field-effect transistors including first
and second field-effect transistors comprising:
first and second semiconductor material substrates for
said first and second field-effect transistors, respectively,
that are substantially crystalline and provided spaced apart
from one another on said electrically insulating layer with
each having a central portion thereof of said first
conductivity type, said first semiconductor material substrate
having a pair of terminating regions of said first
conductivity type separated by said central portion thereof
each having a greater conductivity than said central portion,
said second semiconductor material substrate having a pair of
terminating regions of a second conductivity type separated by
said central portion thereof;
first and second gate oxide layers provided on at least
said first and second semiconductor material substrate central
portions, respectively; and
first and second gate semiconductor structures of a
common conductivity type provided on said first and second
gate oxide layers across from said first and second
semiconductor material substrate central portions,
respectively.
The examiner relies on the following references:

' 112, second paragraph, was withdrawn by the examiner in the
answer.
Appeal No. 97-1387
Application No. 08/251,011
3
Hayashi 2-200603 Jan. 23, 1990
Malhi et al. (Malhi), “Novel SOI CMOS Design Using Ultra Thin
Near Intrinsic Substrate,” IEDM 82, pp. 107-10, 1982.
Whitlow et al. (Whitlow), “Mass-dispersive recoil spectrometry
studies of oxygen and nitrogen redistribution in ion-beam-
synthesized buried oxynitride layers in silicon,” App. Phys.
Lett., vol. 52, no. 22, pp. 1871-73, 1988.
Claims 1 through 4 stand rejected under 35 U.S.C. ' 103.
As evidence of obviousness, the examiner cites Hayashi in view
of Malhi with regard to claims 1, 2 and 4, adding Whitlow to
this combination with regard to claim 3.
Reference is made to the brief and answer for the
respective positions of appellants and the examiner.
OPINION
With regard to independent claim 1, the examiner takes
the position that Hayashi, in Figure 5, discloses all that is
claimed [see page 4 of the answer] but for a showing of
forming the insulating substrate 102 formed on a p-type
silicon supporting substrate. The examiner reasons that since
Malhi shows a complementary type thin film FET, as does
Hayashi, but shows the transistor formed on an insulating
substrate which is then formed on a p-type Si substrate

3 Our understanding of Hayashi is based on an English
translation thereof prepared by the United States Patent and
Appeal No. 97-1387
Application No. 08/251,011
4
[Figure 5 of Malhi], it would have been obvious “to have the p
type silicon supporting substrate of Malhi…in Hayashi because
it is a widely use [sic, used] supporting material for [a]
thin film transistor” [answer, page 5].
While the examiner’s rationale appears reasonable, on its
face, appellants make the following arguments:
1. Combining Hayashi and Malhi would defeat the purpose of
Hayashi’s structure which is intended as a display
device switch. Therefore, a wafer substrate positioned
as articulated by the examiner “would block the view of
the display thereabove” [brief-page 12].
2. The polysilicon transistors of Hayashi would not result
if the fabrication process started with the crystalline
semiconductor material wafer used by Malhi since the
point of starting with a crystalline material is to
provide crystalline substrate transistors.
3. Hayashi does not disclose the FETs required by
independent claim 1, i.e., that they be “substantially
crystalline.” On the contrary, Hayashi’s transistors
are formed in polycrystalline substrates.

Trademark Office. A copy of the translation is attached
hereto.
Appeal No. 97-1387
Application No. 08/251,011
5
Regarding appellants’ first argument, we are not
persuaded that the combination of the Hayashi and Malhi
teachings would defeat the purpose of Hayashi’s structure
“intended as a display device switch” because we find no
evidence that that is the purpose of Hayashi. While
appellants make the allegation that the intended purpose of
Hayashi’s structure is a display device switch, appellants
have not pointed to anything in Hayashi which provides
evidence of this purpose, the examiner concludes that the
English translation of Hayashi never discloses the device of
Figure 5 to be intended for use in a display device and our
independent review of the English translation leads us to the
same conclusion. Accordingly, without some evidence that
Hayashi discloses what appellants allege it discloses
regarding the structure’s use in a display device, appellants’
argument in this regard is simply not persuasive.
Moving on to appellants’ second argument, just because
Malhi may start with a crystalline material in order to
provide crystalline substrate transistors, this does not lead,
inescapably, to the conclusion that the only reason the
artisan would ever start with a crystalline material is to
provide crystalline substrate transistors. As the examiner
Appeal No. 97-1387
Application No. 08/251,011
6
points out at page 6 of the answer, at the end of the only
full paragraph, “it is possible to form polycrystalline
silicon transistors of Hayashi on the insulator-semiconductor
substrate of Malhi” and it was “well known in the art that
single crystalline silicon can be recrystallized” by various
methods. Now, we realize that merely because something is
possible or can be done does not make it obvious within the
meaning of 35 U.S.C. ' 103. However, it is our view that the
examiner was merely pointing out that the polysilicon
transistors of Hayashi may very well be produced starting from
a single crystalline material as a support structure and this
is never denied by appellants, appellants’ only argument in
this regard being that “the very point of forming such a
structure is to provide crystalline substrate transistors”
[brief-page 12]. Yet, while one reason for employing a single
crystalline material base may be to provide crystalline
substrate transistors, this may not be the sole reason. There
may be a number of reasons why the artisan would employ a
single crystalline material base and yet still prefer to
provide polycrystalline silicon transistors, based on various
characteristics of the materials and the desired goals.
Appeal No. 97-1387
Application No. 08/251,011
7
Therefore, we find appellants’ second argument to be
unpersuasive.
Turning to the third argument, we, again, agree with the
examiner. The term “substantially crystalline” is overly
broad. Perhaps appellants intended to use the term
“substantially monocrystalline.” As claimed, and argued,
however, it would appear to us that whether a material was
monocrystalline or polycrystalline, it would still be
“substantially crystalline.” Accordingly, for appellants to
argue that claim 1 requires that the first and second
semiconductor material substrates used in forming the FETs are
“substantially crystalline” while the transistors in Hayashi’s
Figure 5 are formed in a “polycrystalline substrate” is not
persuasive since the “polycrystalline substrate” of Hayashi
is, indeed, “substantially crystalline.” The polycrystalline
substrate of Hayashi may not be monocrystalline but it is
clearly “substantially crystalline,” as claimed. If there is
a convention in the art or a definition in the instant
disclosure which equates “crystalline” with “monocrystalline,”
appellants have not alluded to any evidence which would
indicate this to be the case and we are unaware of any such
convention or definition.
Appeal No. 97-1387
Application No. 08/251,011
8
Our interpretation of “substantially crystalline” would
also be applicable to appellants’ second argument as an
alternative reason for finding that argument to be
unpersuasive. In other words, since “crystalline,” or
“substantially crystalline” covers both monocrystalline and
polycrystalline materials, appellants’ argument, that
polysilicon transistors would not result if the fabrication
process starts with a “crystalline” semiconductor material
wafer, would appear to be in error since the “crystalline”
semiconductor material wafer may be monocrystalline or
polycrystalline.
Appellants’ comments with regard to the background
section of the Sarma patent, of record, at page 13 of the
brief, are not persuasive since they are directed to things
outside the scope of claim 1. Similarly, the argument at
page 14 of the brief regarding “dimensional mismatch” is not
persuasive since claim 1 indicates no particular dimensions
and Hayashi does not appear to be directed, or limited, to
display devices, as contended by appellants.
Contrary to appellants’ contention, we fail to find any
reason why Malhi and Hayashi would not be combinable. They
are both directed to complementary type thin film field-effect
Appeal No. 97-1387
Application No. 08/251,011
9
transistors formed on insulating substrates and the artisan
clearly would have been led to employ the supporting substrate
of Malhi in Hayashi since, as the examiner contends, it would
appear that the supporting substrate of Malhi is “a widely use
[sic, used] supporting material for [a] thin film transistor”
[answer-top of page 5].
Since appellants do not argue the merits of dependent
claims 2 through 4 separate from independent claim 1, claims 2
through 4 will fall with claim 1.
Accordingly, the examiner’s decision rejecting claims 1
through 4 under 35 U.S.C. ' 103 is affirmed.
No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
' 1.136 (a).
AFFIRMED
Kenneth W. Hairston )
Administrative Patent Judge )
)
)
)
Errol A. Krass ) BOARD OF PATENT
Administrative Patent Judge ) APPEALS AND
) INTERFERENCES
)
)
Michael R. Fleming )
Appeal No. 97-1387
Application No. 08/251,011
10
Administrative Patent Judge )
Appeal No. 97-1387
Application No. 08/251,011
11
Gregory A. Bruns
Honeywell Inc.
P.O. Box 524
Minneapolis, MN 55440