Ex parte WANG

Board of Patent Appeals and Interferences

Aug 6, 1998

08179887 (B.P.A.I. Aug. 6, 1998)

Application for patent filed January 10, 1994. 1
According to appellant, this application is a continuation of
Application 07/901,351, filed June 19, 1992.
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(2) is not binding precedent of the Board.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. 24
UNITED STATES PATENT AND TRADEMARK OFFICE
__________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
__________
Ex parte PATRICK C. WANG1
__________
Appeal No. 96-0665
Application 08/179,887
__________
ON BRIEF
__________
Before HAIRSTON, KRASS, and JERRY SMITH, Administrative Patent
Judges.
KRASS, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the final rejection of
claim 16. Claims 17 through 21, the only other pending claims,
have been indicated as being directed to allowable subject matter
and are no longer before us on appeal.
Appeal No. 96-0665
Application No. 08/179,887
2
The invention pertains to a single polysilicon layer flash
E2PROM cell, the nature of which is best illustrated by reference
to independent claim 16, reproduced as follows:
16. An E PROM cell comprising:2
a substrate of a first conductivity type having source,
drain and control gate regions of a second conductivity type
disposed along a surface of the substrate and extending into the
substrate, the source and drain regions defining a channel region
therebetween and being separated from the control gate region;
an oxide layer formed on the surface of the substrate and
having portions located over the source, drain, channel and
control gate regions; and
a floating gate formed over the oxide layer and comprising
polysilicon, the floating gate being part of the only layer of
the cell containing polysilicon, the floating gate consisting
solely of:
a first portion located over the control gate region;
and
an elongated second portion including:
a first part located over portions of the source
and drain regions and over the channel region, and
a second part connected between the first portion
and the first part.
The examiner relies on the following reference:
Adam 4,425,631 Jan. 10, 1984
Claim 16 stands rejected under 35 U.S.C. § 102(b), or,
alternatively, 35 U.S.C. § 103, as being anticipated by, or
obvious over, Adam.
Appeal No. 96-0665
Application No. 08/179,887
3
Reference is made to the briefs and answer for the
respective positions of appellant and the examiner.
OPINION
We affirm.
The examiner sets forth his reasoning regarding the
rejection of claim 16, at pages 2-3 of the answer. Appellant
makes only two arguments regarding the instant claim limitations
vis à vis that which is disclosed by Adam. First, appellant
argues that claim 16 distinguishes over the embodiments of Figs.
3, 4 and 5 of the reference because of the claimed negative
limitation of the floating gate structure “consisting solely of
. . .” Second, appellant argues that with regard to Adam’s Fig.
5, the n+-doped source/erase region 25 and drain/write region 16
have different conductivity type than the p+-doped diffusion
region 4 while claim 16 calls for the source, drain and control
gate regions to be all of the same conductivity type.
Addressing appellant’s first argument, we have no problem
with negative limitations appearing in the claim. However, we do
not view the claim language to be as restrictive as appellant
apparently believes the language to be.
We apply the claim language of interest to Figure 5 of Adam,
as depicted on page 4 of the reply brief. Identifying the
Appeal No. 96-0665
Application No. 08/179,887
Note that this “first portion” is located over the2
control gate region, as shown by appellant at page 4 of the reply
brief.
4
floating gate in Adam as Fg, it is seen that the floating gate
“consisting solely” of “a first portion” (say, beginning from the
line going through the label “Fg” in Adam’s Fig.5 as depicted on
page 4 of the reply brief and extending to the right all the way
to the end of the floating gate) ; and an elongated portion2
including “a first part” (as depicted by appellant in the
annotated Fig. 5 at page 4 of the reply brief) located over
portions of the source and drain regions and over the channel
region, and a “second part” (that portion indicated by appellant
as the “second part between first part and first portion” on the
annotated Fig. 5 at page 4 of the reply brief). Accordingly,
Fig. 5 (as well as either one of Figs. 3 or 4, for similar
reasons) of Adam does, indeed, disclose the subject matter of
claim 16.
Now, appellant focuses on the portion of Fg, in Adam, which
overlies diffusion region 4 and contends that this cannot be the
claimed “second part” because it does not lie between the first
part and the first portion. We agree. However, there is nothing
Appeal No. 96-0665
Application No. 08/179,887
A possible problem may arise, however, in that it is not3
all that clear whether what appellant intended is supported by
the disclosure. For example, viewing appellant’s Fig. 5, as
depicted by appellant at the top of page 4 of the reply brief,
the top portion of first portion 168 appears to overlie more than
control gate region 142 and the very top of the first part of the
elongated second portion appears to go a bit further than the end
of the source and drain regions 138, 140. Thus, it would appear
that appellant’s own disclosure suggests that the floating gate
may, in fact, extend beyond the doped regions of the source,
drain and control gate regions, contrary to what appellant argues
[principal answer - page 10] as his intent.
5
in the claim which precludes this portion of Fg from being part
of the claimed “first portion.”
We understand that appellant intended to limit the claim
such that only doped regions overlain by the floating gate are
the source, drain and control gate regions and that the floating
gate should not extend beyond these areas to cover additional
doped regions (such as region 4 in Adam) [see page 10 of the
principal brief]. If the claim included such limitations, we
would agree that this would distinguish over that which is taught
by Adam. Unfortunately, this is not what the language of claim3
16 requires. According to the claim language, the floating gate
is “consisting solely” of a first portion and an elongated second
portion, the second portion having a first and second part, as
claimed. This much is shown by Adam. Contrary to appellant’s
intent, there is nothing in the claim which precludes the first
Appeal No. 96-0665
Application No. 08/179,887
6
portion from being located over the control gate region and also
some other region such as region 4 of Adam.
Turning now to appellant’s second argument, claim 16
requires a substrate of a first conductivity type. Adam shows a
substrate 3 of p-conductivity type. Claim 16 also requires the
source, drain and control gate regions to be of a second
conductivity type. Adam shows source, drain and control gate
regions to be of n-conductivity type. Thus, Adam clearly meets
the claim language. There is nothing in the claim which
precludes some other region, e.g., diffusion region 4 of Adam,
from being of a first conductivity type and, as explained supra,
there is nothing in the claim which precludes Adam’s diffusion
region 4 at all. Accordingly, appellant’s arguments are not
persuasive.
The examiner’s decision rejecting claim 16 under 35 U.S.C.
§§ 102(b)/103 is affirmed.
Appeal No. 96-0665
Application No. 08/179,887
7
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
)
)
Jerry Smith )
Administrative Patent Judge )
Appeal No. 96-0665
Application No. 08/179,887
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Paul J. Winters
Skjerven, Morrill, Macpherson,
Franklin & Friel
25 Metro Drive, Suite 700
San Jose, CA 95110