Ex parte OHNO

Board of Patent Appeals and Interferences

Feb 3, 1998

08467650 (B.P.A.I. Feb. 3, 1998)

Application for patent filed June 6, 1995.1
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(2) is not binding precedent of the Board.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. 16
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte YOSHIKAZU OHNO
_____________
Appeal No. 97-3917
Application 08/467,6501
______________
ON BRIEF
_______________
Before FLEMING, LEE and TORCZON, Administrative Patent Judges.
LEE, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from
the final rejection of claims 1-18. No claim has been
allowed.
References relied on by the Examiner
Anand et al. (Anand) 5,111,355 May 5, 1992
Koyama 5,486,713 Jan. 23, 1996
Appeal No. 97-3917
Application 08/467,650
2
(filed May 26, 1995)

Torii et al. (Torii) Japanese Laid Open App. 3-256358
Nov. 15, 1991
Takahashi Japanese Laid Open App. 4-6865
Jan. 10, 1992
Appellant’s stated prior art Figures 5-6.
The Rejections on Appeal
Claims 1-18 stand finally rejected under 35 U.S.C. § 103
as being unpatentable over the appellant’s prior art Figures 5
and 6 in view of Takahashi, Torii, and Koyama.
Claims 1-18 further stand finally rejected under 35
U.S.C.
§ 103 as being unpatentable over the appellant’s prior art
Figures 5 and 6, in view of Takahashi, Torii, Koyama, and
Anand.
With respect to Anand, the examiner states only the
following (answer at 4):
Anand teaches the use of well-known
materials for capacitance use which would
have been obvious to a skilled artisan in
combination with Prior Art Figures 5-6,
Takahashi, Torii, and Koyama.
The Invention
The invention is directed to a semiconductor device
Appeal No. 97-3917
Application 08/467,650
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incorporating capacitors. A first capacitor electrode and a
second capacitor electrode are formed to confront the first
capacitor electrode through a dielectric film. The first
capacitor electrode includes a first-layer electrode and a
second-layer electrode. The second-layer electrode is formed
of a material having a barrier property and has a
circumferential side surface located inner than the side
surface of the first-layer electrode. The dielectric film
contacts the upper and side surface of the first layer
electrode and is "spaced out" from the side surface of the
second layer electrode.
Representative independent claim 1 is reproduced below:
1. A semiconductor device incorporating capacitors
comprising:
a first capacitor electrode;
a capacitor dielectric film; and
a second capacitor electrode formed to confront said
first capacitor electrode with said capacitor dielectric film
interposed therebetween,
said first capacitor electrode including a first-layer
electrode which has an upper and lower surfaces and a
circumferential side surface, and a second-layer electrode
which is formed by being in contact electrically with said
first-layer electrode at the lower surface thereof and has a
circumferential side surface located inner than the side
surface of said first-layer electrode, said second-layer
Appeal No. 97-3917
Application 08/467,650
4
electrode being formed of a material having a barrier
property,
said capacitor dielectric film being in contact with the
upper surface and side surface of said first-layer electrode
an being spaced out from the side surface of said second-layer
electrode.
Opinion
Our opinion is based solely on the arguments raised by
the appellant in his briefs. We do not address and offer no
opinion on arguments which could have been raised but were not
set forth in the briefs.
We sustain the rejection of claims 1-18 over prior art.
The appellant has grouped all claims 1-18 together for
single treatment (Br. at 5). We will discuss claim 1.
As noted above, Anand was relied on by the examiner only
to show specific materials well known for forming the
capacitor. Claim 1 does not require any specific material.
Therefore, we will discuss the rejection based on the admitted
prior art, Takahashi, Torii and Koyama. The discussion would
be equally applicable to the rejection based on the admitted
prior art, Takahashi, Torii, Koyama and Anand.
The distinction of the claimed invention over the
admitted prior art of Figures 5 and 6 is that the second-layer
Appeal No. 97-3917
Application 08/467,650
5
electrode of the first capacitor electrode has a more inner
circumference than the first-layer electrode of the first
capacitor electrode and that the dielectric film is "spaced
out" from the side surface of the second-layer electrode. To
account for this distinction, the examiner relied on
Takahashi.
Takahashi does disclose a capacitor having a first
capacitor electrode including a first-layer electrode and a
second-layer electrode. Also, Takahashi’s second-layer
electrode does have a more inner circumferential side surface
than the side surface of the first-layer electrode. However,
with respect to the claim requirement that the dielectric film
is "spaced out" from the side surface of the second-layer
electrode, the examiner’s reliance on Takahashi is without
support and misplaced.
In the final Office action on page 4 (Paper No. 7), the
examiner states that in Takahashi the dielectric layer 38
"confronts upper side and lower surfaces of the electrode ‘by
being space out therefrom.’" It is unclear just what the
examiner is referring to by "the electrode." To the extent
the examiner is finding that the dielectric layer 38 is
Appeal No. 97-3917
Application 08/467,650
6
"spaced out" from the second-layer electrode 33 by virtue of
being positioned in an abutting relationship as is seen in
Figure 1(f), we disagree.
In the context of the appellant’s claimed invention and
disclosure, "spaced out" from a side surface means separated
from and not contiguous with the side surface of the
electrode. Indeed, as is explained in the specification on
page 5, it is contact between the dielectric film and the side
surface of the lower layer electrode which causes a leakage
current problem.
It is unreasonable to regard Takahashi’s dielectric layer 38
as being "spaced out" from the lower or second-layer electrode
33.
Alternatively, the examiner’s answer sets forth another
view. On page 5 of the answer, it is stated "Takahashi’s
layer 38 provides the ‘spaced out’ function between electrode
37 and dielectric 39.’" However, the position is misplaced
and without merit. In Takahashi, layer 38 is itself the
dielectric layer, not a spacer. Also, as is correctly argued
by the appellant (Reply at 4) layer 39/39a is the other
electrode of the capacitor, not the dielectric film.
Appeal No. 97-3917
Application 08/467,650
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Further on page 5 of the answer, the examiner indicates
that the rejection is not based solely on Takahashi to meet
the "spaced out" claim requirement. The examiner states
"multiple layer dielectrics are well-known in the
semiconductor industry," citing Torii. More specifically, in
the answer on page 4, the examiner relied on Torii and Koyama
as teaching "the use of multiple insulators." The same
statement was made in the final Office action (Paper No. 7) on
page 3. However, we do not read Torii and Koyama as
containing disclosure which can make up for the deficiencies
of Takahashi as already discussed above.
That it was generally known that a single insulator layer
may be replaced by multiple segments of plural insulators does
not provide reasonable motivation for one with ordinary skill
in the art to "space out" a capacitor’s dielectric film from
the lower or second-layer electrode of a first capacitor
electrode. In Torii, the examiner relied (answer at 5) on
multiple insulator segments around the bit line 8 as teaching
the use of multiple insulators where one insulator layer would
be enough. The appellant correctly pointed out that this
feature regarding the isolation of a bit line would not have
Appeal No. 97-3917
Application 08/467,650
8
reasonably suggested the claimed relationship between a
capacitor’s dielectric film and the first-layer and second-
layer electrodes of a capacitor electrode. The claimed
invention is more than using multiple insulator layers in
place of a single insulator layer as an insulator. Torii’s
capacitor, i.e., elements 13-15, do not reflect the claimed
features concerning the dielectric film. As for Koyama, the
examiner states nothing more than that it is relied on to show
the use of multiple insulators. That, of course, is not
sufficient to meet the claim.
As is the case with Torii, Koyama discloses and
reasonably suggests no dielectric layer contacting the upper
and side surfaces of the first-layer electrode 9, which is
also "spaced out" from the side surface of the second-layer
electrode 8. Note also that in Koyama, the second-layer
electrode has a circumferential side surface located outer
than the side surface of the first-layer electrode, not inner
as the appellant claims.
The examiner has, however, taken one position which is
proper and sufficient to support the rejection of claim 1. On
page 5 of the answer in lines 21-24, the examiner stated:
Appeal No. 97-3917
Application 08/467,650
9
Furthermore, even the Prior Art Figures 5 -
6 teach a first portion of electrode 11 and
a second portion 12 wherein dielectric 13
is "spaced out" from small circumference
electrode 11 by insulator 9.
The examiner’s position is reasonable. As is seen in
appellant’s Figure 6, the plug 11 forms a lower or second-
layer electrode and layer 12 forms an upper or first-layer
electrode. The dielectric film 13 contacts the upper and side
surfaces of the upper or first-layer electrode and is spaced
out from the lower or second-layer electrode 11 by insulator
9.
The appellant attempts to rebut the examiner’s position
by stating that claim 1 recites: "a second capacitor electrode
formed to confront said first capacitor electrode with said
capacitor dielectric film interposed therebetween." According
to the appellant, the above-quoted limitation would require
the lower or second-layer electrode of the first capacitor
electrode to be confronting the second capacitor electrode
with a dielectric film in between. We disagree.
The first capacitor electrode still confronts the second
capacitor electrode even if only its first-layer electrode and
not its second-layer electrode is confronting the second
Appeal No. 97-3917
Application 08/467,650
10
capacitor electrode through the dielectric film. Not all of
the first capacitor electrode’s constituent electrode layers
have to be confronting the second capacitor electrode in order
to say that the first capacitor electrode confronts the second
capacitor electrode. Nothing requires reading into claim 1
this "all layers must confront" aspect of the appellant’s
disclosed preferred embodiment to make sense of the claim.
Thus, the feature is extraneous to the claimed invention and
should not be read into the claims. In re Prater, 415 F.2d
1393, 1404,
162 USPQ 541, 550 (CCPA 1969). During patent examination,
claim terms are properly given their broadest reasonable
interpretation consistent with the specification. In re
Zletz, 893 F.2d 319, 321, 13 USPQ2d 1320, 1322 (Fed. Cir.
1989); In re Yamamoto, 740 F.2d 1569, 1571, 222 USPQ 934, 936
(Fed. Cir. 1984).
Note further that in an amendment filed February 5, 1997
(Paper No. 8), the appellant deleted this language from claim
1 concerning the dielectric film: "being formed to confront
the side surface of said second-layer electrode". Thus, it is
not necessary that the second-layer electrode be confronted by
Appeal No. 97-3917
Application 08/467,650
11
the dielectric film. That lends further support to our view
that the second-layer electrode need not confront the second
capacitor electrode through the dielectric film interposed
therebetween.
Conclusion
The rejection of claims 1-18 under 35 U.S.C. § 103 as
being unpatentable over the appellant’s admitted prior art,
Takahashi, Torii, and Koyama is affirmed.
The rejection of claims 1-18 under 35 U.S.C. § 103 as
being unpatentable over the appellant’s admitted prior art,
Takahashi, Torii, Koyama, and Anand 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
Michael R. Fleming )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
Appeal No. 97-3917
Application 08/467,650
12
Jameson Lee )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
Richard Torczon )
Administrative Patent Judge )
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