Ex parte Noble

Board of Patent Appeals and Interferences

Jan 30, 2001

08365617 (B.P.A.I. Jan. 30, 2001)

The opinion in support of the decision being entered today was not written
for publication in a law journal and is not binding precedent of the Board.
Paper No. 39
UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte WENDELL P. NOBLE, JR.
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Appeal No. 1998-3078
Application No. 08/365,617
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ON BRIEF
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Before HAIRSTON, BARRY, and LEVY, Administrative Patent Judges.
BARRY, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal under 35 U.S.C. § 134 from
the rejection of claims 1-15, 24, and 26-28. We reverse.
BACKGROUND
The invention at issue in this appeal relates to dynamic
random access memory (DRAM) cell. A DRAM cell consists of a
transistor and a capacitor, both formed on a semiconductor
substrate, and interconnects formed by a layer of a conductor
on top of the substrate and in contact with the gate of the
Appeal No. 1998-3078 Page 2
Application No. 08/365,617
transistor. Besides the transistor and capacitor, the
substrate level includes a "strap" connecting a given
transistor to a given capacitor and the required isolation
between cells. The interconnect level includes wordlines that
interconnect the gate electrodes of transistors in DRAM cells
and sufficient space between the wordlines to prevent shorting
therebetween. As such, the total area taken up by a given
DRAM cell is determined by the larger of the area of all the
structures on the silicon substrate level and the area of the
connectors and spaces therebetween on the connector level.
Whichever of these two is larger determines the area of the
cell.
The appellant's invention uses segment gates and spacer
wordlines to save area on the connector level of a DRAM cell.
Because the total area of each cell could not be
correspondingly reduced unless the area of each cell at the
silicon substrate level was similarly reduced, the invention
provides a cell design on the silicon level in which a
transistor is adjacent a trench capacitor and formed in
conventional seam-free single crystal silicon using a smaller
Appeal No. 1998-3078 Page 3
Application No. 08/365,617
area on the silicon level than the conventional cell. The
invention further provides a segment gate
and spacer word line integrated with this smaller silicon
level cell design to reduce the area of the whole cell. In
summary, the invention provides a structure having a reduced
cell area because of reductions in area on both levels while
providing the transistor in conventional seam-free single
crystal semiconductor.
Claim 1, which is representative for our purposes,
follows:
1. A semiconductor structure, comprising
a device having a gate, said gate consisting of
an individual segment of gate conductor on a thin
gate dielectric, said device further comprising a
seam-free single crystal semiconductor substrate;
and
a connector on top of and electrically
contacting said segment gate conductor, said
connector being a conductive spacer rail extending
beyond said device.
The references relied on in rejecting the claims follow:
Dhong et al. (Dhong) 5,214,603 May 25,
1993
Appeal No. 1998-3078 Page 4
Application No. 08/365,617
Hayden 5,498,889 Mar. 12,
1996
(filed Dec. 12, 1994).
Claims 1-15, 24, and 26-28 stand rejected under 35 U.S.C. §
103 as obvious over Dhong in view of Hayden. Rather than
repeat the arguments of the appellant or examiner in toto, we
refer the reader to the briefs and answer for the respective
details thereof.
OPINION
In deciding this appeal, we considered the subject matter
on appeal and the rejection advanced by the examiner.
Furthermore, we duly considered the arguments and evidence of
the appellant and examiner. After considering the totality of
the record, we are persuaded that the examiner erred in
rejecting claims 1-15, 24, and 26-28. Accordingly, we
reverse.
We begin by noting the following principles from In re
Rijckaert, 9 F.3d 1531, 1532, 28 USPQ2d 1955, 1956 (Fed. Cir.
1993).
Appeal No. 1998-3078 Page 5
Application No. 08/365,617
In rejecting claims under 35 U.S.C. Section 103, the
examiner bears the initial burden of presenting a
prima facie case of obviousness. In re Oetiker, 977
F.2d 1443, 1445, 24 USPQ2d 1443, 1444 (Fed. Cir.
1992).... "A prima facie case of obviousness is
established when the teachings from the prior art
itself would appear to have suggested the claimed
subject matter to a person of ordinary skill in the
art." In re Bell, 991 F.2d 781, 782, 26 USPQ2d
1529, 1531 (Fed. Cir. 1993) (quoting In re Rinehart,
531 F.2d 1048, 1051, 189 USPQ 143, 147 (CCPA 1976)).
With these principles in mind, we consider the examiner's
rejection. Recognizing that Dhong does not teach a seam-free
substrate, the examiner alleges, "[i]t would have been obvious
to one skilled in this art to form Dhong et al's DRAM cell in
a 'seam-free' single crystal semiconductor substrate as
suggested by Hayden." (Examiner's Answer at 3)
“Obviousness may not be established using hindsight or in
view of the teachings or suggestions of the inventor.”
Para-Ordnance Mfg., 73 F.3d at 1087, 37 USPQ2d at 1239 (citing
W.L. Gore & Assocs., Inc., 721 F.2d at 1551, 1553, 220 USPQ at
311, 312-13 (Fed. Cir. 1983)). “It is impermissible to use
the claimed invention as an instruction manual or ‘template’
Appeal No. 1998-3078 Page 6
Application No. 08/365,617
to piece together the teachings of the prior art so that the
claimed invention is rendered obvious.” In re Fritch, 972
F.2d 1260, 1266, 23 USPQ2d 1780, 1784 (Fed. Cir. 1992) (citing
In re Gordon, 733 F.2d 900, 902, 221 USPQ 1125, 1127 (Fed.
Cir. 1984)). "[T]o establish obviousness based on a
combination of the elements disclosed in the prior art, there
must be some motivation, suggestion or teaching of the
desirability of making the specific combination that was made
by the applicant." In re Kotzab, 217
F.3d 1365, 1370, 55 USPQ2d 1313, 1316 (Fed. Cir. 2000) (citing
In re Dance, 160 F.3d 1339, 1343, 48 USPQ2d 1635, 1637 (Fed.
Cir. 1998) and In re Gordon, 733 F.2d 900, 902, 221 USPQ 1125,
1127 (Fed. Cir. 1984)).

Here, the examiner fails to identify a sufficient reason
to combine Hayden with the Dhong. He merely opines, "[i]t
would have been obvious ... to form Dhong et al's DRAM cell in
a 'seam-free' single crystal semiconductor substrate as
suggested by Hayden." (Id.) Such a broad, conclusory opinion
does not meet the requirement for some motivation, suggestion,
or teaching of the desirability of making the combination.
Appeal No. 1998-3078 Page 7
Application No. 08/365,617
Because there is no evidence that the Hayden's seam-free
substrate would have been desirable in Dhong's DRAM cell, we
are not persuaded that teachings from the prior art would have
suggested the combination. Therefore, we reverse the
rejection of claims 1-15, 24, and 26-28 as obvious over Dhong
in view of Hayden.
CONCLUSION
In summary, the rejection of claims 1-15, 24, and 26-28
stand rejected under 35 U.S.C. § 103 as obvious over Dhong in
view of Hayden is reversed.
REVERSED
Appeal No. 1998-3078 Page 8
Application No. 08/365,617
KENNETH W. HAIRSTON )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
LANCE LEONARD BARRY ) APPEALS
Administrative Patent Judge ) AND
) INTERFERENCES
)
)
)
STUART S. LEVY )
Administrative Patent Judge )
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JAMES M. LEAS
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