Ex Parte Hower et al

Board of Patent Appeals and Interferences

Mar 31, 2005

10036323 (B.P.A.I. Mar. 31, 2005)

The opinion in support of the decision being entered today was not
written for publication and is not binding precedent of the Board.

UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte PHILIP L. HOWER and TAYLOR R. EFLAND
_____________
Appeal No. 2005-0814
Application No. 10/036,323
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ON BRIEF
_______________
Before CAROFF, PAK, and RUGGIERO, Administrative Patent Judges.
CAROFF, Administrative Patent Judge.
DECISION ON APPEAL
This is a decision on appeal from the examiner’s final
rejection of claims 14, 16 and 18. Claims 27-32 stand withdrawn
from further consideration by the examiner as being drawn to a
non-elected invention. Claim 17, the only other claim now
pending in appellants’ application, stands subject to an
objection but, according to the examiner, would be allowable if
written in independent form.
Appeal No. 2005-0814
Application No. 10/036,323
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The appealed claims are directed to an n-channel DMOS
(“double diffused” metal oxide semiconductor) transistor
structure.
Claim 14, the sole independent claim, is illustrative of the
subject matter embraced by the appealed claims:
14. An n-channel DMOS transistor source structure,
comprising:
an n-type source diffusion, ohmically connected to a
source metallization;
a p-type surface body diffusion which laterally
surrounds at least part of said source diffusion;
a conductive gate structure which is capacitively
coupled to part of said p-type surface body diffusion to
define a channel region therein;
a p-type buried body diffusion which underlies said
channel and at least part of said surface body diffusion;
and
an ohmic connection between said buried body
diffusion and said source metallization;
whereby said buried body diffusion diverts hole
current to bypass said source diffusion, and thereby reduces
emission of secondary electrons, and thereby increases the
safe operating area of the device.
The prior art references relied upon by the examiner are:
Mena et al. (Mena) 4,922,327 May 1, 1990
Huang 6,437,399 B1 Aug. 20, 2002
(effective filing date: Jun. 30, 1997)
Appeal No. 2005-0814
Application No. 10/036,323
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The following prior art reference is cited in appellants’
brief:
Sze, “Basic Device Characteristics,” Physics of Semiconductor
Devices, pp. 433-45, 453-55 (Bell Labs, Inc., 2nd ed., John Wiley
and Sons, New York, 1981).
The following rejections are before us for review:
1. Claim 14 stands rejected under 35 U.S.C. § 102(e) as
being anticipated by Huang.
2. Claims 16 and 18 stand rejected under 35 U.S.C. § 103(a)
for obviousness in view of Huang taken in combination with Mena.
We have carefully considered the entire record in light of
the opposing positions taken by the appellants and by the
examiner. Having done so, we shall affirm both of the rejections
at issue. The basis for our decision is as follows:
The determinative issue in this appeal relates to the scope
to be ascribed to the term “channel region” in claim 14. The
general principle of claim interpretation is that claims in an
application are to be given their broadest reasonable
interpretation consistent with the specification. In re Sneed,
710 F.2d 1544, 1548, 218 USPQ 385, 388 (Fed. Cir. 1983).
The examiner’s view is that “channel region” can be
reasonably construed to include all, or almost all, of the P type
Appeal No. 2005-0814
Application No. 10/036,323
4
base region 14 of Huang (Fig. 12). Indeed, Huang (col. 2, ll. 3-
6) alternatively refers to base region 14 as “the channel
region.”
Appellants, on the other hand, argue that the examiner’s
definition is overly broad, and that only the part of P type base
region 14 of Huang that is directly beneath gate structure 26 can
be considered a channel region. Under this scenario, Huang does
not satisfy the requirement of claim 14 that a p-type buried body
diffusion, i.e., the P+ buried layer 35 of Huang, “underlies said
channel.”
To support their position, appellants rely on Sze. However,
as instructive as Sze may be, we find nothing in Sze which
specifically indicates that when a surface inversion layer (or
channel) forms, it is limited only to the area or region directly
beneath the gate structure. Nor have appellants explained how
this concept necessarily follows from the Sze text.
Neither do we find anything in appellants’ specification
which so specifically defines or limits the boundaries of the
channel region. Nor do appellants offer any explanation as to
how their construction of the claim terminology in question
necessarily follows from the specification.
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Application No. 10/036,323
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Since neither Sze nor appellants’ specification explicitly
defines the physical dimensions or extent of a “channel region,”
we concur with the examiner’s expansive definition which appears
to logically and reasonably follow from Huang’s characterization
of a channel as practically synonymous with exemplified P type
base (channel) region 14.
There is no other dispute with regard to the examiner’s
application of the cited references against claims 14, 16 and 18.
Accordingly, for all of the foregoing reasons, the decision of
the examiner is affirmed.
Appeal No. 2005-0814
Application No. 10/036,323
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No time period for taking any subsequent action in
connection with this appeal may be extended under 37 CFR
§ 1.136(a)(1)(iv).
AFFIRMED
MARC L. CAROFF )
Administrative Patent Judge )
)
)
)
) BOARD OF PATENT
CHUNG K. PAK ) APPEALS AND
Administrative Patent Judge ) INTERFERENCES
)
)
)
)
JOSEPH F. RUGGIERO )
Administrative Patent Judge )
MLC:hh
Appeal No. 2005-0814
Application No. 10/036,323
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