Ex Parte Mathew et al

Patent Trial and Appeal Board

Mar 28, 2013

11257973 (P.T.A.B. Mar. 28, 2013)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE PATENT TRIAL AND APPEAL BOARD
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Ex parte LEO MATHEW and RODE R. MORA
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Appeal 2010-008999
Application 11/257,9731
Technology Center 2800
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Before JOSEPH F. RUGGIERO, MARC S. HOFF, and JEFFREY S.
SMITH, Administrative Patent Judges.

HOFF, Administrative Patent Judge.

DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134(a) from a final rejection of
claims 1-11.2 We have jurisdiction under 35 U.S.C. § 6(b).
We reverse.

1 The real party in interest is Freescale Semiconductor Inc.
2 Claims 12-21 stand withdrawn as being directed to a nonelected invention.
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Application 11/257,973

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STATEMENT OF THE CASE
Appellants’ invention is a FinFET made with a lateral extension of the
channel so as to increase its current drive. The fin is formed by an etch that
leaves, in addition to the fin, a floor of semiconductor material that is left
over the substrate. Width of the later extension is adjustable from 50 to 1000
Angstroms. The increased current drive is selectable but not limited to
increments corresponding to the fin height (Spec. 3).
Independent claim 1, reproduced below, is representative of the
subject matter on appeal.
1. A method for creating an inverse T field effect transistor,
comprising:

creating a horizontal semiconductor region and a vertical active region
on a substrate, wherein the horizontal semiconductor region is on a top
surface of a substrate, wherein the top surface of the substrate is an electrical
insulator;

forming a sidewall spacer on a first side of the vertical active region
and over a first part of the horizontal semiconductor region adjacent to the
first side and leave an exposed first portion of the horizontal semiconductor
region adjacent to the first part, and on a second side of the vertical active
region and over a second part of the horizontal semiconductor region
adjacent to the second side and leave an exposed second portion of the
horizontal active region adjacent to the second part, wherein the first part is
a first horizontal active region and the second part is a second horizontal
active region;

etching away the first portion and the second portion of the horizontal
active region through to the top surface of the substrate to leave the first
horizontal active region and the second horizontal active region;

removing the sidewall spacer;

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Application 11/257,973

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forming a gate dielectric over the first horizontal active region, the
second horizontal active region, and at least a first part of the vertical active
region;

forming a gate electrode over the gate dielectric; and

forming a source region and a drain region in portions of the first and
second horizontal active regions and the vertical active region.

REFERENCES
Hu US 6,413,802 B1 Jul. 2, 2002
Lee US 2005/0035391 A1 Feb. 17, 2005
REJECTION
Claims 1-11 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over Hu in view of Lee.
ISSUE
Appellants argue, inter alia, that neither Lee nor Hu teaches a process
that results in a horizontal active region (App. Br. 11). Appellants contend
that the small horizontal portion 112 of the substrate in Lee is masked, and is
not part of the channel; as a result, the small horizontal portion is not part of
the active region (Id.).
The Examiner finds that Lee teaches etching away the first portion of
the horizontal semiconductor region to leave the first horizontal active
region and the second horizontal active region (Ans. 4). The Examiner
further states, however, that “[w]hether or not the horizontal portion of the
inverted ‘T’ structure is active is irrelevant to the process as claimed[,
because] [t]he structural limitation does not manipulatively distinguish the
claimed subject matter from the prior art” (Ans. 5).
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Application 11/257,973

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Appellants’ arguments and the Examiner’s findings present us with
the following issue:
Does the combination of Lee and Hu teach or fairly suggest etching
away a first portion and second portion of a horizontal active region through
to the top surface of the substrate to leave a first horizontal active region and
a second horizontal active region?

PRINCIPLES OF LAW
Section 103(a) forbids issuance of a patent when ‘the differences
between the subject matter sought to be patented and the prior art are
such that the subject matter as a whole would have been obvious at
the time the invention was made to a person having ordinary skill in
the art to which said subject matter pertains.’

KSR Int'l Co. v. Teleflex, Inc., 550 U.S. 398, 406 (2007). The question of
obviousness is resolved on the basis of underlying factual determinations
including (1) the scope and content of the prior art, (2) any differences
between the claimed subject matter and the prior art, (3) the level of skill in
the art, and (4) where in evidence, so-called secondary considerations.
Graham v. John Deere Co., 383 U.S. 1, 17-18 (1966). See also KSR, 550
U.S. at 407, (“While the sequence of these questions might be reordered in
any particular case, the [Graham] factors continue to define the inquiry that
controls.”)
ANALYSIS
We are persuaded by Appellants’ argument that neither Lee nor Hu
discloses a process that results in a horizontal active region (App. Br. 11).
First, we agree with Appellants that horizontal step 112 of Lee does
not correspond to the claimed horizontal region, because it is masked during
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the implanting steps (Id.). Lee also contains several Figures illustrating
channel region 118 (e.g., Fig. 2G, Fig. 3D). We agree with Appellants that,
contrary to the Examiner’s finding (Ans. 9), horizontal step 112 is not within
channel region 118 (App. Br. 11).
Second, we do not agree with the Examiner that horizontal
semiconductor region 100 of Lee (e.g., Figure 2D, at bottom left and bottom
right) corresponds to first and second horizontal active regions (Ans. 4). Lee
discloses that substrate 100 is composed of a semiconductor such as silicon
(¶ [0035]). Because this region is disclosed as a substrate, and is not
disposed on an insulator as in Hu, we find that element 100 does not form a
horizontal active region as claimed.
Third, the Examiner does not point to any portion of Hu as disclosing
the claimed horizontal active regions.
Last, we find that the “horizontal active region” limitations at issue do
affect the method in a manipulative sense, are not the mere claiming of the
use of a particular structure, and thus are entitled to patentable weight. The
claims subsequently recite forming a gate dielectric over the first and second
horizontal active regions, and forming a source region and a drain region in
portions of the first and second horizontal active regions. The Examiner may
not disregard the claim term in formulating a rejection (see Ans. 5).
We find that neither Lee nor Hu teaches “etching away the first
portion and the second portion of the horizontal active region through to the
top surface of the substrate to leave the first horizontal active region and the
second horizontal active region.” We, therefore, conclude that the Examiner
erred in establishing the prima facie obviousness of claims 1-11. We will not
sustain the § 103 rejection.
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CONCLUSION
The combination of Lee and Hu does not teach or fairly suggest
etching away the first portion and the second portion of the horizontal active
region through to the top surface of the substrate to leave the first horizontal
active region and the second horizontal active region.

DECISION
The Examiner’s decision rejecting claims 1-11 is reversed.

REVERSED

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