Ex Parte Liu et al

Patent Trial and Appeal Board

Jul 28, 2017

13486185 (P.T.A.B. Jul. 28, 2017)

United States Patent and Trademark Office
UNITED STATES DEPARTMENT OF COMMERCE
United States Patent and Trademark Office
Address: COMMISSIONER FOR PATENTS
P.O.Box 1450
Alexandria, Virginia 22313-1450
www.uspto.gov
APPLICATION NO. FILING DATE FIRST NAMED INVENTOR ATTORNEY DOCKET NO. CONFIRMATION NO.
13/486,185 06/01/2012 Chia-Chu Liu 2012-0096 / 24061.2129 5300
42717 7590 08/01/2017
HAYNES AND BOONE, LLP
IP Section
2323 Victory Avenue
Suite 700
Dallas, TX 75219
EXAMINER
SWAN, GARDNER W.S
ART UNIT PAPER NUMBER
2892
NOTIFICATION DATE DELIVERY MODE
08/01/2017 ELECTRONIC
Please find below and/or attached an Office communication concerning this application or proceeding.
The time period for reply, if any, is set in the attached communication.
Notice of the Office communication was sent electronically on above-indicated "Notification Date" to the
following e-mail address(es):
ipdocketing@haynesboone.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte CHIA-CHU LIU, SHIAO-CHIAN YEH,
HONG-JANG WU, and KUEI-SHUN CHEN
Appeal 2016-005013
Application 13/486,185
Technology Center 2800
Before MARKNAGUMO, JAMES C. HOUSEL, and
MERRELL C. CASHION, JR., Administrative Patent Judges.
Opinion for the Board by HOUSEL, Administrative Patent Judge.
Dissenting Opinion by NAGUMO, Administrative Patent Judge.
DECISION ON APPEAL1
1 Our decision refers to the Specification (Spec.) filed June 1, 2012, the
Examiner’s Final Office Action (Final Act.) dated January 16, 2015,
Appellants’ Appeal Brief (App. Br.) filed September 21, 2015, the
Examiner’s Answer (Ans.) dated February 10, 2016, and Appellants’ Reply
Brief (Reply Br.) filed April 8, 2016.
Appeal 2016-005013
Application 13/486,185
Pursuant to 35 U.S.C. § 134(a), Appellants2 appeal from the
Examiner’s decision rejecting claims 1—9, 11, 12, 14, and 21—25. We have
jurisdiction over the appeal under 35 U.S.C. § 6(b).
We AFFIRM.
STATEMENT OF THE CASE
The invention relates to a semiconductor device having at least one
non-orthogonal element, which Appellants define as any element that
includes an inclined or slanted feature, e.g., that is not at a substantially right
angle or perpendicular to a referenced feature. Spec. 1 8. Appellants further
disclose that the non-orthogonal element may be the end of a gate structure
that is formed by a non-orthogonal cut in the method of making the
semiconductor device. Id. For example, Appellants disclose that the cut
may extend across the gate structures of the device at an angle other than 90
degrees, such as approximately 45 degrees, with respect to a centerline
drawn along the length of the gate structures. Id. ^ 16.
Claim 1, reproduced below from the Claims Appendix to the Appeal
Brief, is illustrative of the subject matter on appeal. The limitation at issue
is italicized.
1. A semiconductor device, comprising:
a first gate structure segment and a collinear second gate
structure segment;
a third gate structure segment and a collinear fourth gate
structure segment;
wherein the first gate structure segment has an end with a
face defined by linear edges, wherein a plane extending from
the face is non-orthogonal to a sidewall of the first gate
2 According to Appellants, the real party in interest is Taiwan
Semiconductor Manufacturing Company, Ltd. App. Br. 3.
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Application 13/486,185
structure;
spacer elements formed on a first and second sidewall of
the first gate structure segment; and
an interconnection structure extending from the end of
the first gate structure segment to the fourth gate structure
segment, wherein the interconnection structure is disposed
above the first gate structure segment and the fourth gate
structure segment, and wherein the interconnect structure has a
planar bottom surface that extends from having an interface
directly on the first gate structure across to having an interface
directly on the fourth gate structure segment, and wherein the
planar bottom surface of the interconnection structure is
disposed directly on a top surface of the spacer elements on the
first and second sidewalls of the first gate structure segment.
Independent claim 7 similarly recites a semiconductor device
comprising, among other things, “a plane extending from a rectangular face
of an end of the second gate structure is not substantially perpendicular to
sidewalls of the second gate structure.”3 Remaining independent claim 21
also similarly recites a semiconductor device comprising, among other
things, “an end of the first gate structure has a face that is angled
approximately 45 degrees from a centerline along a length of the gate
structure.”
REJECTIONS
The Examiner maintains, and Appellants request our review of, the
following grounds of rejection under 35 U.S.C. § 103(a):
1. Claims 1—4, 6—9, 11, 12, 14, 21, 22, and 24 as unpatentable over
3 Claim 7 also recites that the first gate structure is non-orthogonally
disposed with respect to the second gate structure. However, because the
second gate structure is parallel to the first gate structure, these two gate
structures by definition are non-orthogonal to each other.
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Becker4 in view of Houston,5 6 7as evidenced by Ema;6,7 and
2. Claims 5, 23, and 25 as unpatentable over Becker, Houston, and
Ema, as applied to claim 1 above, and further in view of Ngo.8
ANALYSIS
Appellants do not argue the claims separately, instead focusing on the
substantively common limitation in each of independent claims 1,7, and 21.
In accordance with the provisions of 37 C.F.R. § 41.37(c)(l)(iv) (2015), we
select claim 1 to address Appellants’ arguments. The remaining claims
stand or fall with claim 1.
The dispositive issue before us on appeal is: Have Appellants
identified reversible error in the Examiner’s determination that the non-
orthogonal end face of a gate structure would have been an obvious matter
of design given the teachings of Becker and Ema?9 For the reasons given by
4 US 2009/0224317 Al, published September 10, 2009.
5 US 6,737,347 Bl, issued May 18, 2004.
6 US 5,148,246, issued September 15, 1992.
7 Ema was first cited by the Examiner in the Advisory Action of April 27,
2015, in response to a challenge to the Examiner’s Official Notice in the
Final Office Action, and is relied on in the Answer as evidence that gate
structures with non-orthogonal end faces were known in the art. Ans. 2—8.
Although the Examiner’s statement of rejection in the Final Office Action
fails to include Ema, the Examiner’s statement of rejection in the Answer
clearly indicates that Ema is relied on as an evidentiary teaching. Id. at 2.
Appellants object (App. Br. 15), but respond on the merits, so there is no
harmful error.
8 US 6,051,870, issued April 18, 2000.
9 The Examiner applies Houston for teaching various features of the claimed
invention which the Examiner acknowledges are not taught by Becker.
Final Act. 4. Appellants do not dispute the Examiner’s findings with regard
to Houston, nor argue against the Examiner’s combination of Becker and
Houston. As such, any further discussion of Houston is unnecessary.
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the Examiner in the Final Office Action and Answer as well as below, we
answer this question in the negative. We, therefore, sustain the Examiner’s
obviousness rejections based on the findings of face, conclusions of law, and
rebuttals to arguments well expressed by the Examiner which we adopt as
our own. The following comments are added for emphasis.
The Examiner finds, in pertinent part, that Becker, Figure 16C,
teaches a semiconductor device having first, second, third, and fourth gate
structures 401 A, 405A, 403A, 407A, wherein first and second gate
structures 401 A, 405A are aligned, parallel, and spaced apart from each
other, third and fourth gate structures 403A, 407A are aligned, parallel, and
spaced apart from each other, with interconnect 1621 disposed over and
connecting first and fourth gate structures 401A, 407A. Final Act. 2—3. The
Examiner acknowledges that the end faces of Becker’s gate structures are
not non-orthogonal to sidewalls thereof. Id. at 3. However, the Examiner
finds that it was known in the art that these end faces have a shape. Id. The
Examiner also finds the claimed shape, non-orthogonal end faces of the gate
structures, was known in the art as evidenced by Ema. Ans. 2—8; see also
the Advisory Action dated April 27, 2015. In addition, the Examiner finds
that “[pjersuasive evidence that the claimed shape of the gate structure is
significant has not been provided.” Final Act. 3.
Appellants argue that the combination of Becker and Houston fails to
teach the claimed shape, i.e., non-orthogonal, of the end face of the gate
structure and that such a shape is not an obvious design choice. App. Br. 9—
17. In particular, Appellants contend that the claimed shape provides the
benefit that the gate structures may be fabricated in a single
photolithography and etching process. Id. at 12 (citing Spec. 15—20). As
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such, Appellants urge that the Specification provides an advantage and
purpose for the claimed shape. Id. at 14. Appellants further assert that the
Examiner has not shown that the claimed shape was known in the art, or that
the claimed shape would have performed equally well as a known
alternative. Id. at 13, 14—15.
In addition, Appellants argue that Ema fails to provide evidence that
providing the claimed shape in Becker would have been obvious as a known
alternative end face shape. App. Br. 15. Appellants assert that Ema only
provides a different shape for the end face of a gate structure for a specific
type of gate in a specific arrangement, that of a control gate under a floating
gate where the shape at the end of a control gate is defined by the overlying
floating gate. App. Br. 15; see also Reply Br. 4—5. Appellants further assert
that Ema teaches the end faces of the control gate structure is defined by an
isolation structure and the overlying floating gate. App. Br. 15. Appellants
note that Becker does not describe a floating gate under a control gate. Id. at
16. Moreover, Appellants urge that making Becker’s end faces parallel to
the isolation regions would mean that Becker’s end faces would remain
orthogonal to the gate structure. Id.
We do not find Appellants’ arguments persuasive of reversible error.
As the Examiner notes, the advantage of the claimed shape urged by
Appellants is not directed to the claimed shape per se, but to how the
claimed shape may be made. However, as acknowledged by Appellants, the
claims are not directed to the method of making the semiconductor device,
nor are they directed to a product by process. Id. at 14. Appellants do not
provide any evidence that the semiconductor device comprising a gate
structure with the claimed shape of the end face performs any function or
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has any purpose different from Becker’s semiconductor device having
Becker’s disclosed gate structure with an orthogonal end face shape. See In
re Gal, 980 F.2d 717, 719 (Fed. Cir. 1992) (finding of “obvious design
choice” precluded where the claimed structure and the function it performs
are different from the prior art). Nor have Appellants provided any evidence
that the claimed shape produces an unexpected result. In re Rice, 341 F.2d
309, 314 (CCPA 1965) (“Appellants have failed to show that the change [in
the claimed invention] as compared to [the reference], result[s] in a
difference in function or give unexpected results.”).
In addition, as the Examiner finds (Ans. 4), other shapes, including
Becker’s, may be made in a single photolithography and etching process
using a correctly designed mask. Conversely, there is no requirement or
limitation in the claims that the claimed shape is formed in a single
photolithography and etching process—the claims are not product-by­
process claims. Indeed, the Specification merely teaches that the gate
structures may be sectioned non-orthogonally using a single
photolithography and/or etching process, not that the non-orthogonal cut
must be formed this way. Spec. 120. Accordingly, we discern no error in
the Examiner’s finding that “the claimed shape is not uniquely associated
with the alleged process advantage.” Ans. 4.
Turning to the Examiner’s evidence in support of the finding that the
claimed shape was a known alternative shape, the Examiner notes that Ema
was relied on merely to support the stated position and not for further
modifying Becker. Ans. 7. “It is well established that a determination of
obviousness based on teachings from multiple references does not require an
actual, physical substitution of elements.” In re Mouttet, 686 F.3d 1322,
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1332 (Fed. Cir. 2012) (citing In re Etter, 756 F.2d 852, 859 (Fed. Cir. 1985)
(en banc)); see also In re Keller, 642 F.2d 413, 425 (CCPA 1981) (“To
justify combining reference teachings in support of a rejection it is not
necessary that a device shown in one reference can be physically inserted
into the device shown in the other.”). “Rather, the test is what the combined
teachings of the references would have suggested to those of ordinary skill
in the art.” Keller, 642 F.2d at 425.
Ema teaches an embodiment wherein the gate structures have a
substantially parallelogram planar surface shape such that the short ends
(end faces) of the gate structures 15 run parallel to the long-side edges of the
isolation regions 2. Ema 6:23—28. However, Appellants do not direct our
attention to any teaching in Ema that provides that the end faces of the gate
structures 15 at any particular angle relative to the isolation regions has any
purpose or performs any function, nor do we find any. Ema merely requires
that the area of each gate structure 15 overlying regions 3 (which is
unrelated to the end face shape of the gate structure 15) does not change due
to positional error. Id. at 6:29-35. Indeed, Ema is silent, as is the entire
record in this case, that the end face shape of the gate structure has any
effect on function or performance. Thus, Ema evidences that the shape of
the end face of the gate structures is neither critical nor has any function
other than as a feature of design choice.
Accordingly, we are persuaded that the ordinary artisan would have
recognized that the shape of the end faces of the gate structures in Becker
may be altered as an obvious design choice to provide the claimed shape.
Cf. Kuhle, 526 F.2d 553, 555 (CCPA 1975) (finding that the use of the
claimed feature “would be an obvious matter of design choice” when it
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“solves no stated problem” and “presents no novel or unexpected result”
over the disclosed alternatives). In this context, a non-orthogonal end face
of the gate structure has the same functionality and purpose as an orthogonal
end face, and “cannot be used as a distinguishing factor to render the claims
nonobvious.” In re Magna Electronics, Inc., 611 F. App’x 969, 974 (Fed.
Cir. 2015).
In reaching this conclusion, we are mindful of the guidance provided
in Ex parte Gunasekar, 2011 WL 3872007, at *5 (BPAI Aug. 29, 2011):
When determining whether a rejection based on design
choice is appropriate, the Examiner must review the
Specification and ascertain if the limitation in question is
disclosed as serving any advantage or particular purpose, or
whether it solves a stated problem. The Examiner also should
explain the reasoning used to determine that the prior art would
have performed equally as well as the claimed invention. These
two steps help present the aforementioned “convincing line of
reasoning.” Ex parte Clapp, 227 USPQ [972,] 973 [(BPAI
1985)].
Here, the Examiner and we have reviewed the record, including the
Specification, to ascertain if the limitation in question is disclosed as serving
any advantage or particular purpose, or whether it solves a stated problem.
Like the Examiner, we find no evidence that the claimed shape of the end
faces of the gate structures serve any advantage or particular purpose or
solve any stated problem. Moreover, as the gate structure is otherwise
unaltered, there is no reason in this record that the ordinary artisan would
expect any performance difference between semiconductor devices having
orthogonal and non-orthogonal end faces.
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Accordingly, we are not persuaded that the Examiner reversibly erred
in rejecting claim 1 over the proposed combination of Becker and Houston,
as evidenced by Ema.
DECISION
Upon consideration of the record, and for the reasons given above and
in the Final Office Action and the Answer, the decision of the Examiner
rejecting claims 1—9, 11, 12, 14, and 21—25 under 35 U.S.C. § 103(a) as
unpatentable over Becker in view of Houston and Ema, alone or further in
view of Ngo, is affirmed.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a)(1).
AFFIRMED
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NAGUMO, Administrative Patent Judge, dissenting.
I dissent, with respect.
The key limitation for purposes of resolving this appeal is the
requirement that there be a “gate structure segment having an end with a
face defined by linear edges, wherein a plane extending from the face is non-
orthogonal to a sidewall of the first gate structure.” (App. Br. 19, claim 1.)
Becker describes a cross-coupled transistor configuration.s as a
distinct alternative to cross-coupled inverters used for Static Random Access
Memory (SRAM) bit cell circuits. (Becker, [0053]—[0062].) Figure 16C,
shown on the following page with added annotations, illustrates the features
relevant in this appeal. Gate 401A of a first transistor is connected via
conductive traces, including link 1621, to gate 407A of a fourth transistor.
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{Becker Figure 16C is shown below}
{Becker Fig. 16 shows a cross-coupled transistor circuit}
As the Examiner recognized in the Final Rejection, gate 401A does
not have a face non-orthogonal to its sidewalls. The Examiner took official
notice that various shaped faces were known in such circumstances, and,
when challenged, cited Ema as evidence supporting the notice. (Advisory
Action entered 24 April 2015).
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Ema teaches, in Figure 9, shown below,
}7
{Figure 9 shows floating electrodes 15 in a nonvolatile memory device}
a nonvolatile semiconductor memory device that comprises floating gate 15,
which is a parallelogram. Assuming floating gate 15 has a face and
sidewalls, the face is non-orthogonal to the sidewalls.10
The difficulty with this analysis, as Appellants point out (App. Br. 15—
16), is that floating electrode 15 not the same as any structure in Becker. In
my view, the Examiner has not explained why the floating gate of Ema
corresponds sufficiently to gate 401A or to any other structure of Becker,
that the routineer would have considered using a non-orthogonal face on any
gate in Becker.
Accordingly, I would reverse the appealed rejections, and I dissent,
respectfully, from the Decision to Affirm.
10 Ema explains that if a charge is stored on floating gate 15, the circuit can
recognize that no information is stored in selected EPROM cell T; but if no
charge is stored on floating gate 15, the circuit can recognize that
information has been stored in that EPROM cell. (Ema, col. 5,11. 1—15.)
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