Ex Parte Luk et al

Patent Trial and Appeal Board

Jun 28, 2013

11408752 (P.T.A.B. Jun. 28, 2013)

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.
11/408,752 04/21/2006 Wing K. Luk YOR920050629US1 1943
48063 7590 07/01/2013
RYAN, MASON & LEWIS, LLP
90 FOREST AVENUE
LOCUST VALLEY, NY 11560
EXAMINER
LIN, JOHN
ART UNIT PAPER NUMBER
2815
MAIL DATE DELIVERY MODE
07/01/2013 PAPER
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.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________

Ex parte WING K. LUK and JIN CAI
____________

Appeal 2010-012339
Application 11/408,752
Technology Center 2800
____________

Before CARL W. WHITEHEAD, JR., ERIC S. FRAHM, and
ANDREW J. DILLON, Administrative Patent Judges.

WHITEHEAD, JR., Administrative Patent Judge.

DECISION ON APPEAL
Appeal 2010-012339
Application 11/408,752

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STATEMENT OF THE CASE
Appellants are appealing claims 1, 4-14, 17, 18, 20-24, 36, and 37.
Appeal Brief 1. We have jurisdiction under 35 U.S.C. § 6(b) (2012).
We affirm.

Introduction
The invention is directed to a dynamic random access memory cell.
Appeal Brief 2-3.

Illustrative Claims (Emphasis Added)
1. A dynamic random access memory cell, comprising:
a capacitive storage device;
a write access transistor, said write access transistor
being operatively coupled to said capacitive storage device and
having a write access transistor gate stack, said write access
transistor gate stack comprising a write access transistor gate
stack high-K dielectric, wherein said write access transistor gate
stack high-K dielectric has a dielectric constant greater than a
dielectric constant of silicon dioxide, and wherein said write
access transistor gate stack further comprises a metal gate
electrode coupled to said write access transistor gate stack
high-K dielectric, and wherein said metal gate electrode
substantially exhibits a ¼ gap work function; and
a read transistor, said read transistor being operatively
coupled to said capacitive storage device and having a read
transistor gate stack, said read transistor gate stack comprising a
read transistor gate stack high-K dielectric, wherein said read
transistor gate stack high-K dielectric has a dielectric constant
greater than said dielectric constant of silicon dioxide.

4. The dynamic random access memory cell of claim 1,
wherein said read transistor gate stack further comprises a metal
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gate electrode coupled to said read transistor gate stack high-K
dielectric, and said metal gate electrode of said read transistor
substantially exhibits a band edge work function.

Rejections on Appeal
Claims 4, 7-9, 11, and 21-24 stand rejected under 35 U.S.C. § 112,
second paragraph, as being indefinite for failing to particularly point out and
distinctly claim the subject matter which Appellants regard as their
invention. Answer 4.
Claims 1 and 4-13 stand rejected under 35 U.S.C. §103(a) as being
unpatentable over Bhattacharyya (U.S. Patent Application Publication
Number 2003/0089942 A1; published May 15, 2003), Miyazaki (U.S. Patent
Number 5,103,423; issued April 7, 1992), and Smith Jr. (U.S. Patent
Number 3,811,076; issued May 14, 1974). Answer 4-9.
Claim 14 stands rejected under 35 U.S.C. §103(a) as being
unpatentable over Bhattacharyya, Miyazaki, Smith Jr., and Forbes (U.S.
Patent Number 6,104,045; issued August 15, 2000). Answer 10.
Claim 36 stands rejected under 35 U.S.C. §103(a) as being
unpatentable over Bhattacharyya, Miyazaki, Smith Jr., and Nelson (U.S.
Patent Number 3,876,991; issued April 8, 1975). Answer 10-11.
Claims 17, 18, and 20-24 stand rejected under 35 U.S.C. §103(a) as
being unpatentable over Bhattacharyya, Miyazaki, Smith Jr., and Noble
(U.S. Patent Number 6,066,869; issued May 23, 2000). Answer 11-15.
Claim 37 stands rejected under 35 U.S.C. §103(a) as being
unpatentable over Bhattacharyya, Miyazaki, Smith Jr., and Noble. Answer
15-16.

Appeal 2010-012339
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Issues on Appeal
Are dependent claims 4, 7-9, 11, and 21-24 indefinite because the
limitations “¼ gap work function” in claim 1 and “band edge work function”
in the dependent claims unclear?
Do Bhattacharyya, Miyazaki, Smith Jr., Forbes, Nelson, and Noble,
either alone or in combination, disclose “wherein said write access transistor
gate stack further comprises a metal gate electrode coupled to said write
access transistor gate stack high-K dielectric, and wherein said metal gate
electrode substantially exhibits a ¼ gap work function” as recited in claim 1
and independent claim 17?

ANALYSIS
35 U.S.C. §112 Rejection
Appellants argue that “contrary to the Examiner’s assertion, the term
‘band edge work function’ is not inclusive of the phrase ‘substantially
exhibits a ¼ gap work function.’” Appeal Brief 7. Appellants argue that
“the ‘band-gap’ is the difference between the conduction band edge and
valence band edge . . . .” Id. However, Appellants’ arguments are not
commensurate with the scope of the claims because the claims recite “¼ gap
work function” limitation in claim 1 and a “band edge work function”
limitation in claim 4 and not a “band gap.” Appellants have not persuaded
us that the terms are not related or inclusive as the Examiner finds. In claim
4, the limitation “a band edge work function” does not have an antecedent
basis to claim 1. Subsequently, claim 4 appears to be relatively broad and
hence is subject to a broad reasonable interpretation. However, we reverse
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the Examiner’s indefiniteness rejection because claim 4, while broad,
distinctly points out the Appellants’ invention.

35 U.S.C. §103 Rejection
Appellants contend that:
Independent claim 1 was rejected under 35 U.S.C.
§103(a) as allegedly being unpatentable over a proposed
combination of Bhat[tacharyya] in view of Miyazaki in
view of Smith [Jr.], and independent claim 17 was rejected
under 35 U.S.C. § 103(a) as allegedly being unpatentable
over a proposed combination of Bhat[tacharyya] in view
of Noble, in view of Miyazaki, in view of Smith [Jr.]. In
particular, the Examiner asserts that Bhat[tacharyya]
discloses said write access transistor gate stack comprising
a write access transistor gate stack high-K dielectric (104).
In the Response to Arguments section, the Examiner notes
that [A]pplicant[] provide alternative methods in which
aluminum can be used with high-K dielectrics without
using a high temperature anneal and asserts that a person
of ordinary skill in the art would have been motivated to
use aluminum in place of polysilicon for a gate electrode,
for example, because aluminum has a higher conductivity
than polysilicon. The Examiner asserts that it would
therefore have been obvious to modify Bhat[tacharyya] to
have made the gate from aluminum.
Appeal Brief 9.
Appellants provided a Declaration under 37 C.F.R §1.132 indicating
that the Examiner’s rejection of independent claims 1 and 17 is deficient
because the use of aluminum as a gate electrode is not warranted because
“aluminum is not thermally stable when the silicon wafer is treated with a
high temperature anneal necessary for electrical activation of implanted
dopant atoms such as boron.” Appeal Brief 9; see Answer 4-7. Appellants
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further contend that the technology disclosed by Smith Jr. is outdated and
“the industry no longer considers aluminum suitable for gate electrodes
because of its tendency to diffuse through dielectric and contaminate a
silicon transistor and has not considered utilizing aluminum for a gate
electrode for a high-K dielectric transistor.” Appeal Brief 10.
The Examiner finds:
Examiner notes that claims 1 and 17 are device claims and
not method claims. The patentability of a device does not
depend on its method of production. Further, the
[A]ppellant[s] admits that other methods can be used to
make the device so that aluminum can be used in the
device (the Declaration, paragraph 12; appeal brief page 9,
line 28-page 10, line 3). Even though a method exists for
making a transistor with an aluminum gate electrode, the
method in which a device is made in a device claims does
not have patentable weight. Therefore aluminum is a
suitable material for a gate electrode.
Answer 18-19.
We have considered Appellants’ arguments as well as the Declaration,
however, we do not find Appellants’ arguments to be persuasive nor are we
persuaded by the submitted Declaration. We considered Appellants’
Declaration to be informative but we did not find it persuasive because we
did not find it to be commensurate with the scope of the
claims.Consequently, we agree with the Examiner’s findings. Both claims 1
and 17 are broad in scope and are subject to a reasonable broad
interpretation. During examination of a patent application, a claim is given
its broadest reasonable construction “in light of the specification as it would
be interpreted by one of ordinary skill in the art.” In re Am. Acad. of Sci.
Tech Ctr., 367 F.3d 1359, 1364 (Fed. Cir. 2004) (citations omitted) (internal
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quotation marks omitted). “[T]he words of a claim ‘are generally given their
ordinary and customary meaning.’” Phillips v. AWH Corp., 415 F.3d 1303,
1312 (Fed. Cir. 2005) (en banc) (citations omitted).
Appellants’ argument that aluminum gate electrodes are outdated is
not persuasive because as the Examiner finds the claims do not preclude
means that would improve an aluminum gate electrode performance with
modern technological advancements. See Answer 19. Also, in spite of
aluminum’s structural limitations, Appellants have not provided evidence
that aluminum electrodes are no longer employed in the art. The submitted
Declaration addresses the alleged limitations of aluminum. Declaration;
paragraphs 9-12.
“[I]t is not necessary that the inventions of the references be
physically combinable to render obvious the invention under review.” In re
Sneed, 710 F.2d 1544, 1550 (Fed. Cir. 1983) (citing Orthopedic Equip. Co.
v. United States, 702 F.2d 1005, 1013 (Fed. Cir. 1983); In re Andersen, 391
F.2d 953, 958 (CCPA 1968)); see also In re Nievelt, 482 F.2d 965, 968
(CCPA 1973) (“Combining the teachings of references does not involve an
ability to combine their specific structures.”). “The test for obviousness is
not whether the features of a secondary reference may be bodily
incorporated into the structure of the primary reference . . . . Rather, the test
is what the combined teachings of the references would have suggested to
those of ordinary skill in the art.” In re Keller, 642 F.2d 413, 425 (CCPA
1981) (citations omitted).
The Examiner also finds that:
Examiner notes that the claims do not specify to
what material is being referenced for the ¼ gap work
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function, however, [A]pplicant[s’] specification discloses
that aluminum has a ¼ gap work function of silicon (page
8, lines 22-24). Bhat[tacharyya] discloses a write access
transistor gate stack (100) having a metal gate electrode
(108) coupled to a high-K dielectric (104) (Fig. 1) and
Smith [Jr.] discloses aluminum is a suitable material for a
gate electrode (column 3, lines 14-16). Bhat[tacharyya] in
view of Smith [Jr.] therefore discloses the write access
transistor gate stack further comprises a metal gate
electrode coupled to the write access transistor gate stack
high-K dielectric, and wherein the metal get electrode
substantially exhibits a ¼ gap work function. Examiner
further notes that since the claims do not specify to which
material is being referenced for the ¼ gap work function,
the metal gate electrode of the write access transistor of
Bhat[tacharyya] would inherently have a ¼ gap work
function of a material.
Answer 20.
Again, we agree with the Examiner’s findings and find that the
Examiners combination of references is proper and support his conclusion of
obviousness. The test for obviousness is what the combined teachings of the
references would have suggested to one of ordinary skill in the art. See In re
Kahn, 441 F.3d 977, 987-88 (Fed. Cir. 2006), In re Young, 927 F.2d 588,
591 (Fed. Cir. 1991), and In re Keller, 642 F.2d at 425. The Examiner can
satisfy this test by showing some articulated reasoning with some rational
underpinning to support the legal conclusion of obviousness.
Therefore, we sustain the Examiner’s obviousness rejection of
independent claims 1 and 17, as well as, dependent claims 4-14, 18, 20-24,
36, and 37 for reasons stated above.

DECISION
Appeal 2010-012339
Application 11/408,752

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The indefiniteness rejection of claims 4, 7-9, 11, and 21-24 is
reversed.
The obviousness rejections of claims 1, 4-14, 17, 18, 20-24, 36, and
37 are 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)(iv). See 37
C.F.R. § 41.50(f).

AFFIRMED

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