Ex Parte Inoue et al

Patent Trial and Appeal Board

Oct 11, 2012

10901124 (P.T.A.B. Oct. 11, 2012)

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.
10/901,124 07/29/2004 Ken Inoue NEC00P267-hk div 8661
21254 7590 10/12/2012
MCGINN INTELLECTUAL PROPERTY LAW GROUP, PLLC
8321 OLD COURTHOUSE ROAD
SUITE 200
VIENNA, VA 22182-3817
EXAMINER
MATTHEWS, COLLEEN ANN
ART UNIT PAPER NUMBER
2811
MAIL DATE DELIVERY MODE
10/12/2012 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 KEN INOUE and MASAYUKI HAMADA
____________

Appeal 2010-004986
Application 10/901,124
Technology Center 2800
____________

Before DENISE M. POTHIER, BRUCE R. WINSOR, and
BARBARA A. BENOIT, Administrative Patent Judges.

BENOIT, Administrative Patent Judge.

DECISION ON APPEAL

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Application 10/901,124

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STATEMENT OF THE CASE
Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1, 3, 4, 10, 20-23, 25-33, and 35-43. Claims 2, 5-9,
11-19, 24, and 34 have been cancelled. App. Br. 2. We have jurisdiction
under 35 U.S.C. § 6(b). We affirm.

Invention
Appellants’ invention relates to a semiconductor device which has a
DRAM section and a logic section formed on the same substrate. See
generally Abstract; Spec. 1. Claim 1 is illustrative and reads as follows,
with key disputed limitations emphasized:
1. A DRAM-incorporated semiconductor device comprising:
a DRAM section;
a logic section formed on the same substrate as said DRAM section;
plural transistors formed in said DRAM and logic sections, said
transistors comprising source-drain regions including a lightly-doped region
and a highly-doped region having a higher impurity density than said lightly-
doped region; and
a silicide layer which comprises one of cobalt silicide and nickel
silicide and is formed, at least, on substantially an entire surface of said
highly-doped region of said source-drain regions of said transistors in the
DRAM section and the logic section, such that an interface between said
silicide layer and said highly-doped region is located under a main surface
of said substrate,
wherein a P-N junction between said highly-doped region and a well
in said substrate is deeper than a P-N junction between said lightly-doped
region and said well.
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The Examiner relies on the following as evidence of unpatentability:
Mitani US 5,864,161 Jan. 26, 1999
Seo US 5,981,324 Nov. 9, 1999
Lin US 6,107,154 Aug. 22, 2000
Noble US 2002/014660 A1 Feb. 7, 2002
(filed Feb. 27, 1998)

The Rejections
1. The Examiner rejected claims 1, 3, 10, 20, 22, 23, 25-27, 29, 30,
32, 33, 35, 37-41, and 43 under 35 U.S.C. § 103(a) as unpatentable over Seo
and Lin. Ans. 3-7.1
2. The Examiner rejected claims 4, 28, and 36 under 35 U.S.C.
§ 103(a) as unpatentable over Seo, Lin, and Mitani. Ans. 7-8.
3. The Examiner rejected claims 21, 31, and 42 under 35 U.S.C.
§ 103(a) as unpatentable over Seo, Lin, and Noble. Ans. 8-10.

THE OBVIOUSNESS REJECTION OVER SEO AND LIN
The Examiner finds that Seo discloses every recited feature of
illustrative claim 1 except for a silicide layer which comprises one of cobalt
silicide and nickel silicide. Ans. 3-4. For this feature, the Examiner cites
Lin in concluding that the claim would have been obvious. Ans. 4 (citing
Lin, col. 7, ll. 7-11).
Appellants argue that the Examiner has failed to show that Seo, Lin,
or any combination of the references teaches or suggests “a silicide layer

1 Throughout this opinion, we refer to 1) the Appeal Brief filed May 1, 2009;
2) the Examiner’s Answer mailed October 5, 2009; and 3) the Reply Brief
filed December 7, 2009.
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which comprises one of cobalt silicide and nickel silicide and is formed, at
least, on substantially an entire surface of said highly-doped region of said
source-drain regions of said transistors in the DRAM section and the logic
section, such that an interface between said silicide layer and said highly-
doped region is located under a main surface of said substrate,” as recited in
claim 1 (emphases added). App Br. 20; see also id. at 16-18, 25; Reply Br.
1. Appellants also argue that Lin teaches away from the combination. App.
Br. 18-25; Reply Br. 1-4.

Issues
1. Under § 103, has the Examiner erred in rejecting the claims by
finding that Seo and Lin collectively teach or suggest the recited silicide
layer?
2. Under § 103, is the Examiner’s reason to combine the teachings of
Seo and Lin supported by articulated reasoning with some rational
underpinning to justify the Examiner’s obviousness conclusion? More
particularly, this issue turns on whether Lin teaches away from the
combination.

Analysis
INDEPENDENT CLAIM 1
We are not persuaded of error in the Examiner’s rejection based on
Seo and Lin. Regarding illustrative claim 1, Appellants argue that the
Examiner has failed to show that Seo, Lin, or any combination of the
references teaches or suggests a silicide layer which comprises one of cobalt
silicide and nickel silicide and is formed, at least, on substantially an entire
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surface of said highly-doped region of said source-drain regions of said
transistors in the DRAM section and the logic section, such that an interface
between said silicide layer and said highly-doped region is located under a
main surface of said substrate, as recited by claim 1. App. Br. 20; see also
id. at 16-18, 25; Reply Br. 1.
Specifically, Appellants challenge the Examiner’s finding (Ans. 4)
that Lin teaches a silicide layer including one of cobalt silicide and nickel
silicide. App. Br. 16-18, 20; Reply Br. 1-3. The Examiner’s finding is
based on Lin’s disclosure that the “metal layer 342 is formed from a
refractory metal such as . . . cobalt, nickel,” among others. Lin, col. 7,
ll. 8-11; Ans. 4. Appellants acknowledge that Lin teaches “a metal layer 342
formed over the silicon layer 336, 338 . . . . [and] that an annealing process
is then performed to convert the silicon layers 336, 338 to titanium silicide
and form the titanium silicide layers 348, 350.” Reply Br. 2 (citing Lin, col.
7, ll. 4-7; Figs. 3D, 3E) (emphasis omitted); see also App. Br. 19 (citing Lin,
col. 7, ll. 1-37). Although Lin discusses titanium (rather than cobalt or
nickel) as the preferred refractory metal used to form the metal layer 342
(col. 7, ll. 10-12), Lin’s teaching is unambiguous that the metal layer, which
is converted to silicide layers (col. 7, ll. 21-26), may be formed from cobalt
or nickel as an alternative to titanium (col. 7, ll. 7-10). Accordingly, we are
not persuaded that the Examiner erred in finding that Lin teaches a silicide
layer including one of cobalt silicide and nickel silicide.
Appellants also assert that Lin does not teach that the silicide layer is
formed on a highly-doped region of the source-drain regions in the DRAM
section such that an interface between the silicide layer and the highly-doped
region is located under a main surface of the substrate. Reply Br. 2-3; see
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also App. Br. 17, 19-20. Appellants’ argument is unavailing because the
argument is not consistent with the Examiner’s proposed rejection. The
Examiner relies on Lin merely for the “general teaching to substitute well
known cobalt or nickel silicide materials for the silicide materials taught in
Seo.” Ans. 11-12; see also Ans. 3-4. The Examiner relies on Seo for all of
the other features recited by claim 1, including relying on Seo for teaching a
device where the silicide layer is a refractory metal silicide formed directly
on surfaces of highly doped source-drain regions in the DRAM and logic
sections. Ans. 11 (citing Seo, col. 3, ll. 64-66); see also Ans. 3-4.
Appellants also assert that there is no motivation or suggestion to
combine the references. App. Br. 21; Reply Br. 4. We disagree and note
that the Examiner concluded that
[i]t would have been obvious to one have ordinary skill in the
art to incorporate the teaching of Lin into the device taught by
Seo . . . since cobalt and nickel silicides are know[n] materials
that are well suited for the intended use to achieve desired
device characteristics such as low resistance
(Ans. 4) and “to provide optimum resistivity of the device contact point”
(Ans. 15). Thus, the Examiner’s proposed combination of Seo and Lin
predictably uses prior art elements according to their established functions—
an obvious improvement. See KSR Int’l Co. v. Teleflex Inc., 550 U.S. 398,
417 (2007).
Additionally, we turn to whether Lin teaches away from combining
the cobalt silicide and nickel silicide disclosed in Lin with the integrated
circuit taught by Seo, as Appellants assert. See App. Br. 20. The question
before us is whether a person of ordinary skill, upon reading Lin’s
disclosure, would be discouraged from using a silicide layer of cobalt
silicide or nickel silicide, as disclosed in Lin, in the portion of an integrated
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circuit shown in Seo’s Figure 3. See In re Kahn, 441 F.3d 977, 990 (Fed.
Cir. 2006) (stating “[a] reference may be said to teach away when a person
of ordinary skill, upon reading the reference, would be discouraged from
following the path set out in the reference, or would be led in a direction
divergent from the path that was taken by the applicant”).
The Examiner uses Lin for the limited purpose of disclosing a silicide
layer made from one of cobalt silicide or nickel silicide and relies on Seo for
all of the other limitations of claim 1. Ans. 3-4. As discussed above, and
recognized by Appellants (App. Br. 19; Reply Br. 2), Lin discloses forming
a titanium silicide layer from a refractory metal layer made of titanium and
also discloses that other refractory metals (including cobalt and nickel) can
be used in the refractory metal layer. See Lin, col. 7, ll. 7-24. Thus, Lin
teaches or suggests that cobalt silicide or nickel silicide can be used in place
of Lin’s titanium silicide layer.
Moreover, contrary to Appellants’ argument that Lin teaches away
because of Lin’s disclosure of a preferred embodiment and preference for
titanium (App. Br. 22; Reply Br. 4), this disclosure does not rise to the level
of a teaching away because, while Lin does indicate titanium is preferred,
Lin does not discourage the use of a layer of cobalt silicide or nickel silicide
(col. 7, ll. 7-11, 45-51). See DePuy Spine, Inc. v. Medtronic Sofamor Danek,
Inc., 567 F.3d 1314, 1326-27 (Fed. Cir. 2009) (stating “[a] reference does
not teach away, however, if it merely expresses a general preference for an
alternative invention but does not criticize, discredit, or otherwise discourage
investigation into the invention claimed”) (citation and internal quotation
marks omitted). Notably, the portion of Seo relied on by the Examiner for
the recited silicide layer discloses a titanium silicide layer, which is the same
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type of material in Lin’s preferred embodiment. Compare Lin, col. 7, ll. 21-
25 with Seo, col. 3, ll. 40-42 (referring to Fig. 3).
Appellants also argue that Lin teaches away from the use of the cobalt
silicide or nickel silicide in Seo’s device because the use of those materials
could cause further thinning of the shallow P-N junction, as titanium silicide
does, and because of other difficulties of Lin’s techniques. App. Br. 19-22;
Reply Br. 4. Even assuming that using cobalt silicide or nickel silicide in
Seo’s device results in the thinning of the material as asserted by Appellants,
some material remains, and thus Lin does not discouraged using a cobalt or
nickel silicide layer in Seo’s device.
Nor does the identification of Seo’s Figure 3 as prior art to Lin’s
disclosure teach away from substituting Lin’s cobalt silicide or nickel
silicide for Seo’s titanium silicide layer, as Appellants assert (App. Br. 21-
23; Reply Br. 4). Accord In re Mouttet, 686 F.3d 1322, 1333-34 (Fed. Cir.
2012) (stating that the existence of better alternatives “in prior art does not
mean that an inferior combination is inapt for obviousness purposes” (citing
In re Gurley, 27 F.3d 551, 553 (Fed. Cir. 1994))). Taken as a whole, then,
the mere substitution of cobalt silicide or nickel silicide for titanium silicide
is not discouraged by the alleged difficulties of using Lin’s techniques
discussed by Appellants, which were not relied on by the Examiner. See
Kahn, 441 F.3d at 990.
Appellants also argue that the references cannot be bodily combined.
App. Br. 19 (noting that Seo’s silicide layer is located under the main
surface of the substrate, whereas Lin’s silicide layer is over the main surface
of the substrate); see also id. at 21, 25; Reply Br. 3. Moreover, Appellants
assert that a skilled artisan would not combine Lin and Seo because of Seo’s
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disclosure of crystalline defects (App. Br. 22) and that Lin lacks a disclosure
of the advantage of cobalt silicide or nickel silicide in reducing crystalline
defects compared with titanium silicide (Reply Br. 4). These arguments are
unavailing. First, bodily incorporation is not necessary in an obviousness
rejection. See In re Keller, 642 F.2d 413, 425 (CCPA 1981). Second, even
if better alternatives exist in the prior art, that does not mean that an inferior
combination is inapt for obviousness purposes. See Mouttet, 686 F.3d at
1333-34. Third, as noted above, the Examiner has relied upon Lin to teach
cobalt and nickel silicide layers were known substitutes for a titanium
silicide layer and not for the location of the interface. See Ans. 3-4.
Appellants assert that the inventors have discovered an unexpected
and remarkable effect that use of cobalt silicide or nickel silicide in the
recited silicide layer reduces current leakage as compared with Seo’s usage
of a titanium silicide layer. App. Br. 23-24. Appellants further refer to their
After-Final Amendment filed July 10, 2007, which (as resubmitted on July
13, 2007) included a graph showing the beneficial effect of cobalt silicide
and nickel silicide over titanium silicide. In response, the Examiner
maintained the rejection as stated in the Advisory Action mailed July 23,
2007. Notably, Appellants have not submitted any evidence concerning the
graph in their appeal. See App. Br. 49 (stating, in the Evidence Appendix of
the Appeal Brief, “Not Applicable”); see also 37 C.F.R. § 41.37(c)(1)(ix)
(requiring copies of submitted evidence in the Evidence Appendix and a
statement setting forth where in the record that evidence was entered). As
such, we will not consider any purported evidence that is not properly before
us.
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We also note, as does the Examiner (Ans. 15-16), the distinction
between a prior art reference and a technique being abandoned. Appellants
have not presented sufficient evidence that Seo’s technique has been
abandoned. See App. Br. 23.
Therefore, we find the Examiner’s reason to combine the teachings of
the cited references supported by articulated reasoning with some rational
underpinning to justify the Examiner’s obviousness conclusion. We are not
persuaded of Examiner error, and, accordingly, we sustain the Examiner’s
rejection of claim 1.

INDEPENDENT CLAIMS 10 AND 33
We likewise are not persuaded of error in the Examiner’s obviousness
rejection of independent claims 10 and 33, which each recite a silicide layer
limitation similar to the silicide layer recited by claim 1. For the rejection of
independent claims 10 and 33, Appellants refer to the previous arguments of
claim 1. App. Br. 25-27, 29-30; Reply Br. 7. For the same reasons
discussed above with respect to claim 1, we are not persuaded of Examiner
error in the rejections of claims 10 and 33.

DEPENDENT CLAIMS 3, 20, 22, 23, 25-27, 29, 30, 32, 35, 37-41, AND 43
Regarding claim 3, which depends from claim 1, Appellants challenge
the Examiner’s finding (Ans. 4, 17) that Seo teaches the additional feature
recited by claim 3. Appellants assert that the Examiner’s position is flawed
because Seo does not teach or suggest, in the cited passage or elsewhere, the
feature recited by claim 3. App. Br. 31. Merely pointing out what a claim
recites and then asserting that the reference fails to teach the recited feature
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is not considered a separate argument for patentability. See In re Lovin, 652
F.3d 1349, 1357 (Fed. Cir. 2011). Even so, we note the Examiner finds Seo
teaches such a limitation and Appellants have not adequately rebutted this
finding.
Similarly, Appellants challenge the Examiner’s findings that Seo, in
various specified passages, teaches the features recited by claim 20 (Ans. 4),
claim 22 (id. at 5, 18), claim 23 (id. at 5, 19), claim 25 (id.), claim 26 (id.),
claim 27 (id. at 5, 20), claim 29 (id. at 5, 20-21 ), claim 30 (id. at 6, 21),
claim 32 (id. at 6, 22), claim 35 (id. at 4, 22), claim 37 (id. at 6, 23), claim
38 (id. at 6, 24), claim 392 (id.), claim 40 (id. at 6-7, 24-25), claim 41 (id. at
6-7, 25), and claim 43 (id. at 6-7, 26). As with claim 3, Appellants assert the
Examiner’s position is flawed merely by asserting that Seo does not teach
the feature recited respectively in each of claims 20, 22, 23, 25-27, 29, 30,
32, 35, 37-41, and 43. See App. Br. 32-41.
For the same reasons discussed above with respect to claim 3, we are
not persuaded of Examiner error in the rejection of claims 20, 22, 23, 25-27,
29, 30, 32, 35, 37-41, and 43.

2 Appellants correctly note that the Examiner did not assert the particular
passage in Seo where the feature recited by claim 39 is found. Compare
App. Br. 38-39 with Ans. 6. The Examiner did, however, in the Response to
Arguments section, particularly point out where Seo taught feature recited
by claim 39. Ans. 24. Appellants did not address this finding related to
claim 39 in Appellants’ Reply Brief. See generally Reply Br. 1-7. We find
any error associated with this inconsistency harmless on this record.
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THE OBVIOUSNESS REJECTION OVER SEO, LIN, AND MITANI
DEPENDENT CLAIMS 4, 28, AND 36
In rejecting claim 4, which depends from claim 1, the Examiner cited
various portions of Seo, Lin, and Mitani for the additional features recited by
dependent claim 4. Ans. 7, 17-18. Appellants only challenge the
Examiner’s finding with respect to Mitani. App. Br. 31-32. Moreover,
Appellants assert that the Examiner’s position is flawed by asserting merely
that Mitani does not teach the additional features recited by claim 4. For
reasons similar to those discussed above with respect to claim 3 related to
merely pointing out what a claim recites and then asserting that the reference
fails to teach the recited feature, we are not persuaded of Examiner error in
the rejection of claim 4.
Appellants also summarily assert that the Examiner erred in finding
that the additional feature recited by: (1) claim 28 is taught by Seo (Ans. 7-8,
20) and (2) claim 36 is taught by Seo, Lin, and Mitani (Ans. 7, 22-23). App.
Br. 34-35, 37. We are not persuaded for the same reasons discussed above
with respect to claim 3.

THE OBVIOUSNESS REJECTION OVER SEO, LIN, AND NOBLE
CLAIMS 21, 31, AND 42
Independent claim 21 recites a DRAM section including a memory
cell, a decoder, and sense amplifier, among other limitations. Independent
claim 21 also recites a silicide layer which comprises one of cobalt silicide
and nickel silicide and is formed on substantially an entire surface of said
second impurity diffused region in said DRAM and the logic sections, such
that an interface between said silicide layer and said source-drain region is
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located under a main surface of said substrate. The Examiner relies on Seo
and Lin for teaching the silicide layer. Ans. 8-9. For teaching the DRAM
that includes a decoder and sense amplifier, the Examiner relies on Noble.
Ans. 9 (citing Noble, ¶ 0037; Fig. 6). This is a finding that Appellants do
not challenge. See App. Br. 28 (stating “Noble teaches a DRAM circuit 40
that includes ‘a number of subcircuits’ such as decoders 44, 45 and amplifier
circuit 48” (citing Noble, ¶ 0037)).
Appellants challenge the Examiner’s finding and obviousness
conclusion relying on the same arguments made with respect to claim 1.
App. Br. 27-28. Appellants also assert that Noble does not disclose the
silicide layer and therefore does not cure the alleged deficiency of Seo and
Lin. App. Br. 28. We refer to our previous discussion and need not address
whether Noble cures any alleged deficiency. Accordingly, we are not
persuaded of Examiner error in the rejection of claim 21.
Regarding dependent claims 31 and 42, Appellants summarily assert
that the Examiner erred in finding that the additional features are taught by
Seo and Lin (Ans. 9-10, 21-22) or Seo alone (Ans. 10, 25). App. Br. 36, 39-
40. For similar reasons discussed above with respect to claim 3 related to
merely pointing out what a claim recites and then asserting that the reference
fails to teach the recited feature, we are not persuaded of Examiner error in
the rejection of claims 31 and 42.

CONCLUSION
Under § 103, the Examiner did not err in rejecting claims 1, 3, 4, 10,
20-23, 25-33, and 35-43.

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ORDER
The Examiner’s decision rejecting claims 1, 3, 4, 10, 20-23, 25-33,
and 35-43 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)(iv).

AFFIRMED

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