TEXAS INSTRUMENTS INCORPORATED

Patent Trials and Appeals Board

Jul 16, 2021

2020006730 (P.T.A.B. Jul. 16, 2021)

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.
15/674,266 08/10/2017 Mahalingam Nandakumar TI-63531.2 8015
23494 7590 07/16/2021
TEXAS INSTRUMENTS INCORPORATED
P O BOX 655474, MS 3999
DALLAS, TX 75265
EXAMINER
MUNOZ, ANDRES F
ART UNIT PAPER NUMBER
2894
NOTIFICATION DATE DELIVERY MODE
07/16/2021 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):
uspto@ti.com
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________
BEFORE THE PATENT TRIAL AND APPEAL BOARD
____________
Ex parte MAHALINGAM NANDAKUMAR, WAYNE BATHER,
and NARENDRA SINGH MEHTA
____________
Appeal 2020-006730
Application 15/674,266
Technology Center 2800
____________
Before LINDA M. GAUDETTE, JAMES C. HOUSEL, and
DEBRA L. DENNETT, Administrative Patent Judges.
DENNETT, Administrative Patent Judge.
DECISION ON APPEAL1
STATEMENT OF THE CASE
Pursuant to 35 U.S.C. § 134(a), Appellant2 appeals from the
Examiner’s decision to reject claims 11 and 12 of Application 15/674,266,

1 In our Decision, we refer to the Specification (“Spec.”) of Application No.
15/674,266 filed Aug. 10, 2017; the Final Office Action dated Feb. 14, 2020
(“Final Act.”); the Appeal Brief filed Apr. 21, 2020 (“Appeal Br.”); and the
Examiner’s Answer dated July 2, 2020 (“Ans.”). Appellant did not file a
Reply Brief.
2 “Appellant” refers to “applicant” as defined in 37 C.F.R. § 1.42. Appellant
identifies Texas Instruments Incorporated as the real party in interest.
Appeal Br. 3.
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which constitute all the claims pending in this application. We have
jurisdiction under 35 U.S.C. § 6(b).
For the reasons set forth below, we AFFIRM.
BACKGROUND
The subject matter of the invention relates to the fabrication of a
semiconductor transistor using a cap layer during the source/drain anneal
process. Spec. ¶ 2. According to the Specification, the cap layer is used
during the fabrication process to impart stress into the gate electrode during
the source/drain anneal process. Spec. ¶ 14. The cap layer of the invention
may be implanted with an electrically neutral species such as Ar. Spec.
¶ 16.
Claim 11, reproduced below, represents the claimed subject matter:
11. An integrated circuit comprising:
a cap layer comprising silicon and carbon in direct
contact with unannealed source/drain regions that are implanted
with dopants, source/drain sidewalls, and a gate electrode of a
transistor;
wherein said cap layer contains an electrically neutral
species.
Appeal Br. 21 (Claims App.).

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REFERENCES
The Examiner relies on the following prior art in rejecting claims 11
and 12 as obvious under 35 U.S.C. § 103(a):
Name Reference Date
Samavedam et al.
(“Samavedam”)
US 2004/0023478 A1 Feb. 5, 2004
Ng et al. (“Ng”) US 2005/0104095 A1 May 19, 2005
Borland et al.
(“Borland”)
US 2005/0202657A1 Sept. 15, 2005
REJECTIONS
The Examiner maintains rejections of the claims under 35 U.S.C.
§ 103(a)3 as follows: (1) claim 11 over Ng in view of Samavedam; (2) claim
12 over Ng in view of Samavedam and Borland; (3) claim 11 over
Samavedam in view of Ng; and (4) claim 12 over Samavedam in view of Ng
and Borland. Final Act. 2–5.
DISCUSSION
We review the appealed rejections for error based upon the issues
identified by Appellant and in light of the arguments and evidence produced
thereon. Ex parte Frye, 94 USPQ2d 1072, 1075 (BPAI 2010) (precedential),
(cited with approval in In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011))
(“[I]t has long been the Board’s practice to require an applicant to identify
the alleged error in the [E]xaminer’s rejections.”). After considering the
evidence presented in this Appeal and each of Appellant’s arguments, we are

3 Because this application is a divisional of an application filed before the
March 16, 2013, effective date of the America Invents Act, we refer to the
pre-AIA version of the statute.
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not persuaded that Appellant identifies reversible error. Thus, we affirm the
Examiner’s rejections for the reasons expressed in the Final Office Action
and the Answer. We add the following primarily for emphasis.
For each of the four rejections, the Examiner repeats the same
findings regarding Ng and Samavedam, and Appellant repeats the same
arguments in opposition to those findings. Compare Final Act. 2–3, with id.
at 4; Appeal Br. 6–9, with id. at 8–11; Ans. 6–12. with id. at 12–15.
Therefore, we focus on the rejection of claim 11 over Ng in view of
Samavedam as representative of the claims, and address the differences in
the rejections where necessary.
The Examiner finds that Ng teaches an integrated circuit comprising a
cap layer comprising silicon and carbon in direct contact with a substrate,
source/drain sidewalls, and a gate electrode of a transistor, wherein the cap
layer contains Ge, an electrically neutral species. Final Act. 2–3.
FIG. 4 of Ng is reproduced below:

FIG. 4 of Ng depicts substrate 10 having first spacer 24 formed along
sidewalls of gate stacks 20, 22. Ng ¶¶ 15–17, 47. Liner 28 is formed on the
surface of substrate 10 conformally covering gate stacks 20, 22 and first
space 24. Id. ¶ 47. Liner 28 may comprise an etch resistant material such as
SiC. Id. ¶ 48. Ion 32 is implanted into the surface of substrate 10. Id. ¶ 50.
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The Examiner identifies elements 24 and 28 as the cap layer, 30 as the
source/drain sidewalls, and 20 as a gate electrode of a transistor, and 32 as
an electrically neutral species. Final Act. 2–3. The Examiner finds that Ng
fails to disclose the cap layer in direct contact with unannealed source/drain
regions that are implanted with dopants. Id. at 3.
The Examiner finds that Samavedam teaches a cap layer in direct
contact with unannealed source/drain regions that are implanted with
dopants. Final Act. 3.
FIG. 6 of Samavedam is reproduced below:

FIG. 6 of Samavedam is a partial cross sectional view of a partially
completed semiconductor device after several processing steps have been
completed. Samavedam ¶¶ 8–13. Semiconductor substrate 102 includes
first well 104 and second well 106. Id. ¶ 20. Gate dielectric 108 is formed
over first and second wells 104 and 106. Id. First metal layer 110, second
metal layer 114, and silicon containing layer 116 are patterned to form first
gate 120 and second gate 122. Id. ¶ 29. First spacers 124 are formed along
sides of both gates. Id. ¶ 36. Extension regions 126 and 130 are formed
self-aligned to first gate 120 and second gate 122, respectively, the oxide
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line 134 is deposited over the device. Id. ¶ 36. An anneal is performed
afterwards to diffuse the extension and source/drain regions to the desired
profile and to activate the dopants. Id. ¶ 39.
The Examiner identifies element 134 as a cap layer in direct contact
with unannealed source/drain regions 126/140 that are implanted with
dopants. Final Act. 3.
The Examiner concludes that it would have been obvious to one of
ordinary skill in the art at the time of the invention to include Samavedam’s
arrangement in Ng’s device to arrive at the claimed invention so as to enable
formation of source/drain regions adjacent a gate electrode and/or include
unannealed source/drain regions to minimize thermal damage and anneal
only after all source/drain related implants are completed. Id. at 3.
Appellant argues that Ng teaches that the source/drain regions are not
implanted with dopants, as required by claim 11. Appeal Br. 6–7. Appellant
also argues that Ng’s elements 24 and 28 are not the “claimed cap layer
containing Ar.” Id. at 7. Regarding Samavedam, Appellant argues the
reference does not teach a cap layer comprising silicon and carbon in direct
contact with unannealed source/drain regions that are implanted with
dopants, source/drain sidewalls, and a gate electrode of a transistor. Id. at 7–
8. Appellant argues that Samavedam teaches the cap layer is in direct
contact with a second overlying cap formed of a silicon containing layer,
which is formed over a first gate and a second gate. Appellant also argues
that Samavedam teaches that the cap is silicon dioxide, but not silicon and
carbon as required by claim 11. Id. at 8.
Appellant argues that one of ordinary skill in the art would not have
combined Samavedam’s capped dual metal gate structure with Ng’s
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structure whose gate comprises polysilicon, as “Samavedam [] teaches that
‘the use of polysilicon [gate] structures is becoming unfeasible’ and
problematic.” Id. Appellant argues that one of ordinary skill in the art
would not have combined a capped dual metal gate structure having
source/drain regions that are formed by implementation through the thinned
oxide liner (as in Samavedam) with a transistor structure whose source/drain
is formed by conductive material formed in source/drain regions as a silicide
(as in Ng). Id. at 8–9.
Appellant’s arguments are unpersuasive of reversible error in the
rejections.
We agree with the Examiner that Appellant argues against the
references individually. Ans. 8–11. “Non-obviousness cannot be
established by attacking references individually where the rejection is based
upon the teachings of a combination of references.” In re Merck & Co., 800
F.2d 1091, 1097 (Fed. Cir. 1986). The Examiner does not rely on Ng as
teaching the entirety of what Appellant identifies as missing from the
reference. Compare, e.g., Final Act. 3 (“Ng fails to disclose the cap layer in
direct contact with unannealed [sic] source/drain regions that are implanted
with dopants.”), with Appeal Br. 6 (“Ng [] does not teach a cap layer . . . in
direct contact with unannealed source/drain regions that are implanted with
dopants . . . .”). The same is true of Samavedam. Each reference cited by
the Examiner must be read, not in isolation, but for what it fairly teaches in
combination with the prior art as a whole. See Merck, 800 F.2d at 1097.
Here, the Examiner explains how all of the limitations of claim 11 are taught
by either Ng, Samavedam, or both, and provides adequate reasoning of why
one of ordinary skill in the art would combine the teachings. “One of
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ordinary skill in the art need not see the identical problem addressed in a
prior art reference to be motivated to apply its teachings.” Cross Med.
Prods., Inc. v. Medtronic Sofamor Danek, Inc., 424 F.3d 1293, 1323 (Fed.
Cir. 2005). The Examiner’s explanation of the reasons a person of ordinary
skill in the art would have had to combine the prior art teachings is sufficient
taking into account “the inferences and creative steps that a person of
ordinary skill in the art would employ.” KSR Int’l Co. v. Teleflex Inc., 550
U.S. 398, 418 (2007).
Appellant’s argument that one of ordinary skill in the art would not
have combined Ng’s gate structure with Samavedam’s capped dual metal
gate structure is also unavailing. See Appeal Br. 8. It is well established
that the obviousness inquiry does not ask “whether the references could be
physically combined but whether the claimed inventions are rendered
obvious by the teachings of the prior art as a whole.” 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) (“The test for obviousness is not whether the features of a
secondary reference may be bodily incorporated into the structure of the
primary reference”); 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.”).
Moreover, arguments of counsel cannot take the place of factually
supported objective evidence. See, e.g., In re Huang, 100 F.3d 135, 139–40
(Fed. Cir. 1996); In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984).
Appellant references Samavedam’s statement that “[t]he use of polysilicon
gate structures is becoming unfeasible as gate dielectric thicknesses steadily
decrease,” but this is insufficient to constitute teaching away from a
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combination of the references. See In re Mouttet, 686 F.3d 1322, 1334 (Fed.
Cir. 2012) (“This court has further explained that just because better
alternatives exist in the 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))).
We sustain the rejection of claim 11 as obvious over Ng in view of
Samavedam.
Rejection of claim 12 as obvious over Ng in view of Samavedam and
Borland
Claim 12 depends from claim 11 and further recites, “wherein said
electrically neutral species comprises Ar.” Appeal Br. 21 (Claims App.).
The Examiner’s findings regarding Ng and Samavedam are the same
for claims 11 and 12. The Examiner finds that Borland discloses argon (Ar)
is an electrically neutral species, and notes that the reference discloses
materials that overlap those of Ng. Final Act. 3–4. The Examiner concludes
that it would have been obvious to one of ordinary skill in the art at the time
of the invention to include the Ar of Borland in the device of Ng and
Samavedam to (i) damage portions of the cap layer prior to etching and
damage, and/or (ii) damage and pre-amorphize a layer. Id. In addition, the
Examiner determines that inclusion of Borland’s Ar would have been “use
of conventional materials to perform their known function,” thus, prima
facie obvious. Id. at 4.
Appellant contends that Borland teaches use of Ar in a pre-
amorphizing implant, which is an ion implantation step done prior to a
doping step. Appeal Br. 12. Appellant argues, therefore, that Borland
teaches the use of Ar in an undoped semiconductor, and does not teach
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implantation of Ar in a previously doped capping layer comprising silicon
and carbon. Id.
We agree with the Examiner’s position that Appellant attempts to
show nonobviousness of claim 12 by attacking references individually and
requiring bodily incorporation of Borland into Ng combined with
Samavedam. See Ans. 16. The Examiner relies on Samavedam, not
Borland, to disclose source/drain regions implanted with dopants. See Final
Act. 3. Borland discloses that Ar is an electrically neutral species used for
implanting a semiconductor. Borland ¶ 3. Appellant’s arguments do not
address the Examiner’s reasons for combining the references, and thus fail to
overcome the obviousness rejection.
Rejection of claim 11 as obvious over Samavedam in view of Ng and
of claim 12 as obvious over Samavedam in view of Ng and Borland
The Examiner’s findings and Appellant’s arguments in these
rejections are substantially identical to those made with Ng as the primary
reference. For the reasons given above, we sustain the rejections in which
Samavedam is the primary reference.
DECISION SUMMARY
In summary:
Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
11 103(a) Ng, Samavedam 11
12 103(a) Ng, Samavedam, Borland 12
11 103(a) Samavedam, Ng 11
12 103(a) Samavedam, Ng, Borland 12
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Claims
Rejected
35 U.S.C.
§
Reference(s)/Basis Affirmed Reversed
Overall
Outcome
11, 12
TIME PERIOD FOR RESPONSE
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136(a).
AFFIRMED