Ex Parte Wan et al

Patent Trial and Appeal Board

Nov 29, 2017

14197267 (P.T.A.B. Nov. 29, 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.
14/197,267 03/05/2014 Jing WAN P7485US00 7217
99963 7590 12/01/2017
DITTHAVONG & STEINER, P.C.
44 Canal Center Plaza
Suite 322
ALEXANDRIA, VA 22314
EXAMINER
SPALLA, DAVID C
ART UNIT PAPER NUMBER
2896
NOTIFICATION DATE DELIVERY MODE
12/01/2017 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):
docket@dcpatent.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte JING WAN,
ANDY WEI, JINPING LIU, XIANG HU,
DAE-HAN CHOI, DAE GEUN YANG,
CHURAMANI GAIRE, and AKSHEY SEHGAL
Appeal 2017-003059
Application 14/197,2671
Technology Center 2800
Before PETER F. KRATZ, GEORGE C. BEST, and BRIAN D. RANGE,
Administrative Patent Judges.
RANGE, Administrative Patent Judge.
DECISION ON APPEAL
SUMMARY
Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
decision rejecting claims 1—16. We have jurisdiction. 35 U.S.C. § 6(b).
We AFFIRM.
1 The Appellant is the applicant, GlobalFoundries Inc., who is also identified
as the real party in interest. Appeal Br. 1.
Appeal 2017-003059
Application 14/197,267
STATEMENT OF THE CASE2
Appellant describes the invention as relating to fabrication of
source/drain regions of field-effect transistors (FETs). Spec. 11. In
particular, the invention seeks to enable formation of source/drain regions
for FETs using a single reticle. Id. at 12. Claim 1 is illustrative of the
claimed subject matter:
1. A method comprising:
forming a first fin and a second fin above a substrate;
forming a gate crossing over the first fin and the second
fin;
removing portions of the first fin and the second fin on
both sides of the gate;
forming silicon phosphorous tops on the first fin and the
second fin in place of the removed portions;
removing the silicon phosphorous tops on the first fin; and
forming silicon germanium tops on the first fin in place of
the silicon phosphorous tops,
wherein portions of the first fin and the second fin beneath
the gate are not etched.
Appeal Br. 12 (Claims App.).
REFERENCES
The Examiner relies upon the prior art below in rejecting the claims
on appeal:
Wuetal. US 2013/0168771 A1 July4, 2013
(“Wu”)
2 In this Opinion, we refer to the Final Office Action dated October 23, 2015
(“Final Act.”), the Appeal Brief filed April 8, 2016 (“Appeal Br.”), the
Examiner’s Answer dated December 13, 2016 (“Ans.”), and the Reply Brief
filed December 27, 2016 (“Reply Br.”).
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Appeal 2017-003059
Application 14/197,267
Hung et al. US 2014/0361373 A1 Dec. 11, 2014
(“Hung”)
Obradovic et al. US 2015/0093868 Al Apr. 2, 2015
(“Obradovic”)
Cheng et al. US 2015/0145048 Al May 28, 2015
(“Cheng”)
REJECTIONS
The Examiner maintains the following rejections on appeal:
Rejection 1. Claims 1—7 and 9-15 under 35 U.S.C. § 103 as
unpatentable over Hung in view of Wu. Final Act. 2.
Rejection 2. Claim 8 under 35 U.S.C. § 103 as unpatentable over
Hung and Wu in further view of Obradovic. Id. at 4.
Rejection 3. Claim 16 under 35 U.S.C. § 103 as unpatentable over
Hung and Wu in further view of Cheng. Id. at 5.
ANALYSIS
We review the appealed rejections for error based upon the issues
identified by the Appellant and in light of the arguments and evidence
produced thereon. Cf. 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 examiner’s rejections”)). After considering
the evidence presented in this Appeal and each of Appellant’s arguments, we
are not persuaded that Appellant identifies reversible error. Thus, we affirm
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Appeal 2017-003059
Application 14/197,267
the Examiner’s rejections for the reasons expressed in the Final Office
Action and the Answer. We add the following primarily for emphasis.
Appellant argues all rejections together and do not present
substantively distinct arguments for any individual claims. See Appeal Br.
4, 10. Therefore, consistent with the provisions of 37 C.F.R.
§ 41.37(c)(l)(iv) (2013), we limit our discussion to claim 1, and all other
claims on appeal stand or fall together with claim 1.
The Examiner finds that Hung discloses forming two fins above a
substrate, forming a gate crossing over the fins, removing a portion of the
fins on both sides of the gate, and forming germanium tops on the first fin
where portions of the first and second fin beneath the gate are not etched.
Final Act. 2 (providing citations to Hung). The Examiner finds that Hung
does not disclose forming the fins so that one fin top comprises silicon
phosphorous (SiP) and the other fin top comprises silicon germanium. Id.
The Examiner finds, however, that Wu discloses a method for forming a
finFET array wherein masks are used to form SiP and SiGe tops of the fins.
Id. (citing Wu). The Examiner concludes that it would have been obvious to
modify Hung’s FET using Wu’s technique to provide “improved
performance for each transistor of a CMOS pair, while also enabling closer
placement of the finFETs with dissimilar channel materials, which increases
circuit density and reduces lengths of metallization wiring, thereby
improving overall performance of an integrated circuit. . . .” Id. at 3.
Appellant argues that Wu and Hung are not properly combinable
because Wu teaches forming gate 816 after formation of Ge on the tips of
the fins and after the removal of portions of the fins, because modification of
Wu would “teach away” from Wu, and because modifying Wu would alter
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Application 14/197,267
the principle of Wu. Appeal Br. 5—6. The Examiner’s rejection, however, is
based upon modification of Hung rather than modification of Wu. Ans. 2.
Accordingly, Appellant’s arguments regarding modification of Wu are not
persuasive because they do not fairly address the substance of the
Examiner’s rejection.
Appellant also argues that the sequence of the steps of Hung and Wu
are so substantially different that there is no reason to combine the teachings
of these references. Appeal Br. 6—8. However, the Examiner finds, for
example, that the “masking steps in Wu that are cited by the Examiner in the
rejection do not require the absence of a gate.” Ans. 5. The Examiner also
finds several reasons why a person having ordinary skill in the art would
have had been led to employ Wu’s teachings to modify Hung’s fins. Final
Act. 2—3; Ans. 2—8. For example, use of SiGe in conjunction with Hung
would have better carrier mobility, improve circuit density, and improve
performance. Final Act. 2—3. The end result would be a “denser, less
wasteful logic gate which gains the benefit of a strained channel.” Ans. 7.
Moreover, Hung already teaches using SiP or SiGe, and the Examiner finds
that modification of Hung by following Wu’s teachings would allow
construction of a CMOS device as known in the art. Id. at 5; Ans. 7.
Appellant does not persuasively rebut the Examiner’s findings that underlie
the Examiner’s obviousness conclusion.
In the Reply Brief, Appellant also argues that combining the teachings
of Hung and Wu would not achieve Hung’s stated goal of increasing stress
imposed on the channel region because Hung’s “formation of the gate prior
to processing the fins” are central to this goal in Hung. Reply Br. 6. This
argument does not persuasively rebut the Examiner’s rejection in view of the
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Application 14/197,267
evidence before us. The Examiner’s rejection retains formation of the gate
prior to processing fins just as Hung teaches. Ans. 5—6. While it is true that
the presence of the gate would prevent a portion of a fin covered by the gate
from being etched (Reply Br. 6), Hung teaches just such a procedure (Hung
Figs. 1, 2, 6, 9,137) and therefore indicates that the gate’s presence does not
defeat the goal of increasing stress. Appellant has not persuasively
explained why Hung’s goal of imposing stress on the channel region would
not be met or why this issue decisively weighs against the Examiner’s stated
rationales for combining the teachings of Hung and Wu.
DECISION
For the above reasons, we affirm the Examiner’s rejections of claims
1-16.
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
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