Ex Parte CHIU et al

Patent Trial and Appeal Board

Aug 7, 2017

13753867 (P.T.A.B. Aug. 7, 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.
13/753,867 01/30/2013 Han-Chin CHIU TSMP20121148US00 9163
43859 7590 08/09/2017
SLATER MATSIL, LLP/TSMC
17950 PRESTON ROAD, SUITE 1000
DALLAS, TX 75252
EXAMINER
ANYA, IGWE U
ART UNIT PAPER NUMBER
2891
NOTIFICATION DATE DELIVERY MODE
08/09/2017 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):
docketing @ slatermatsil. com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte TAIWAN SEMICONDUCTOR MANUFACTURING
COMPANY, LTD.1
Appeal 2016-005697
Application 13/753,8672
Technology Center 2800
Before ROMULO H. DELMENDO, BEVERLY A. FRANKLIN, and
N. WHITNEY WILSON, Administrative Patent Judges.
DELMENDO, Administrative Patent Judge.
DECISION ON APPEAL
Taiwan Semiconductor Manufacturing Company, Ltd., the Applicant
(hereinafter “Appellant”), appeals under 35 U.S.C. § 134(a) from the
Primary Examiner’s final decision to reject claims 1—20.3 We have
jurisdiction under 35 U.S.C. § 6(b).
1 Han-Chin Chiu, Chen-Hao Chiang, Chi-Ming Chen, and Chung-Yi Yu are
listed as the inventors (Application Data Sheet filed May 3, 2016).
2 Taiwan Semiconductor Manufacturing Company, Ltd. is identified as the
real party in interest (Appeal Brief filed August 19, 2015, hereinafter
“Appeal Br.,” 2).
3 Appeal Br. 6—15; Reply Brief filed May 10, 2016, hereinafter “Reply Br.,”
1—7; Final Office Action entered February 2, 2015, hereinafter “Final Act.,”
3—15; Examiner’s Answer entered March 11, 2016, hereinafter “Ans.,” 2—
13.
Appeal 2016-005697
Application 13/753,867
We affirm.
A. BACKGROUND
The subject matter on appeal relates to semiconductor devices and
their methods of manufacture (Specification, hereinafter “Spec.,” 1, 30;
Abstract). Figure 2C of the subject application is illustrative:
^200
U
216'
u
216*
'220
■--■214
^212
204-i -^210
”''-208
_ ''■-'206
"nx 202
Fig, 2C
Figure 2C above depicts a semiconductor device 200 after implantation 220
of a Group V species into source and drain regions 216 (shown in Figure
2B) to form source and drain regions 216’, wherein the semiconductor
device 200 further includes a passivation layer 214, a Group III—V nitride
compound layer 204 (made of a first buffer layer 206, a second buffer layer
208, a main Group III nitride compound layer 210, and a top Group III
nitride compound layer 212), and a substrate 202 (Spec. 15—18).
Representative claim 1 is reproduced from page 16 of the Appeal
Brief (Claims Appendix), with key limitations highlighted in bolded italics,
as follows:
1. A method of forming a semiconductor device, the method
comprising:
forming a III—V compound layer on a substrate;
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Application 13/753,867
forming a passivation layer over the III—V compound
layer;
implanting a main dopant into the III—V compound layer
to form source and drain regions, wherein the source and drain
regions extend into the passivation layer; and
implanting a group Vspecies within the source and drain
regions.
B. REJECTIONS ON APPEAL
On appeal, the Examiner maintains several rejections under pre-AIA
35 U.S.C. § 103(a), which are listed as follows:
I. Claims 1—7, 9, and 11 as unpatentable over Sheppard et
al.4 (hereinafter “Sheppard”) and Srinivasan;5
II. Claims 8, 10, and 12 as unpatentable over Sheppard,
Srinivasan, and Niiyama et al.6 (hereinafter “Niiyama”);
and
III. Claims 13—20 as unpatentable over Sheppard, Srinivasan,
and Suvorov.7
(Final Act. 3—15; Ans. 2—13.)
C. DISCUSSION
Rejection I. The Appellant provides separate arguments for claims 9
and 11 but otherwise argues the other claims (i.e., claims 1—7) together.
Therefore, we confine our discussion to claims 1 (representative of claims
1-7), 9, and 11. See 37 C.F.R. § 41.37(c)(l)(iv).
4 US 2008/0121895 Al, published May 29, 2008.
5 US 2013/0056793 Al, published March 7, 2013.
6 US 2009/0246924 Al, published October 1, 2009
7 US 2011/0092057 Al, published Apr. 21, 2011.
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Application 13/753,867
Claim 1:
The Examiner finds that Sheppard describes a method of forming a
semiconductor device including every limitation recited in claim 1 except
for implanting a Group V species within source and drain regions 31 (Final
Act. 3^4; Ans. 3) (referring to Figs. ID and IE, respectively). The
Examiner finds further, however, that Srinivasan teaches “implanting a
group V species contemporaneously with [a] main dopant into [a Group] III—
V compound layer for the benefit of preventing loss of [G]roup V elements
in the group III—V compound layer during a subsequent annealing process”
(Final Act. 4). Based on these findings, the Examiner concludes that “it
would have been obvious to one of ordinary skill in the art to combine the
teachings of Sheppard/Srinivasan et al. for the benefit of preventing loss of
[G]roup V elements in the [G]roup III—V compound layer” (id. ).
The Appellant contends that “Srinivasan fails to teach or suggest
implanting a [G]roup V species within source and drain regions at least
because Srinivasan fails to teach or suggest the existence of source and drain
regions” (Appeal Br. 7). According to the Appellant, absent such a teaching,
Srinivasan would not have suggested implanting a Group V species within
source and drain regions, as required by claim 1 (id.). The Appellant argues
that, although Sheppard implies that regions 31 are source and drain regions,
“Sheppard appears to be completely silent with respect to any implantation
into regions 31 once these regions actually exist” (id. at 8).
The Appellant’s arguments fail to identify reversible error in the
Examiner’s rejection. In re Jung, 637 F.3d 1356, 1365 (Fed. Cir. 2011).
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Application 13/753,867
The Appellant does not dispute the Examiner’s findings regarding the
scope and content of Sheppard’s disclosure (Appeal Br. 6—8). Specifically,
Sheppard’s Figure ID is reproduced below:
FIG, ID
Sheppard’s Figure ID above depicts a semiconductor device in production,
wherein the device includes a substrate 10, a channel layer 20 in the form of
a Group III nitride layer, a surface layer 22 also in the form of a Group III
nitride layer, a protective layer 24 in the form of, e.g., SixNy, Si02, and/or
SiON, and implanted regions 31 (Sheppard, Tflf 38, 39, 42, 54, 59, 60). As
the Appellant appears to acknowledge (Appeal Br. 8), a person having
ordinary skill in the art would have drawn a reasonable inference that
Sheppard’s implanted regions 31 are source and drain regions. Thus, we
discern no error in the Examiner’s determination (Final Act. 4) that
Sheppard describes every step recited in claim 1 except for the step of
“implanting a [GJroup V species within the source and drain regions.”
Sheppard teaches that “after impurities [dopants] are implanted into a
semiconductor layer, it may be desirable to anneal the implanted impurities
at a high temperature, i.e., a so-called activation anneal” to “repair damage
caused by the implantation of high-energy ions into the semiconductor
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Application 13/753,867
lattice” (Sheppard, Tflf 5, 8). Srinivasan teaches, however, that heating a
Group III—V compound such as GaN results in surface decomposition
(Srinivasan, | 6). To address this problem, Srinivasan teaches that the doped
Group III—V compound layer can be implanted with a predetermined
concentration of Group V materials at or near the surface of the Group III—V
compound layer to help prevent decomposition of the surface during
subsequent annealing (Srinivasan, || 9, 34, 37).
Given these findings, we are in complete agreement with the
Examiner that a person having ordinary skill in the art would have combined
Sheppard and Srinivasan in the manner claimed by the inventors. Because
Sheppard contemplates annealing (Sheppard, 5, 8), a person having
ordinary skill in the art would have had a sufficient reason to implant a
Group V species into Sheppard’s Group III—V nitride layers, including the
doped source and drain regions 31, in order to prevent any surface
decomposition of the Group III—V nitride layers during annealing, as
suggested by Srinivasan flflf 6, 9, 34, 37). KSR Int'l Co. v. Teleflex Inc., 550
U.S. 398, 420 (2007) (“[I]n many cases a person of ordinary skill will be
able to fit the teachings of multiple patents together like pieces of a
puzzle.”).
For these reasons, we agree with the Examiner’s obviousness
conclusion as to claim 1.
Claim 9:
The Appellant argues that it attempted to incorporate the subject
matter of claim 9 into claim 1 by an Amendment filed on April 1, 2015, but
the Examiner denied entry of that Amendment (Appeal Br. 8; see also
Advisory action entered May 4, 2015). In addition, the Appellant contends
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Application 13/753,867
that the Examiner entered a new ground of rejection in the Advisory Action
(Appeal Br. 9). These issues, however, are petitionable rather than
appealable and, therefore, should have been raised by way of a timely
petition pursuant to 37 C.F.R. § 1.181. See M.P.E.P. §§ 714.13, 1002.02(c).
On the substantive merits, the Appellant relies on the same arguments
offered in support of claim 1 (Appeal Br. 8). We have already found these
argument to be unpersuasive.
In addition, the Appellant argues that the Examiner admitted that
Srinivasan implants Group V dopants contemporaneously with the main
dopants, and, therefore, the reference would not have taught or suggested
implanting a Group V species within the source and drain regions after
implanting the main dopants, as required by claim 9 (id. at 8—9). We find
this argument unpersuasive because, as the Examiner explains (Ans. 6),
“contemporaneous” is not necessarily synonymous with “simultaneous” in
context. Indeed, the Appellant’s dictionary definition (“existing or
happening during the same time period”) on page 9 of the Appeal Brief
supports the Examiner’s position.
For these reasons, we sustain the Examiner’s rejection of claim 9.
Claim 11:
The Appellant contends that Srinivasan would not have suggested “a
ratio of the first dopant to the second dopant ranging from about 1,000:1 to
about 10:1” as recited in claim 11 because the reference does not disclose a
dopant ratio within source and drain regions (Appeal Br. 10). In addition,
the Appellant argues that Srinivasan is silent regarding the nitrogen
concentration prior to implantation with additional nitrogen (Group V
species), and, therefore, Srinivasan cannot reasonably be interpreted as
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Application 13/753,867
providing any information regarding “a ratio of the first dopant to the second
dopant” (id. at 11).
The Appellant’s arguments are unpersuasive for the reasons given by
the Examiner (Ans. 3—4). As the Examiner finds (id. at 3), Srinivasan
teaches implanting a p-type Group III—V compound layer with a main
dopant such as Mg in an activated Mg concentration of about 1x1017 cm'3 or
above and may have a total Mg concentration of about lxlO20 cm'3 flflf 34—
36). Srinivasan further teaches that a p-type GaN layer may be implanted
into the surface with nitrogen (Group V species) to obtain a total nitrogen
concentration of about 1011 ions/cm2 to about 1021 ions/cm2 flflf 37—38).
Because the main dopant is Mg, and not nitrogen, Srinivasan’s Mgmitrogen
ratios for nitrogen implantation to a depth of 5—5000 nm overlap those
recited in claim 11. Therefore, the claimed subject matter would have been
obvious to a person having ordinary skill in the art. In re Peterson, 315 F.3d
1325, 1329 (Fed. Cir. 2003) (“A prima facie case of obviousness typically
exists when the ranges of a claimed composition overlap the ranges
disclosed in the prior art.”).
Moreover, a person having ordinary skill in the art would have
discovered the optimum or workable ranges of main dopant and Group V
dopant concentrations, which are result-effective variables, as a matter of
routine experimentation or optimization. Peterson at 1330 (“The normal
desire of scientists or artisans to improve upon what is already generally
known provides the motivation to determine where in a disclosed set of
percentage ranges is the optimum combination of percentages.”); In re Aller,
220 F.2d 454, 456 (CCPA 1955) (“[Wjhere the general conditions of a claim
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Application 13/753,867
are disclosed in the prior art, it is not inventive to discover the optimum or
workable ranges by routine experimentation.”).
For these reasons, we sustain the rejection of claim 11.
Rejection II. The Appellant contends that, assuming Niiyama is
properly combined with Sheppard and Srinivasan, “Niiyama fails to cure the
deficiencies of Sheppard and Srinivasan” (Appeal Br. 12). Because (i) the
Appellant does not explain why Niiyama cannot be combined with Sheppard
and Srinivasan and (ii) the Examiner’s combination of Sheppard and
Srinivasan is not deficient, we sustain Rejection II for the same reasons
discussed above for Rejection I.
Rejection III. The Appellant relies on arguments similar to those
presented against Rejection I, adding only that Suvorov does not cure the
alleged deficiencies in the combination of Sheppard and Srinivasan (Appeal
Br. 13—14). Because the Appellant’s arguments against Rejection I are
unpersuasive, we sustain Rejection III for the same reasons discussed above
in our discussion of Rejection I.
D. SUMMARY
Rejections I—III are sustained. Therefore, the Examiner’s final
decision to reject claims 1—20 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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