Ex Parte Chang et al

Patent Trials and Appeals Board

Apr 16, 2019

13921273 - (D) (P.T.A.B. Apr. 16, 2019)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/921,273 06/19/2013
107476 7590 04/18/2019
Eschweiler & Potashnik, LLC
Rosetta Center
629 Euclid Ave., Suite 1000
Cleveland, OH 44114
FIRST NAMED INVENTOR
Kuei-Sung Chang
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
ATTORNEY DOCKET NO.
TSMCP298US
(TSMC2013-0452
CONFIRMATION NO.
9321
EXAMINER
BRASFIELD, QUINTON A
ART UNIT PAPER NUMBER
2814
NOTIFICATION DATE DELIVERY MODE
04/18/2019 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@eschweilerlaw.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte KUEI-SUNG CHANG and TE-HAO LEE
Appeal2018-003507 1
Application 13/921,273
Technology Center 2800
Before CATHERINE Q. TIMM, JEFFREY T. SMITH, and
LILAN REN, Administrative Patent Judges.
SMITH, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal under 35 U.S.C. § 134 from a final rejection of
claims 1--4, 6, 7, 9-12, 15, 21, 22, and 25-31. We have jurisdiction under
35 U.S.C. § 6.
We REVERSE.
1 Appellant and the real party in interest is Taiwan Semiconductor
Manufacturing Company, Limited. (App. Br. 1.)
Appeal2018-003507
Application 13/921,273
Appellant's invention is generally directed to a method of etching a
narrow gap using one or more parallel releasing structures to improve
etching performance, and an associated apparatus. (Spec. ,r 11.) Claims 1
and 10 illustrate the subject matter on appeal and are reproduced below:
1. A method of etching a gap within a semiconductor
substrate, comprising:
providing a semiconductor substrate comprising a trench
filled with a sacrificial material having an exposed upper
surface;
forming a plurality of parallel releasing structures within
the semiconductor substrate, wherein the plurality of parallel
releasing structures comprise multiple depressions vertically
extending into the semiconductor substrate to contact a sidewall
of the sacrificial material and laterally protruding outward from
a first side of the trench at positions separated along a length of
the trench; and
performing an etching process to simultaneously remove
the sacrificial material from the gap along multiple directions.
10. A method of etching a gap within a semiconductor
substrate, comprising:
selectively etching a semiconductor substrate to form a
trench within the semiconductor substrate;
forming sacrificial material onto sidewalls of the trench,
resulting in a gap comprising the sacrificial material;
filling the gap within the semiconductor substrate with a
structure material contacting a sidewall and an upper surface of
the sacrificial material;
etching the structure material within the gap to form one
or more parallel releasing structures comprising depressions
within the semiconductor substrate that contact the sacrificial
material within the gap; and
removing the sacrificial material from the gap by
simultaneously etching the sacrificial material along multiple
directions.
2
Appeal2018-003507
Application 13/921,273
The following rejections are presented for our review:
I. Claims 1, 2, 4, 6, 7, 9, 26, and 28 rejected under 35 U.S.C.
§ 102( a )(1) as anticipated by Gogoi (US 2007 /002663 6 A 1, pub 1.
Feb. 1, 2007).
II. Claims 3 and 7 rejected under 35 U.S.C. § 103 as unpatentable
over Gogoi in view of Ayazi (US 2010/0176489 Al, publ. July 15,
2010).
III. Claims 10, 12, 27, and 29 rejected under 35 U.S.C. § 103 as
unpatentable over Kim (US 2014/0179092 Al, publ. June 26, 2014) in
view of Ma (US 2006/0027891 Al, publ. Feb. 9, 2006).
IV. Claims 11 and 15 rejected under 35 U.S.C. § 103 as unpatentable
over Kim in view of Ma and further in view of Ayazi.
V. Claims 21, 22, 24, 25, and 30 rejected under 35 U.S.C. § 103 as
unpatentable over Gogoi in view of Fukuda (US 2006/0185980 Al,
publ. Aug. 24, 2006).
VI. Claim 27 rejected under 35 U.S.C. § 103 as unpatentable over
Kim in view of Ma and further in view of Fukuda.
VII. Claim 31 rejected under 35 U.S.C. § 103 as unpatentable over
Gogoi in view of Fukuda and further in view of Ayazi.
The complete statement of the rejections on appeal appear in the Final
Office Action. (Final Act. 3-13.)
OPINION
Rejection I
Claims 1, 2, 4, 6, 7, 9, 26, and 28 are rejected as anticipated by Gogoi.
We limit our discussion to independent claim 1.
3
Appeal2018-003507
Application 13/921,273
The Examiner found Gogoi describes a method of etching a gap
within a semiconductor substrate, wherein the semiconductor substrate
comprises a trench filled with a sacrificial material having an exposed upper
surface. (Final Act. 3.) Gogoi Figure 6 is reproduced below:
146 103 ~ .148
150 lJ 152 ~ l!f4 !f It6 1f8 1J68
""""""' \ ""'"" ! """"""""""""""''""""""""""" ' """"""""""""-- ---I- ' ' -'""
~11-= \,----~
I
I 128
I
// / o·' / / ,/ / / / /_/ / / / // / / / / ,,- / / / / / / / _/ / / / / ,// / .,/ / ,/
!
HO
126
Gogoi Figure 6 illustrating a cross-sectional view of a MEM device
The Examiner found Gogoi describes the semiconductor substrate
(124) comprising a trench (150) filled with a sacrificial material (158)
having an exposed upper surface comprising a plurality of parallel releasing
structures (150, 152, 154, 156) formed within the semiconductor substrate.
(Final Act. 3.)
Appellant argues Gogoi fails to anticipate forming a plurality of
parallel releasing structures comprising multiple depressions laterally
protruding outward from a first side of a trench at positions separated along
a length of the trench as recited in claim 1. (App. Br. 4--5.)
We agree with Appellant that Gogoi fails to describe the claimed
method because the Examiner has not established that Gogoi describes
forming a plurality of parallel releasing structures laterally protruding
outward from the first side of a trench as required by independent claim 1.
Specification Figure 3B is reproduced below:
4
Appeal2018-003507
Application 13/921,273
316~
302
Specification Figure 3B, reproduced above, depicts a prospective view of
semiconductor substrate 302 comprising a trench 104 (filled with sacrificial
material 304 (See Fig. 3A)) and a plurality of parallel releasing structures,
106a and 106b, laterally protruding outward from the side of the filled trench
104.
The Examiner relied upon the Figures of Gogoi as providing the
anticipatory description of the claimed invention. The Examiner determined
Gogoi trench 150 is equivalent to the filled trench 104 of the present
invention and trenches 150, 152, 154, and 156 are equivalent to the parallel
releasing structures 106 of the present invention. (Final Act. 3.) Figures 2-
12 of Gogoi provide the lateral view of the semiconductor substrate. The
figures illustrate substrates that comprise trenches, some including sacrificial
materials. It cannot be discerned from the depictions that the structures
(150, 152, 154, 156) protrude outward from a trench as required by the
subject matter of independent claim 1. The Figures depict trenches 152,
154, and 156 as separated from trench 150 by active material 128, however,
these trenches do not protrude outward from trench 150.
5
Appeal2018-003507
Application 13/921,273
For the foregoing reasons and those presented by Appellant, the
Examiner has failed to establish that Gogoi anticipates the subject matter of
independent claim 1 and dependent claims 2, 4, 6, 7, 9, 26, and 28.
Rejections II, V, and VII
We do not sustain the Examiner's rejection of independent claim 1
for the reasons presented by Appellant and given above. We, likewise, do
not sustain the Examiner's decision to reject dependent claims 3, 7, 21, 22,
24, 25, 30, and 31, since these rejections are premised on the Examiner's
misinterpretation of Gogoi. We need not reach whether the Examiner's
reliance on other references in addition to Gogoi for the rejection of the
dependent claims was supported by the evidence of record. The Examiner
cited the additional references to address limitations different from
independent claim 1.
Rejection III
Claims 10, 12, 27, and 29 are rejected under 35 U.S.C. § 103 as
unpatentable over the combination of Kim and Ma. We limit our discussion
to independent claim 10.
The Examiner found Kim teaches a method for fabricating a
semiconductor device, which comprises etching a semiconductor substrate
(12) to form a trench (13) within the semiconductor substrate; forming
sacrificial material ( 14) onto sidewalls of the trench, resulting in a gap
comprising the sacrificial material; filling the gap within the semiconductor
substrate with a structure material (15A) contacting a sidewall and an upper
surface of the sacrificial material; etching the structure material ( 15C) within
6
Appeal2018-003507
Application 13/921,273
the gap; and removing the sacrificial material (14) from the gap by
simultaneously etching the sacrificial material along multiple directions (see
Figs. lA-lG). (Final Act. 7.) The Examiner found Kim does not show
etching the structure material within the gap to form one or more parallel
releasing structures comprising depressions within the semiconductor
substrate that contact the sacrificial material within the gap. The Examiner
found Ma teaches etching a structure material to form a plurality of parallel
releasing structures, e.g., vertical and horizontal gaps where desired, for
example, in the fabrication of one or more MEMS (Ma ,r,r 52 and 57) (Final
Act. 7-8.) The Examiner concluded it would have been obvious to etch the
structure material within the gap to form one or more parallel releasing
structures comprising depressions within the semiconductor substrate that
contact the sacrificial material within the gap in the device of Kim to form
vertical and horizontal gaps where desired, for example, in the fabrication of
one or more MEMS (Ma ,r,r 52 and 57) (Final Act. 8.)
Appellant argues Kim fails to teach removing a sacrificial material
from a gap by simultaneously etching the sacrificial material along multiple
directions, as recited in claim 10. (App. Br. 9.) Appellant argues one of
ordinary skill would not have been motivated to etch the polysilicon layer to
form gaps because Kim teaches forming a polysilicon layer 15 that does not
have gaps or voids along the sides of the polysilicon. (App. Br. 10-11; Kim
,r 3, Fig. 2A.) Appellant concludes Kim teaches that it is not desirable to
form voids or gaps within the polysilicon layer 15. (App. Br. 11.)
Having considered the respective positions advanced by the Examiner
and Appellant in light of this appeal record, we reverse the Examiner's
rejection for the reasons set forth in the Appeal Brief.
7
Appeal2018-003507
Application 13/921,273
The Examiner has not adequately explained why the combination of
Kim and Ma would have rendered obvious a method of etching a gap within
a semiconductor device as required by independent claim 10. The Examiner
has not adequately explained why one of ordinary skill would have been
motivated to etch the polysilicon layer to form gaps since Kim teaches
forming a polysilicon layer that does not have gaps or voids along the sides
of the polysilicon. (Kim ,r 3, Fig. 2A.) Thus, the Examiner has not
adequately explained why one of ordinary skill would have been motivated
to etch the polysilicon layer of Kim to simultaneously remove the sacrificial
material from a gap along multiple directions as recited in claim 10. The
Examiner has not adequately explained why one of ordinary skill would
have looked to the teachings of Ma to modify the teachings of Kim.
For the foregoing reasons and those presented by Appellant, the
Examiner has failed to establish that the combination of Kim and Ma renders
obvious the subject matter of independent claim 10 and dependent claims
12, 27, and 29.
Rejections IV and VI
We do not sustain the Examiner's rejection of independent claim 10
for the reasons presented by Appellant and given above. We, likewise, do
not sustain the Examiner's decision to reject dependent claims 11, 15, and
27, since these rejections are premised on the Examiner's reliance on the
combination of Kim and Ma. We need not reach whether the Examiner's
reliance on other references in addition to Kim and Ma for the rejection of
the dependent claims was supported by the evidence of record. The
8
Appeal2018-003507
Application 13/921,273
Examiner cited the additional references to address limitations different from
independent claim 10.
Accordingly, we reverse the 35 U.S.C. § 102(a)(l) and
§ 103 rejections of claims 1--4, 6, 7, 9-12, 15, 21, 22, and 25-31 for the
reasons given above.
DECISION
The Examiner's§ 102(a)(l) and§ 103 rejections of claims 1--4, 6, 7,
9-12, 15, 21, 22, and 25-31 are reversed.
REVERSED
9