Ex Parte Yan et al

Patent Trial and Appeal Board

Dec 4, 2017

13074888 (P.T.A.B. Dec. 4, 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.
13/074,888 03/29/2011 Jiang Yan INF 2008 P 50530 US01 1624
48154 7590 12/06/2017
SLATER MATSIL, LLP/Infineon
17950 PRESTON ROAD
SUITE 1000
DALLAS, TX 75252
EXAMINER
LEE, JAE
ART UNIT PAPER NUMBER
2899
NOTIFICATION DATE DELIVERY MODE
12/06/2017 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 JIANG YAN, ROLAND HAMPP,
JIN-PING HAN, MANFRED ELLER,
and ALOIS GUTMANN
Appeal 2017-004197
Application 13/074,888
Technology Center 2800
Before TERRY J. OWENS, CHRISTOPHER C. KENNEDY, and
MICHAEL G. McMANUS, Administrative Patent Judges.
OWENS, Administrative Patent Judge.
DECISION ON APPEAL
STATEMENT OF THE CASE
The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1, 4, 5, 7, 8, 10, 11, 13-16, 20-26, and 30-33. We have
jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellants claim a semiconductor device. Claim 1 is illustrative:
1. A semiconductor device comprising:
a workpiece including a conductive region;
a first insulating material disposed over the workpiece;
a first opening for a first portion of a conductive feature
disposed within the first insulating material;
Appeal 2017-004197
Application 13/074,888
a second insulating material disposed over the first
insulating material;
a second opening for a second portion of the conductive
feature disposed in the second insulating material; and
a conductive material filling the first opening and the
second opening to form the conductive feature, wherein the
conductive feature is electrically coupled to the conductive
region, wherein the conductive feature comprises substantially a
first width in a bottom portion of the second insulating material,
wherein the conductive material comprises a liner continuously
lining sidewalls of the first opening and the second opening and
a conductive fill material disposed on the liner and completely
filling the first opening and the second opening, wherein a
volume of the conductive fill material in the first opening
measured at a cross-sectional area parallel to the first width is
substantially constant from a bottom portion of the first
insulating material to the bottom portion of the second
insulating material, wherein a volume of the conductive fill
material in the second opening measured at a cross-sectional
area parallel to the first width increases from the bottom portion
of the second insulating material to a top portion of the second
insulating material, wherein the conductive feature comprising
the first portion and the second portion is a single integral via,
wherein the first portion of the conductive feature and the
second portion of the conductive feature are part of the final
form of the semiconductor device.
Zhang
The References
US 2005/0287722 A1 Dec. 29, 2005
Koutny US 2008/0293207 A1 Nov. 27, 2008
Liu US 2009/0191705 A1 July 30, 2009
Nam US 2010/0065919 A1 Mar. 18,2010
The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows: claims 1,
4, 7, 8, 10, 13-16, 20-22, 25, 26, and 31-33 over Nam in view of Zhang and
2
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Application 13/074,888
Liu, claims 23, 24, and 30 over Nam in view of Zhang, and claims 5 and 11
over Nam in view of Zhang, Liu and Koutny.
OPINION
We reverse the rejections. We need address only the independent
claims (1, 8, 15, and 23).1 Those claims require a semiconductor device
wherein a volume of conductive fill material (276) in a first opening
measured at a cross-sectional area parallel to first width is substantially
constant from a bottom portion of a first insulating material (222) to the
bottom portion of a second insulating material (232) (Fig. 11).
Nam discloses a semiconductor device wherein a contact
hole (147a-c)’s contact plug (171, 173, 175) volume is constant from a
bottom portion of a first insulating film (140) to a top portion of a second
insulating film (142) (]fl| 83, 86; Fig. 1A).
Zhang discloses that “to form contacts with good coverage, it is
desired to have a continuously mildly changing cross-sectional shape, or a
tapering shape” (^ 16). Zhang forms a contact hole through a first interlayer
insulating film (114) having a relatively low etch rate below a second
interlayer insulating film (115) having a relatively high etch rate so the
contact hole’s tilt angle (a) in the first interlayer insulating film (114) is
greater than the contact hole’s tilt angle (|3) in the second interlayer
insulating film (115) such that the contact hole in the first insulating
film (114) has a conical shape sloping inwardly from top to bottom (]fl| 21,
67, 73; Figs. 2A, 3). The interlayer insulating films (114, 115) then are
1 The Examiner does not rely upon Koutny for any disclosure that remedies
the deficiency in the references applied to the independent claims as to the
limitations in those claims (Final Act. 19-20).
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Application 13/074,888
lightly etched to widen the contact hole, remove undercutting inside the
contact hole, eliminate overetched portions in a gate insulating film (103)
below the first interlayer insulating film (114), and taper the top portion of
the contact hole (]fl| 29, 31, 33, 78; Fig. 2C). The contact hole’s top portion
taper improves interconnect electrode coverage 34).
The Examiner asserts that Zhang’s contact hole’s tapered top portion
in a second insulating film (115) (Figs. 2A, 2D) could be combined with
Nam’s constant cross-sectional area contact hole (147a-c) in a first
insulating film (140) (Fig. 1A) (Ans. 4-5).
Establishing a prima facie case of obviousness of an invention
comprising a combination of known elements requires “an apparent reason
to combine the known elements in the fashion claimed.” KSR Int’l Co. v.
Teleflex Inc., 550 U.S. 398, 418 (2007).
The Examiner does not provide the required apparent reason why one
of ordinary skill in the art would have combined Nam and Zhang in the
manner proposed by the Examiner. Moreover, Zhang’s light etching which
provides the contact hole tapering at the upper portion of the second
insulating film (115) (Figs. 2A, 2D) is part of the process that tapers the
contact hole portion in the first insulating film (114) (]fl| 21, 28-34, 67, 73,
78). The Examiner does not establish that Zhang would have enabled one of
ordinary skill in the art to taper Nam’s contact hole’s portion at the top of the
second insulating film (142) without tapering the contact hole in the first
insulating film (140) such that the contact hole fails to meet the Appellants’
claim requirement that the contact hole’s cross-sectional area is substantially
constant from a bottom portion of a first insulating material (222) to the
bottom portion of a second insulating material (232) (Fig. 11).
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Application 13/074,888
Thus, the Examiner has not established a prima facie case of
obviousness of the Appellants’ claimed semiconductor device.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 1, 4, 7, 8, 10, 13-16,
20-22, 25, 26, and 31-33 over Nam in view of Zhang and Liu, claims 23,
24, and 30 over Nam in view of Zhang, and claims 5 and 11 over Nam in
view of Zhang, Liu and Koutny are reversed.
It is ordered that the Examiner’s decision is reversed.
REVERSED
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