Ex Parte Kim et al

Patent Trial and Appeal Board

Oct 24, 2016

13462619 (P.T.A.B. Oct. 24, 2016)

UNITED STA TES p A TENT AND TRADEMARK OFFICE
APPLICATION NO. FILING DATE
13/462,619
90882 7590
LKGlobal (GF)
7010 E. Cochise Rd.
Scottsdale, AZ 85253
05/02/2012
10/26/2016
FIRST NAMED INVENTOR
Hoon Kim
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. CONFIRMATION NO.
089.0229 (DU019) 7728
EXAMINER
PATERSON, BRIGITTE A
ART UNIT PAPER NUMBER
2812
NOTIFICATION DATE DELIVERY MODE
10/26/2016 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@LKGlobal.com
PTOL-90A (Rev. 04/07)
UNITED STATES PATENT AND TRADEMARK OFFICE
BEFORE THE PATENT TRIAL AND APPEAL BOARD
Ex parte HOON KIM, and KISIK CHOI1
Appeal2015-005155
Application 13/462,619
Technology Center 2800
Before BRADLEY R. GARRIS, PETER F. KRATZ, and MICHAEL G.
McMANUS, Administrative Patent Judges.
GARRIS, Administrative Patent Judge.
DECISION ON APPEAL
Appellants appeal under 35 U.S.C. § 134 from the Examiner's
decision rejecting claims 1-8 and 16---22. We have jurisdiction under
35 U.S.C. § 6.
We AFFIRM.
1 Globalfoundries Inc. is identified as the real party in interest. App. Br. 1.
Appeal2015-005155
Application 13/462,619
Appellants claim a method of fabricating an integrated circuit
comprising: depositing a layer of a first barrier material 105 (Fig. 2);
depositing a layer of an n-type work function material 106 over the layer of
the first barrier material (Fig. 3); etching the layer of the first barrier material
and the layer of then-type work function material from a first area (Fig. 4);
depositing a layer of a second barrier material 107 (Fig. 5); and depositing a
layer of a p-type work function material 108 (Fig. 6) (independent claim 1;
see also remaining independent claims 16 and 21 ).
A copy of representative claim 1, taken from the Claims Appendix of
the Appeal Brief, appears below.
1. A method of fabricating an integrated circuit,
compnsmg:
depositing a layer of a first barrier material;
depositing a layer of an n-type workfunction material over the
layer of the first barrier material;
etching the layer of the first barrier material and the layer of the
n-type workfunction material from a first area;
depositing a layer of a second barrier material; and
depositing a layer of a p-type workfunction material.
Under 35 U.S.C. § 103(a), the Examiner rejects as unpatentable:
claim 1 over Kwon et al., (US 2012/0132998 Al, published May 31,
2012) ("Kwon") in view of Li et al., (US 2011/0215409 Al, published Sept.
8, 2011) ("Li"); and
remaining claims 2-8 and 16-22 over these references alone or in
combination with additional prior art.
Appellants do not present separate arguments specifically directed to
dependent claims 2-8, 17-20, and 22 (App. Br. 8-17). Therefore, these
dependent claims will stand or fall with their parent independent claims 1,
16, and 21. Because the arguments advanced against the rejection of claim 1
2
Appeal2015-005155
Application 13/462,619
(id. at 8-14) correspond to those concerning the rejections of claims 16 and
21 (id. at 16-17), claim 1 is representative of the independent claims.
We sustain the Examiner's rejections of the appealed claims for the
reasons expressed in the Final Action, the Answer, and below.
The Examiner finds that Kwon discloses a method of fabricating an
integrated circuit comprising (i) depositing layers of the claim 1 materials
including layer 38L of a second barrier material and (ii) etching from a first
area the n-type work function layer, albeit not the first barrier layer as
claimed (Final Action 2-3 (citing Kwan Figs. 10, 12, 13 and i-fi-162, 69, 73,
7 6) ). In this latter regard, the Examiner concludes that it would have been
obvious to etch the first barrier layer as well as the n-type work function
layer of Kwon in view of Li's teaching of etching first barrier as well as
work function layers in a first area during integrated circuit fabrication (id. at
3 (citing Li Figs. 4---6 and i-fi-147, 48, 52)).
Appellants argue the Examiner erred in finding that Kwon's layer 38L
.. ' ,.. • .. • .. .. "1 • "1 / .6. ~ l'"'\ A"\.') corresponas to tneir crn1mea secona oarr1er rnyer ~App. tir. <5-'J J.~
Specifically, Appellants point out that layer 38L is taught to be a second
work function material not the claimed second barrier material and argue
that, although both of these materials may be titanium nitride, Kwon's work
function material would not serve the purpose of a barrier material because
"titanium nitride, depending on how it is formed, may function either as a
barrier material (as in Appellants' invention) or as a work function material
(as in Kwon)" (id. at 8).
2 Appellants initially argued that the Examiner also erred in finding Kwon
discloses their claimed p-type workfunction layer (App. Br. 9) but have
expressly withdrawn this argument (Reply Br. 3).
3
Appeal2015-005155
Application 13/462,619
Appellants' argument is not persuasive. As the Examiner correctly
finds, Kwon's work function layer 38L comprises the same materials and
thicknesses as barrier layer 36L (Ans. 16 (citing Kwon i-fi-175-77 and 65---66
respectively). We emphasize that Appellants do not challenge this finding
by the Examiner in the record before us (see, e.g., the Reply Brief
generally). Therefore, the Examiner's finding is reasonably supported by
the circumstance wherein both of these layers comprise the same material
(e.g., titanium nitride) having the same thickness such that work function
layer 38L necessarily and inherently would possess the capability of
performing the barrier function of Appellants' claimed second barrier
material (e.g., titanium nitride (see Spec. i-f 19 and dependent claim 5)).
Appellants further contend that "the Office fails to provide any well-
founded reason or rationale why it would have been obvious to modify
Kwon with Li in the manner suggested in the Office Action" (App. Br. 11).
The Examiner explains that modifying Kwon by etching away the first
barrier layer (i.e., 36L) as well as then-type work function layer (i.e., 34L)
would have been suggested by Li's teaching of etching away both a first
barrier layer and a work function layer prior to depositing layers 28 and 29
of Li which correspond to layers 38L and 40L of Kwon (Ans. 17-18).
Appellants do not address this explanation with any reasonable specificity
and therefore do not show it to be erroneous (see Reply Br. 2--4). Based on
the record before us, the proposed modification of Kwon is nothing more
than the predictable use of a known etching technique for its established
function of preparing for the subsequent deposition of Kwon's layers 38L
and 40L as evidenced by Li.
4
Appeal2015-005155
Application 13/462,619
Finally, Appellants argue that, "[i]f the barrier material layer 36L in
Kwon were removed, then the subsequently-deposited second-type work
function material layer 38L (see FIG. 13, paragraphs [0074] - [0077]) would
be deposited directly on to the oxide gate dielectric layer 32L ... [which]
would result in a non-function[ al] device" (App. Br. 12). According to
Appellants, "the modification to Kwon suggested in the Office Action makes
[Kwon's] principal of operation not possible, namely the barrier material
layer 36L would be removed from region 25B, leaving only the second work
function material layer 38L in place" (id. at 13).
In response, the Examiner once again expresses the finding that layers
36L and 38L of Kwon comprise the same materials having overlapping
thicknesses (Ans. 19; see also id. at 16). For example, layer 36L may
comprise titanium nitride (Kwon i-f 65) having a thickness from 0.5-5 nm
(id. at i-f 66), and layer 38L may comprise titanium nitride (id. at i-f 76) having
a thickness from 2-100 nm (id. at i-f 77). As indicated previously, the
Examiner's finding is not challenged or otherwise addressed by Appellants
in their Reply Brief. For this reason, Appellants fail to provide the record
with any explanation why Kwon's device would be non-functional or the
principal of operation not possible if, for example, Kwon's envisioned
combination of a 1 nm layer 36L of titanium nitride and a 1 nm layer 38L of
titanium nitride on gate dielectric layer 32L were replaced with a 2 nm layer
38L of titanium nitride. Appellants' argument that the latter circumstance
would be non-functional or contrary to Kwon's principal of operation is not
convincing because, in either circumstance, the result would be a 2 nm thick
layer of titanium nitride on dielectric layer 32L.
5
Appeal2015-005155
Application 13/462,619
The decision of the Examiner is affirmed.
TIME PERIOD
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
6