Ex Parte Abe

Board of Patent Appeals and Interferences

Jan 15, 2009

10766739 (B.P.A.I. Jan. 15, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte KAZUHIDE ABE
____________

Appeal 2008-4986
Application 10/766,739
Technology Center 2800
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Decided: January 15, 2009
____________

Before TERRY J. OWENS, PETER F. KRATZ, and
ROMULO H. DELMENDO, Administrative Patent Judges.

OWENS, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE
The Appellant appeals under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 12-16 and 28-34, which are all of the pending claims.
We have jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellant claims a wiring structure of a semiconductor device.
Claims 12 and 28 are illustrative:
12. A wiring structure of a semiconductor device, comprising:

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a first insulating film having plural grooves formed therein, which has
an interface in a horizontal direction between adjoining grooves;

plural wiring films formed in the grooves of the first insulating film to
protrude above the interface;

plural barrier films formed on bottoms of the wiring films, and formed
on side faces of the wiring films to a height exceeding the interface; and

plural cap films formed at least on upper faces of the wiring films, and
which are each separated by the grooves,

wherein the first insulating film has plural protrusions protruding from
the interface, and the grooves are formed in the protrusions,

wherein the upper faces of the wiring films and the barrier films are
substantially coincident with upper ends of the grooves, and

wherein the protrusions are formed through etching the first insulating
film, using the cap films as a mask, and the cap films have substantially the
same shape as uppermost faces of the protrusions.

28. A wiring structure of a semiconductor device, comprising:

a first insulating film having plural protrusions in which grooves are
formed, and which has an interface in a horizontal direction between
adjoining protrusions;

plural wiring films embedded in the grooves on barrier films;

plural first cap films formed on upper faces of the protrusions; and

second cap films formed on the first cap films and the first insulating
film,

wherein the protrusions are formed through etching the first insulating
film, using the first cap films as a mask, and the cap films have substantially
the same shape as uppermost faces of the protrusions.
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The References
Higashi 6,342,444 B1 Jan. 29, 2002
Lim 6,380,084 B1 Apr. 30, 2002
Yu 6,958,291 B2 Oct. 25, 2005
(filed Sep. 4, 2003)

The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows:
claims 12-15 and 33 over Lim in view of Higashi, and claims 16, 28-32,
and 34 over Lim in view of Higashi and Yu.
OPINION
We affirm the Examiner’s rejections.
Rejection under 35 U.S.C. § 103 of claims
12-15 and 33 over Lim in view of Higashi

The Appellant argues claims 12-15 and 33 as a group (App. Br. 5-10;
Reply Br. 2). We therefore limit our discussion to one claim in that group,
i.e., claim 12. See 37 C.F.R. § 41.37(c)(1)(vii) (2007).
Issue
Has the Appellant shown reversible error in the Examiner’s
determination that the applied references, collectively, disclose each element
of claim 12?
Findings of Fact
Lim discloses “the formation of dual damascene copper interconnects
in the manufacture of integrated circuit devices” (col. 1, ll. 10-12). The
Examiner relies upon Lim’s second dielectric layer 72 (Fig. 14) as
corresponding to the Appellant’s first insulating film having plural grooves
(one of which is shown in a hillock in Lim’s Fig. 11) and, between adjoining
grooves, an interface in a horizontal direction (horizontal surface of second
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dielectric layer 72 on each side of the hillock) (col. 6, ll. 50-60) (Ans. 3).
The Examiner relies upon Lim’s second copper layers 84 (one of which is
shown in Fig. 14) as corresponding to the Appellant’s plural wiring films
formed in the grooves of the first insulating film to protrude above the
interface (col. 7, l. 56 – col. 8, l. 19) (Ans. 3). The Examiner relies upon
Lim’s shielding layer 56 and third barrier layer 80 as corresponding to the
Appellant’s plural barrier films formed on bottoms of the wiring films, and
formed on side faces of the wiring films to a height exceeding the interface
(Fig. 14) (col. 5, ll. 13-27; col. 7, ll. 28-39) (Ans. 3). The upper faces of
Lim’s wiring films and barrier films are flat and are substantially coincident
with upper ends of the grooves, which are stripe-shaped (Fig. 14). The
Examiner relies upon Lim’s hillocks (one of which is shown in Fig. 14) as
corresponding to the Appellant’s plural protrusions protruding from the first
insulating film’s interface and having the grooves therein (Ans. 3).
Higashi discloses a semiconductor device comprising an insulating
film (1) having a groove therein (Fig. 1G), a TiN barrier layer (5) on the
bottom and sides of the groove and protruding above the insulating film
surface, a copper layer (6) that fills the space within the barrier layer and has
an upper surface coincident with that of the barrier layer (Fig. 1G), and a
self-aligned TiN barrier layer (9) on the upper surfaces of the copper layer
and the barrier layer (col. 4, ll. 20-24, 43-45, 57-58). Higashi teaches that
the semiconductor device has “reduced wiring capacitance and wiring
resistance, and the [sic] good barrier and uniformity properties” (col. 2, ll.
13-15).
Yu discloses a semiconductor device comprising a dielectric
layer (120) having therein a groove containing a barrier layer (140) and,
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filling the space within the barrier layer, a conductor (160), wherein the
barrier layer and the conductor protrude above the upper surface of the
dielectric layer and have coincident upper faces (col. 5, ll. 23-29; Fig. 7). In
one Yu embodiment a passivation layer (170) overlies the conductor and the
dielectric layer (col. 5, ll. 25-27). In another Yu embodiment “a conductive
passivation layer (not shown) can be formed only overlying the second
conductor as a capping layer” (col. 5, ll. 33-35). Yu’s conductive
passivation layer (not shown) preferably is self aligned (col. 5, ll. 35-36).
Analysis
The Appellant argues that Higashi’s cap film (TiN layer 9) is formed
only on copper layer 6, whereas the Appellant’s cap films are formed at least
on the upper faces of the wiring films, not only on the wiring films (App.
Br. 8).
The Appellant’s claim limitation “formed at least on upper faces of
the wiring films” encompasses formation only on the upper faces of the
wiring films. Moreover, Higashi’s TiN layer 9 actually is formed not only
on copper layer 6, but also on the upper surface of TiN layer 5 (Fig. 1G).
The Appellant argues that Higashi’s TiN layer 9 would not extend
onto the hillock of Lim’s second dielectric layer 72 immediately surrounding
second copper layer 84/third barrier layer 80 (App. Br. 8).
The Appellant’s claim 12 requires that the cap films are formed at
least on upper faces of the wiring films. The claim does not require that the
cap films extend onto the insulating film surface.
The Appellant argues that Higashi’s TiN layer 9 could not possibly
have substantially the same shape as uppermost faces of the hillock and, if
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anything, would have substantially the same shape as the uppermost face of
the wiring (App. Br. 8-9; Reply Br. 2).
The Appellant’s claim 12 requires that the cap films have substantially
the same shape as uppermost faces of the protrusions, not the insulating film.
Higashi’s TiN layer 9 would have substantially the same shape as the
uppermost faces of the protrusions formed by Lim’s hillock, third barrier
layer 80 and second copper layer 84, i.e., flat and stripe shaped (Lim,
Fig. 14).
Conclusion of Law
The Appellant has not shown reversible error in the Examiner’s
determination that the applied references, collectively, disclose each element
of claim 12.
Rejection under 35 U.S.C. § 103 of claims 16, 28-32,
and 34 over Lim in view of Higashi and Yu

The Appellants argue claims 16, 28-32, and 34 as a group (App. Br.
10-14; Reply Br. 3-5). We therefore limit our discussion to one claim in that
group, i.e., claim 28. See 37 C.F.R. § 41.37(c)(1)(vii) (2007).
Issue
Has the Appellant shown reversible error in the Examiner’s
determination that the applied references would have rendered the invention
claimed in the Appellant’s claim 28 prima facie obvious to one of ordinary
skill in the art?
Analysis
The Appellant relies upon the above-discussed arguments set forth
with respect to claim 12 (App. Br. 10-13; Reply Br. 3-4).
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For the reasons given above regarding claim 12, we are not persuaded
by those arguments.
The Appellant argues that Yu’s conductive passivation layer (not
shown) appears to be similar to Higashi’s TiN layer 9, and is formed only on
the wiring, not on the wiring and the insulating film (App. Br. 13-14; Reply
Br. 4-5).
The Appellant’s claim 28 requires “plural first cap films formed on
upper faces of the protrusions”. That claim limitation is met by Higashi’s
TiN layer 9 (col. 4, ll. 44-46, 57-58) or Yu’s self-aligned conductive
passivation layer (not shown) (col. 5, ll. 33-35).
The Appellant’s claim 28 also requires second cap films formed on
the first cap films and the first insulating film. Yu’s passivation layer 170 is
formed on both conductor 160 and dielectric layer 120 (col. 5, ll. 23-29;
Fig. 7). Yu would have led one of ordinary skill in the art, through no more
than ordinary creativity, to apply Yu’s passivation layer over Yu’s self-
aligned conductive passivation layer or Higashi’s self-aligned TiN barrier
layer 9 and the insulating layer surrounding them to provide passivation of
those layers. See KSR Int’l. Co. v. Teleflex Inc., 127 S. Ct. 1727, 1741
(2007) (In making an obviousness determination one “can take account of
the inferences and creative steps that a person of ordinary skill in the art
would employ”). See also KSR, 127 S. Ct. at 1740 (“[I]f a technique has
been used to improve one device, and a person of ordinary skill in the art
would recognize that it would improve similar devices in the same way,
using the technique is obvious unless its actual application is beyond his or
her skill”).

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Conclusion of Law
The Appellant has not shown reversible error in the Examiner’s
determination that the applied references would have rendered the invention
claimed in the Appellant’s claim 28 prima facie obvious to one of ordinary
skill in the art.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 12-15 and 33 over
Lim in view of Higashi, and claims 16, 28-32, and 34 over Lim in view of
Higashi and Yu are affirmed.
It is ordered that the Examiner’s decision 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).
AFFIRMED

PL Initial:
sld

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