Ex Parte Andricacos et al

Board of Patent Appeals and Interferences

Mar 28, 2008

10309123 (B.P.A.I. Mar. 28, 2008)

UNITED STATES PATENT AND TRADEMARK OFFICE
____________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
____________

Ex parte PANAYOTIS ANDRICACOS,
STEVEN H. BOETTCHER, SANDRA G. MALHOTRA,
MILAN PAUNOVIC, and CRAIG RANSOM
____________

Appeal 2008-0082
Application 10/309,123
Technology Center 2800
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Decided: March 28, 2008
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Before CHARLES F. WARREN, PETER F. KRATZ, and
JEFFREY T. SMITH, Administrative Patent Judges.

KRATZ, Administrative Patent Judge.

DECISION ON APPEAL
This is a decision on an appeal from the Examiner’s final rejection of
claims 1-7, 9-12, 29, and 30. We have jurisdiction pursuant to 35 U.S.C. § 6.
Appellants’ invention is directed to an electronic structure including a
substrate dielectric layer having a via opening that includes an underlayer on
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Application 10/309,123

the via sidewall and bottom surfaces with a barrier layer located on the
underlayer. The underlayer includes cobalt, nickel and/or a mixture thereof.
The barrier layer includes an alloy including cobalt and/or nickel, and
tungsten. The alloy includes 15-20 atomic percent of tungsten. Claim 1 is
illustrative and reproduced below:
1. An electronic structure comprising:

a substrate having a dielectric layer having a via opening
therein; the via opening have an underlayer of cobalt, nickel or
both deposited on sidewalls and bottom surfaces of the via
opening; and

a barrier layer on the underlayer on the sidewalls and
bottom surfaces of the underlayer; wherein the barrier layer
comprises an electrodeposited layer of an alloy comprising at
least one member selected from the group consisting of cobalt,
nickel and mixtures thereof, and tungsten; wherein the alloy
comprises about 15 atomic percent to about 20 atomic percent
of tungsten.

The Examiner relies on the following prior art references as evidence
in rejecting the appealed claims:
Bengston 5,235,139 Aug. 10, 1993
Lopatin (Lopatin ‘096) 6,144,096 Nov. 7, 2000
Nakano 2001/0030366 A1 Oct. 18, 2001
Ueno 2004/0126548 A1 Jul. 1, 2004

S. Lopatin & Y. Shacham-Diamand (Lopatin I), Electrochemical Society
Proceedings, Vol. 97-8 (1997) 186-195.

Claims 1-3, 6, 7, 9, 10, 12, and 29 stand rejected under 35 U.S.C. §
103(a) as being unpatentable over Lopatin ‘096 in view of Nakano. Claim 4
stands rejected under 35 U.S.C. § 103(a) as being unpatentable over Lopatin
‘096 in view of Nakano, and Lopatin I. Claim 5 stands rejected under 35
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U.S.C. § 103(a) as being unpatentable over Lopatin ‘096 in view of Nakano
and Bengston. Claim 11 stands rejected under 35 U.S.C. § 103(a) as being
unpatentable over Lopatin ‘096 in view of Nakano and Ueno. Claim 1
stands rejected under 35 U.S.C. § 103(a) as being unpatentable over Ueno.1
We affirm all of the above-maintained rejections for substantially the
reasons and factual findings set forth by the Examiner in the Answer and as
further discussed below.
We begin with the Examiner’s obviousness rejection of claims 1-3, 6,
7, 9, 10, 12, and 29. These commonly rejected claims are argued together as
a group. Hence, we select claim 1 as the representative claim on which we
decide this appeal as to this grounds of rejection.
Under 35 U.S.C. § 103, the factual inquiry into obviousness requires a
determination of: (1) the scope and content of the prior art; (2) the
differences between the claimed subject matter and the prior art; (3) the level
of ordinary skill in the art; and (4) any secondary considerations (e.g., the
problem solved). Graham v. John Deere Co., 383 U.S. 1, 17-18 (1966).
“[A]nalysis [of whether the subject matter of a claim is obvious] need not
seek out precise teachings directed to the specific subject matter of the
challenged claim, for a court can take account of the inferences and creative
steps that a person of ordinary skill in the art would employ.” KSR Int’l Co.
Teleflex, Inc., 127 S. Ct. 1727, 1740-41 (2007), quoting In re Kahn, 441
F.3d 977, 988 (Fed. Cir. 2006); see also DyStar Textilfarben GmbH & Co.
Deutschland KG v. C.H. Patrick Co., 464 F.3d 1356, 1361 (Fed. Cir. 2006)

1 The Examiner has withdrawn a rejection of claims 1-3, 12, and 29 under
35 U.S.C. § 102(e) as being anticipated by Ueno (Ans. 10). Accordingly,
this anticipation rejection is not before us for review.
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(“The motivation need not be found in the references sought to be combined,
but may be found in any number of sources, including common knowledge,
the prior art as a whole, or the nature of the problem itself.”); In re Bozek,
416 F.2d 1385, 1390 (CCPA 1969) (“Having established that this knowledge
was in the art, the examiner could then properly rely, as put forth by the
solicitor, on a conclusion of obviousness ‘from common knowledge and
common sense of the person of ordinary skill in the art without any specific
hint or suggestion in a particular reference.’”).
Appellants do not contest that Lopatin ‘096 discloses or suggests an
electronic structure including a substrate dielectric layer, with a via having
sidewall and bottom surfaces covered by an underlayer, then a tungsten-
containing barrier layer, as called for in representative claim 1, but for the
claim requirement for about 15-20 atomic percent of tungsten in the barrier
layer (Br. 10; Reply Br. 7-8; Ans. 6).2 In this regard, Lopatin ‘096 discloses
or suggests that a barrier layer (204, Fig. 4), which can comprise a mixture
of Group VIII B element (for example, cobalt or nickel) with a Group VI B
element (for example, tungsten), is deposited on an adhesion layer
(underlayer) (208, Fig. 4), which underlayer includes a Group VIII B metal
element (col. 4, ll. 18-19, col. 4, l. 49- col. 5, l. 40). Lopatin ‘096 further
discloses that cobalt tungsten (CoW) and nickel tungsten (NiW) are
preferred combinations for the barrier layer (col. 4, ll. 58-65).
Lopatin ‘096 discloses that an optimal amount of the Group VI B
element is from about 0.2 weight percent to about 4 weight percent of the
Group VIII B element (col. 5, ll. 5-8), which represents a smaller amount of

2 Arguments not made in the Briefs are considered to be waived. See 37
C.F.R. § 41.37(c)(vii) (2006).
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tungsten than called for in representative claim 1. However, Lopatin ‘096
further suggests that the varying proportion of Group V B or Group VI B
material (tungsten) employed in the barrier layer can have different degrees
of effect. Id. In other words, the relative amount of tungsten utilized in the
barrier layer would have been recognized as a result effective parameter by
one of ordinary skill in the art based on the disclosure of Lopatin ‘096.
Moreover, the Examiner further relies on the teachings of Nakano with
regard to the prior art use of 20 atomic weight percent tungsten in a cobalt
alloy used as a barrier layer for a semiconductor device (¶ 0071). Based on
the combined teachings of Lopatin ‘096 and Nakano, we agree with the
Examiner that the applied prior art evidence establishes a prima facie case of
obviousness for the claimed subject matter. The applied references
reasonably suggest that one of ordinary skill in the art would have been led
to employ an amount of tungsten in the barrier layer, such as the barrier
layer of Lopatin ‘096, which amount falls within the claim 1 scope of about
15-20 atomic weight percent of tungsten based on the combined teachings of
the applied references. Determining an amount of tungsten for the barrier
layer corresponding to the here-claimed amount would have reasonably been
expected to be arrived at by an ordinarily skilled artisan upon routine
experimentation for purposes of determining the workable or operable
amounts of tungsten that can be used in the barrier layer.
Appellants contend that there is a lack of suggestion or motivation for
one of ordinary skill in the art to employ the barrier material alloy of Nagano
comprising 20 atomic percent tungsten as the barrier material in Lopatin
‘096. In Appellants’ opinion, this is so because Nagano employs a different
underlayer than used by Lopatin ‘096 and Nagano is not limited to only
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using 20 atomic percent tungsten barrier material alloy materials (Br. 10,
Reply Br.7-8). Moreover, Appellants point to another U.S. Patent of record
(Nogami, U.S. Pat. No. 6,010,960) in urging that the fact that barrier
material including an amount of tungsten, as claimed, was known prior in
time to Lopatin ‘096 establishes a lack of motivation to employ such a
barrier material having this higher relative amount of tungsten as the barrier
layer of Lopatin ‘096 (Reply Br. 8). As best understood, this argument is
premised on the notion that Lopatin ‘096 did not furnish a description or
suggestion of using such known materials containing higher tungsten
amounts therein.
Of course, it is manifest that an anticipatory disclosure is not required
to make out a prima facie case of obviousness. Moreover, the arguments
presented and the additional evidence relied upon in support thereof are not
persuasive of reversible error in the Examiner’s obviousness rejection of
representative claim 1. Like Appellants, both Lopatin ‘096 and Nakano are
concerned with furnishing a barrier layer for copper interconnects
(Specification 1-2; Lopatin ‘096, col. 2, ll. 8-54 and col. 5, l. 41; Nakano, ¶¶
0013, 0015, 0117, Table 5). In this regard, it is our view that one of ordinary
skill in the art would have been led to select known barrier materials for
copper interconnects, such as taught by Nakano, as a material for use in the
barrier material layer of Lopatin ‘096 with a reasonable expectation of
success in so doing. As the Examiner has pointed out, that the rejection is
based on the combined teachings of the applied references, not each applied
reference as if applied alone (Ans. 12). After all, in considering the question
of the obviousness of the claimed invention in view of the prior art relied
upon, we are further guided by the basic principle that the question under 35
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U.S.C. § 103 is not merely what the references expressly teach but what they
would have suggested, in combination, to one of ordinary skill in the art at
the time the invention was made. See Merck & Co. v. Biocraft Labs., Inc.,
874 F.2d 804, 807 (Fed. Cir. 1989) and In re Keller, 642 F.2d 413, 425
(CCPA 1981). Moreover, the question of obviousness cannot be approached
on the basis that an artisan having ordinary skill would have known only
what they read in the references, because such artisan is presumed to know
something about the art apart from what the references disclose. See In re
Jacoby, 309 F.2d 513, 516 (CCPA 1962). Nor is it necessary that
suggestion or motivation be found within the four corners of the references
themselves.
As for the argued Nogami reference (U.S. Patent No. 6,010,960),
Appellants have not satisfactorily explained how this additional cited
reference, which also discloses the use of cobalt/tungsten barrier layers for a
copper interconnect, supports Appellants’ assertion respecting a lack of
motivation to use known cobalt/tungsten barrier materials, such as taught by
Nakano, as the barrier material for the barrier layer of Lopatin ‘096 (Reply
Br. 8).
Upon reconsideration in light of all of the evidence and arguments of
record that have been brought to bear on the question of obviousness before
us, we determine that the evidence of record, on balance, weighs in favor of
a determination of the obviousness of the representative claim 1 subject
matter.
As for the separate rejections of dependent claims 4, 5, and 11, each
involving additional prior art evidence as relied upon by the Examiner in
these separately presented rejections, we note that Appellants only argument
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with respect to the latter rejections is based on their arguments for the
patentability of independent claim 1. However, the arguments concerning
appealed claim 1 are not found persuasive of reversible error in the
Examiner’s rejection of claim 1, as explained above. It follows that, on this
record, we shall also affirm the Examiner’s separate obviousness rejections
of dependent claims 4, 5, and 11.
Lastly, the Examiner has presented another obviousness rejection of
claim 1 over the teachings of Ueno. Appellants do not contest the
Examiner’s determination that Ueno teaches or suggests an electrical device
in accordance with the required features of claim 1 including a nickel or
cobalt/tungsten barrier layer with amounts of tungsten corresponding to the
claimed amounts but for the claimed underlayer requirements (Ans. 9-10;
Br. 8-9; Reply Br. 8-9). In particular, Appellants argue against the propriety
of this last presented rejection principally on the contention that Ueno would
not have suggested or furnished a reasonable expectation of success for an
underlayer of nickel and/or cobalt being used with the cobalt/tungsten
barrier layer of Ueno.
This line of argument against the Examiner’s obviousness rejection
over Ueno is not persuasive of reversible error in the Examiner’s
obviousness rejection of claim 1 over Ueno for reasons set forth by the
Examiner in the Answer (Ans. 9, 10, 14 and 15). As explained by the
Examiner, Ueno does disclose the prior art use of cobalt (Co) adhesion or
underlayer when using a tungsten-containing barrier layer (Ans. 15; Ueno, ¶
0033). While Ueno indicates a preference for an organic silane
monomolecular adhesion layer when employing a tungsten-containing
barrier layer having amounts of tungsten corresponding to the here-claimed
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amounts, we agree with the Examiner that one of ordinary skill would have
recognized that the high tungsten content barrier layer could also be
employed with the disclosed prior art cobalt underlayer (adhesion layer).
This is so because Ueno merely indicates a preference, not a requirement,
for the monomolecular organic silane underlayer (adhesion layer) when
employing the use of a high tungsten-content barrier layer (Ueno, ¶ 0038).
All disclosure in reference must be evaluated for what it fairly
teaches, not just the preferred embodiments. In re Kaslow, 707 F.2d 1366,
1373 (Fed. Cir. 1983); In re Fracalossi, 681 F.2d 792, 793-794 (CCPA
1982); In re Lamberti, 545 F.2d 747, 750 (CCPA 1976).
On this record, we affirm the Examiner’s obviousness rejection of
claim 1 over Ueno.
CONCLUSION
The decision of the Examiner to reject claims 1-3, 6, 7, 9, 10, 12, and
29 under 35 U.S.C. § 103(a) as being unpatentable over Lopatin ‘096 in
view of Nakano; to reject claim 4 under 35 U.S.C. § 103(a) as being
unpatentable over Lopatin ‘096 in view of Nakano, and Lopatin I; to reject
claim 5 under 35 U.S.C. § 103(a) as being unpatentable over Lopatin ‘096 in
view of Nakano and Bengston; to reject claim 11 under 35 U.S.C. § 103(a)
as being unpatentable over Lopatin ‘096 in view of Nakano and Ueno; and
to reject claim 1 under 35 U.S.C. § 103(a) as being unpatentable over Ueno
is affirmed.

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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)(iv) (2006).

AFFIRMED

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