Ex Parte Ivanov

Board of Patent Appeals and Interferences

Apr 27, 2012

11199620 (B.P.A.I. Apr. 27, 2012)

UNITED STATES PATENT AND TRADEMARKOFFICE
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.
11/199,620 08/09/2005 Igor C. Ivanov 5866-01701 2752
35617 7590 04/27/2012
DAFFER MCDANIEL LLP
P.O. BOX 684908
AUSTIN, TX 78768
EXAMINER
HORNING, JOEL G
ART UNIT PAPER NUMBER
1712
MAIL DATE DELIVERY MODE
04/27/2012 PAPER
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.
PTOL-90A (Rev. 04/07)

UNITED STATES PATENT AND TRADEMARK OFFICE
_________________

BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_________________

Ex parte IGOR C. IVANOV

_________________

Appeal 2010-010657
Application 11/199,620
Technology Center 1700
_________________

Before CATHERINE Q. TIMM, KAREN M. HASTINGS, and
DEBORAH KATZ, Administrative Patent Judges.

KATZ, Administrative Patent Judge.

DECISION ON APPEAL

Appeal 2010-010657
Application 11/199,620

2
Appellants1 seek our review, under 35 U.S.C. § 134(a), of the
Examiner’s decision to reject claims 1, 2, 4-7, 12-16, and 44-47. (App. Br.
2.) Appellants report that claims 17-43 have been cancelled and claims 3
and 8-11 have been withdrawn. (Id.) We have jurisdiction under 35 U.S.C.
§ 6(b). We affirm.
The Examiner rejected claims 1, 2, 4-7, 12, 14, 15, 45-46, and 47
under 35 U.S.C. § 103(a) over Dubin2 and Danek.3 (Ans. 4-8.) Appellants
present the same arguments against the rejection of independent claims 1
and 14 and do not argue for the separate patentability of the claims
dependent on them. (See App. Br. 5 and 20.) We focus on claim 1 in our
review. See 37 C.F.R. § 41.37(c)(1)(vii).
Appellants’ claim 1 is directed to a microelectronic topography that
includes a diffusion barrier, which inhibits metal features from diffusing to
underlying or overlaying layers of the topography deposited. (Id. at 2.)
Appellants’ claim 1 recites:
A microelectronic topography, comprising:

a metal structure having a bulk concentration of a first
element disposed throughout the metal structure; and

a diffusion barrier film formed in contact with the metal
structure, wherein the diffusion barrier film is substantially
absent of the first element and comprises a plurality of distinct
metallic elements each different than the first element, wherein
the diffusion barrier film has periodic successions of regions,

1 The real party in interest is said to be Lam Research Corp. (App. Br. 1.)
2 Dubin et al., U.S. Patent 5,695,810, issued December 9, 1997.
3 Danek and Levy, U.S. Patent 5,942,799, issued August 24, 1999.
Appeal 2010-010657
Application 11/199,620

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and wherein each of the periodic successions of regions
comprises:

at least one region with a concentration of a second
element greater than a set amount, wherein the second element
is one of the plurality of metallic elements of the diffusion
barrier film; and

at least one region with a concentration of the second
element less than the set amount.

(App. Br. 23, Claims App’x.)
Appellants’ arguments raise the issue of whether those of ordinary
skill in the art would have combined the teachings of Dubin and Danek.
Specifically, Appellants argue that any modification of the barrier taught in
Dubin by the teachings of Danek would create a multi-layer diffusion barrier
of cobalt-tungsten-phosphorus (“CoWP”) with layers thinner than those
taught in Dubin and that such thinner films of CoWP would not meet the
requirements for the multilayer structure of Danek. (App. Br. 5.)
According to Appellants, Dubin teaches a diffusion barrier with a
single CoWP layer that is 150-200 nm thick, while Danek teaches a
multilayer barrier with ultrathin layers of 10-50 angstroms. (App. Br. 6,
citing Dubin, col. 6, ll. 20-23, and Danek, col. 2, ll. 28-35, col. 4, ll. 58-61,
col. 5, ll. 46-49, and col. 6, ll. 21-24.) Appellants argue that these teachings
would have prompted those of skill in the art to have formed a multilayer
structure with sub-layers of 100-200 nm or greater, contrary to the interest in
the art of reducing microelectronic topographies. (App. Br. 7-8.)
Appeal 2010-010657
Application 11/199,620

4
Appellants read Dubin and Danek too narrowly. As the Examiner
finds, although Danek provides certain examples of thicknesses of the
sublayers as being between 10 and 50 angstroms, Danek also teaches that
multilayer barriers can be engineered by selecting the compositions and
thicknesses of barrier sublayers that are most advantageous. (Danek, col. 6,
ll. 60-66; see Ans. 11.) Similarly, Dubin provides an example of a barrier of
150-200 nm, but also teaches that the specific details of the structures
described are not absolutely necessary to making diffusion barriers. (Dubin,
col. 3, l. 64, through col, 4, l. 3; see Ans. 11-12.)
Appellants acknowledge that those of skill in the art would not
necessarily be restricted to the thickness of layers taught in Danek and
Dubin, but argue that the relative degree of thickness would be taken into
account to create a multi-layer structure. (Reply. Br. 5.) We are not
persuaded that the layers of different thicknesses exemplified in Dubin and
Danek fail to suggest to the ordinary artisan the creation of the diffusion
barrier of Appellants’ claimed microelectronic topography.
The test for obviousness is not whether the features of a
secondary reference may be bodily incorporated into the
structure of the primary reference; nor is it that the claimed
invention must be expressly suggested in any one or all of the
references. Rather, the test is what the combined teachings of
the references would have suggested to those of ordinary skill
in the art.

In re Keller, 642 F.2d 413, 425 (C.C.P.A. 1981). The regions of Appellants’
claimed diffusion barrier film are not restricted to specific thicknesses.
Thus, we are not persuaded that any particular thickness is excluded from
Appellants’ claimed topography. Danek teaches that multiple layer barriers
Appeal 2010-010657
Application 11/199,620

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have the advantage of superior diffusion barrier reliability due to
suppression of grain boundary diffusion by the periodic structure. (See
Danek, col. 2, l. 64, through col. 3, l. 3; Ans. 5).) Appellants’ argument that
those in the art were continually seeking to reduce microelectronic
topographies does not persuade us that those in the art would have been
dissuaded from forming a diffusion barrier such as in Dubin with multiple
layers. Even if the layers of Danek are thinner than what is discussed in
Dubin, it would appear that the advantage of suppressing grain boundary
diffusion by using the multilayer structure of Danek would be obtained.
Appellants have not provided sufficient evidence to persuade us that the
multiple layers taught in Danek would be incompatible with the diffusion
barrier of Dubin.4
Accordingly, the preponderance of the evidence supports the
Examiner’s conclusion that it would have been obvious to have used the
multilayers of Danek in the barrier of Dubin.

4 Appellants cite two research articles Chang and Lu, “Thermal Stability and
Interface Diffusion Behaviors of Electrolessly Deposited CoWP and Cu
Films,” 155 J. Electrochemical Soc’y D234 (2008) and Tsai, et al.,
“Electroless CoWP as a Diffusion Barrier Between Electroless Copper and
Silicon,” 36 J. Electronic Materials 1408 (2007), as evidence that those of
skill in the art did not know the thermodynamic and kinetic stability of the
interfaces between layers of CoWP and copper at the time the claimed
subject matter was conceived. (App. Br. 12-13.) Even if these articles
demonstrate the state of the art, the articles do not persuade us that it was
expected that the multilayers of Danek would have been incompatible with
the barrier of Dubin.
.
Appeal 2010-010657
Application 11/199,620

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The Examiner also rejected dependent claims 13 and 16 under 35
U.S.C. § 103(a) over Dubin in view of Danek and Shacham-Diamond.5
(Ans. 8-9.) Claim 13 recites the microelectronic topography of claim 1,
“wherein the plurality of metallic elements comprise cobalt, molybdenum,
and at least one of chromium or boron.” (App. Br. 24, Claims App’x.)
Appellants argue that though Shacham-Diamond teaches films of
Co(MO,P), they are relatively thin and, according to Appellants, were not
known to be suitable for the multilayer diffusion barrier layer of Danek.
(See App. Br. 21.) For the reasons stated above, we are not persuaded that
the thickness of the films in Shacham-Diamond indicates there would not
have been a suggestion to use Co(Mo,P) in the diffusion barrier of Dubin.
Appellants have not directed us to sufficient evidence that those of skill in
the art would have considered the material of Shacham-Diamond to have
been incompatible with a barrier of Dubin having multiple layers.
The Examiner rejected dependent claim 44 over Dubin in view of
Danek and Chopra6 (id. 9-10). Appellants rely on their arguments against
the rejection of claim 1 over Dubin and Danek (see App. Br. 21), which we
find unpersuasive, as discussed above.

5 Shacham-Diamon et al., “Electroless Co(MO,P) films for Cu interconnect
application,” 64 Microelectronic Eng’g 315 (2002).
6 Chopra, U.S. Patent Application Publication 2002/0030274, published
March 14, 2002.
Appeal 2010-010657
Application 11/199,620

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Decision
Upon consideration of the record and for the reasons given, the
rejections of claims is sustained.
No time period for taking any subsequent action in connection with
this appeal may be extended under 37 C.F.R. § 1.136.

AFFIRMED
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