Ex Parte Anderson et al

Patent Trial and Appeal Board

Jul 29, 2014

12035449 (P.T.A.B. Jul. 29, 2014)

UNITED STATES PATENT AND TRADEMARK OFFICE
__________

BEFORE THE PATENT TRIAL AND APPEAL BOARD
__________

Ex parte FELIX P. ANDERSON,
STEVEN P. BARKYOUMB, EDWARD C. COONEY III,
THOMAS L. McDEVITT, WILLIAM J. MURPHY,
and DAVID C. STRIPPE
__________

Appeal 2012-002208
Application 12/035,449
Technology Center 2800
___________

Before ADRIENE LEPIANE HANLON, CATHERINE Q. TIMM, and
JAMES C. HOUSEL, Administrative Patent Judges.

HANLON, Administrative Patent Judge.

DECISION ON APPEAL

A. STATEMENT OF THE CASE
Felix P. Anderson, et al. (“Appellants”) appeal under 35 U.S.C. § 134 from a
final rejection of claims 3-12, 14-21, and 23-28.1 We have jurisdiction under
35 U.S.C. § 6(b).
We AFFIRM-IN-PART and enter new grounds of rejection.

1 Claims 1 and 2 are also pending but have been withdrawn from consideration.
Final Office Action dated July 1, 2010 (“Final Act.”), at 1.
Appeal 2012-002208
Application 12/035,449

2

Claims 3 and 17 are illustrative of the subject matter on appeal and are
reproduced below from the Claims Appendix of the Appeal Brief dated December
1, 2010 (“App. Br.”). The limitations at issue are italicized.
3. A method of fabricating a semiconductor structure comprising
increasing a mol percent of nitride with respect to a total tantalum plus
nitride to 25% or greater during a barrier layer fabrication process,
wherein the mol percentage of the nitride is increased by
introducing nitrogen as a heat transfer medium between a wafer and
a chuck such that the nitrogen leaks from a back side of the wafer to a
surface of the wafer.
17. A method of fabricating a semiconductor structure comprising
adjusting a parameter in a chamber to increase a mol percent of nitride
to 25% or greater with respect to a total tantalum plus nitride during a
Pressure Vapor Deposition (PVD) process,
wherein the adjusting includes introducing nitrogen as a heat
transfer medium between a wafer and a chuck.
The claims on appeal stand rejected as follows: claims 3-6, 8-12, 14-18, 20,
21, and 23-27 under 35 U.S.C. § 103(a) as unpatentable over Nogami2 in view of
Ashtiani3; and claims 7, 19, and 28 under 35 U.S.C. § 103(a) as unpatentable over
Nogami in view of Ashtiani and further in view of Lage.4
B. DISCUSSION
1. Claim 3
The Examiner finds that Nogami discloses a method of fabricating a
semiconductor structure comprising increasing a mol percent of nitride to 25% or

2 US 6,117,769, issued September 12, 2000.
3 US 6,905,959 B1, issued June 14, 2005.
4 US 6,184,073 B1, issued February 6, 2001.
Appeal
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Appeal 2012-002208
Application 12/035,449

4

Although Nogami introduces nitrogen into chamber 200 during
semiconductor fabrication, the Examiner finds that Nogami does not disclose that
nitrogen is introduced as a heat transfer medium between a wafer and a chuck such
that the nitrogen leaks from a back side of the wafer to a surface of the wafer as
recited in claim 3. Ans. 3.
The Examiner finds that Ashtiani uses nitrogen gas to cool a cold
electrostatic chuck during a tantalum nitride barrier deposition.6 Ans. 3, 6;
Ashtiani, col. 8, ll. 29-36. The Examiner concludes that it would have been
obvious to one of ordinary skill in the art to cool chuck 204 of Nogami with
nitrogen gas to produce a cold tantalum nitride barrier as taught by Ashtiani. Ans.
3, 6-7. The Examiner finds that in the proposed combination, nitrogen gas would
leak from a back side of the wafer (202/300) to a surface of the wafer. Ans. 4.
The Appellants argue:
Nogami does not necessarily disclose that the nitrogen would leak
from a back side of the substrate 202 to the surface of the substrate
202 [as recited in claim 3]. Instead, the shield 208 would appear to
prevent the nitrogen from leaking from the back side of the substrate
202 to the surface of the substrate 202 . . . .
App. Br. 11.
Referring to Nogami Figure 2, the Examiner finds:
Since the shield ends below the back side of the wafer, the space
between the edges of the back side of the wafer and the front side of
the wafer is open to gas flow. Since the nitrogen gas is free to move
around in that particular space, and a gas molecules necessarily move

6 In the Final Office Action, the Examiner found that “Applicant Admitted Prior
Art shows that it is conventional to use an inert gas as a heat transfer medium
between an electrostatic chuck and a wafer (see par. 0026 of current application).”
Final Act. 3. Although this finding appears on pages 4, 7, and 9 of the Examiner’s
Answer, the Examiner indicated on page 2 of the Advisory Action dated October
15, 2010, that reliance on the “Applicant Admitted Prior Art” was withdrawn.
Appeal 2012-002208
Application 12/035,449

5

around in the volume they are allowed, the nitrogen gas will
necessarily move from the back side of the wafer to the surface of the
wafer (and vice versa).
Ans. 14; see also Ans. 11.
However, the Appellants argue:
Nogami does not disclose that the nitrogen gas is free to move around
the chamber 200 and can then leak from a back side of the silicon
substrate 202 to a surface of the silicon substrate 200. This is mere
conjecture on the part of the Examiner. . . . In addition, . . . nitrogen
gas moving freely about the chamber 200 is contrary to the teaching
of Nogami. In particular, Nogami describes the shield 208, which
blocks or prevents the nitrogen gas from moving freely about the
chamber 200, e.g., onto the interior walls 209. Accordingly, the
Examiner’s assertions are contrary to the teachings of Nogami.
Reply Br. 3.7
Nogami discloses that “shield 208 is positioned within the interior of the
chamber 200 to prevent target material from being deposited on the interior walls
209 of the chamber 200.” Nogami, col. 4, ll. 15-18. The Examiner has not
directed us to any evidence establishing that the nitrogen gas in Nogami’s method
will necessarily move from a back side of the wafer to a surface of the wafer as
recited in claim 3. See In re Oelrich, 666 F.2d 578, 581 (CCPA 1981) (quoting
Hansgirg v. Kemmer, 102 F.2d 212, 214 (CCPA 1939) (“Inherency . . . may not be
established by probabilities or possibilities.”).
Based on the foregoing, we find that a preponderance of the evidence of
record weighs against a conclusion of obviousness. Therefore, the § 103(a)
rejection of claims 3-6, 8-12, 14-16, and 27 is not sustained.
The Examiner does not rely on Lage to cure the deficiencies in Nogami.
Therefore, the § 103(a) rejection of claims 7 and 28 is not sustained.

7 Reply Brief dated August 2, 2011.
Appeal 2012-002208
Application 12/035,449

6

2. Claim 17
In contrast to claim 3, claim 17 does not recite that nitrogen leaks from a
back side of the wafer to a surface of the wafer. Claim 17 merely recites
“introducing nitrogen as a heat transfer medium between a wafer and a chuck.”
App. Br. 29 (emphasis added). Claim 17 does not require nitrogen to be
introduced between a wafer and a chuck or require heat to be transferred between a
wafer and a chuck. Thus, we interpret claim 17 as requiring that the nitrogen
introduced during the PVD process has the characteristics or functionality of a
medium that transfers heat between a wafer and a chuck, regardless of whether it
actually performs that function.
The Appellants disclose that a flow rate of nitrogen from between about 5
sccm to 100 sccm enables nitrogen to function as a heat transfer medium between a
wafer and a chuck. Spec. ¶¶ 36-37; see also Reply Br. 4. Nogami discloses that
the flow rate of nitrogen is from about 28 sccm to about 40 sccm, a range which is
completely encompassed by the range disclosed by the Appellants. Nogami, col.
6, ll. 37-38. Thus, we find that the nitrogen introduced into chamber 200 in
Nogami’s method has the characteristics of a heat transfer medium as recited in
claim 17. For this reason, the § 103(a) rejection of claim 17 is sustained.
The Appellants do not present separately distinct arguments in support of the
patentability of claims 18-21 and 23-25. See App. Br. 20, 24-25. Therefore, the
§ 103(a) rejections of claims 18-21 and 23-25 are also sustained.
3. Claim 26
Claim 25 depends from claim 17 and recites that “the adjusting includes
providing a negative voltage to a wafer.” App. Br. 30. Claim 26 depends from
claim 25 and recites that “the negative voltage is in a range of about -25V to -
200V.” App. Br. 30.
Appeal 2012-002208
Application 12/035,449

7

The Examiner finds, and the Appellants do not dispute, that Nogami
discloses that the mol percentage of the nitride is increased by providing a negative
charge to a wafer during a PVD process. Ans. 5, 8. The Examiner finds that
Nogami does not disclose that the negative voltage is in a range of about -25V to -
500V as recited in claim 26. Nonetheless, the Examiner concludes that the
particular voltage chosen would have been obvious based on “well known
manufacturing constraints and ascertainable by routine experimentation and
optimization.” Ans. 8.
The Appellants argue that page 12, line 15 to page 13, line 2 of the
Specification provides that the claimed voltage produces an unexpected result,
namely an increase in the mole percentage of nitrogen to tantalum. App. Br. 21.
However, the Specification does not characterize this increase as “unexpected.”
See In re Freeman, 474 F.2d 1318, 1324 (CCPA 1973) (in order for a showing of
“unexpected results” to be probative evidence of non-obviousness, the applicant
must establish that the difference between the results obtained through the claimed
invention and those of the prior art would not have been expected by one skilled in
the art at the time of invention); see also In re De Blauwe, 736 F.2d 699, 705 (Fed.
Cir. 1984) (unexpected results must be established by factual evidence; mere
argument does not suffice).
The § 103(a) rejection of claim 26 is sustained.
C. DECISION
The Examiner’s decision to reject claims 3-6, 8-12, 14-16, and 27 under
35 U.S.C. § 103(a) as unpatentable over Nogami in view of Ashtiani is reversed.
Appeal 2012-002208
Application 12/035,449

8

The Examiner’s decision to reject claims 7 and 28 under 35 U.S.C. § 103(a)
as unpatentable over Nogami in view of Ashtiani and further in view of Lage is
reversed.
The Examiner’s decision to reject claims 17, 18, 20, 21, and 23-26 under
35 U.S.C. § 103(a) as unpatentable over Nogami in view of Ashtiani is affirmed.
The Examiner’s decision to reject claim 19 under 35 U.S.C. § 103(a) as
unpatentable over Nogami in view of Ashtiani and further in view of Lage is
affirmed.
The portion of the opinion affirming the § 103(a) rejections of claims 17-21
and 23-26 relies on evidence and reasoning that was not relied on by the Examiner.
Therefore, we designate our affirmance a new ground of rejection under 37 C.F.R.
§ 41.50(b) which provides that “[a] new ground of rejection . . . shall not be
considered final for judicial review.”
37 C.F.R. § 41.50(b) also provides that the Appellants, WITHIN TWO
MONTHS FROM THE DATE OF THE DECISION, must exercise one of the
following two options with respect to the new grounds of rejection to avoid
termination of the appeal as to the rejected claims:
(1) Reopen prosecution. Submit an appropriate amendment of
the claims so rejected or new evidence relating to the claims so
rejected, or both, and have the matter reconsidered by the examiner, in
which event the proceeding will be remanded to the examiner. . . .
(2) Request rehearing. Request that the proceeding be reheard
under § 41.52 by the Board upon the same record. . . .

Appeal 2012-002208
Application 12/035,449

9

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-IN-PART
(37 C.F.R. § 41.50(b))

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