Ex Parte Fryer et al

Patent Trial and Appeal Board

Jun 18, 2013

11441767 (P.T.A.B. Jun. 18, 2013)

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.
11/441,767 05/26/2006 David Fryer ITL.1370US (P23260) 1872
21906 7590 06/18/2013
TROP, PRUNER & HU, P.C.
1616 S. VOSS ROAD, SUITE 750
HOUSTON, TX 77057-2631
EXAMINER
CHU, JOHN S Y
ART UNIT PAPER NUMBER
1722
MAIL DATE DELIVERY MODE
06/18/2013 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 PATENT TRIAL AND APPEAL BOARD
____________

Ex parte DAVID FRYER, VIVEK SINGH,
NIKOLAY SUETIN, and ALEX A. GRANOVSKY
____________

Appeal 2012-003422
Application 11/441,767
Technology Center 1700
____________

Before BRADLEY R. GARRIS, LINDA M. GAUDETTE, and DONNA M.
PRAISS, Administrative Patent Judges.

GAUDETTE, Administrative Patent Judge.

DECISION ON APPEAL

Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s decision1
finally rejecting claims 1, 5-8, 10, 13, and 14 under 35 U.S.C. §102(b) as
anticipated by or, in the alternative, under 35 U.S.C. §103(a) as unpatentable over
Yamatsu (US 6,048,669, issued Apr. 11, 2000) or Hanrahan (US 5,360,698, issued
Nov. 1, 1994), and claims 1, 4-8, 10, and 12-14 under 35 U.S.C. §103(a) as

1Final Office Action mailed Oct. 14, 2010
Appeal 2012-003422
Application 11/441,767

2
unpatentable over Yamatsu or Hanrahan in view of Ohsawa (US 6,838,224 B2,
issued Jan. 4, 2005).2 We have jurisdiction under 35 U.S.C. § 6(b).
We REVERSE.
The invention is directed to an improved method of manufacturing
semiconductor wafers. (See Spec.3 2:11-14.) At the time of the invention, it was
known in the art to use photoacid generators (PAGs) to degrade the photoresist
during exposure. (Id. at 2:3-5.) Appellants’ invention is directed toward
improving the efficiency of PAGs by increasing the number of acid molecules
generated per photon of resist exposure, thereby increasing the rate of degradation
of the photoresist. (Id. at 14-18.)
Appealed claim 1 is representative of the invention and is reproduced below
from the Claims Appendix to the Appeal Brief:
1. A method comprising:
forming more than one acid in a photoresist per absorbed photon; and
heating the photoresist to a temperature less than about 25°C below the glass
transition temperature of the photoresist while exposing it to radiation.

Appellants’ arguments in support of patentability raise the following issue:
did the Examiner reversibly err in finding the method of Yamatsu or Hanrahan,
alone or in view of Ohsawa, necessarily or inherently includes a step of “forming
more than one acid in a photoresist per absorbed photon”4 as required by the
appealed claims? (See Br. 9-10.)

2 Appeal Brief filed May 11, 2011 (“Br.”)
3 Specification filed May 26, 2006.
4 This limitation is also present in claim 8, the only other independent claim on
appeal.
Appeal 2012-003422
Application 11/441,767

3

Rejections of claims 1, 5-8, 10, 13, and 14 under 35 U.S.C. §102(b)
as anticipated by or, in the alternative, under 35 U.S.C. §103(a)
as unpatentable over Yamatsu or Hanrahan
The Examiner finds Yamatsu and Hanrahan each discloses methods which
include simultaneously heating a photoresist and exposing it to radiation. (Ans.5 5-
6.) The Examiner concedes the references fail to explicitly teach a step of
“forming more than one acid in a photoresist per absorbed photon.” (Id. at 5.)
However, the Examiner finds that “because known photoacid generators can be
used in [Yamatsu and Hanrahan], those photoacid generators, if processed in the
manner as disclosed, would inherently form more than one acid per photon because
of the inseparable nature of the compounds and its [sic] properties when heated and
exposed.” (Id. at 5.) The Examiner determines, in the alternative, “[i]t would have
been prima facie obvious to one of ordinary skill in the art of photoresist
processing to duplicate the process steps of [Yamatsu or Hanrahan] and reasonably
expect [the] same or similar results for the formation of more than one acid per
photon and the expectation [sic] of forming improved photoresist properties.” (Id.)
Appellants argue the Examiner’s rejections are based on an erroneous and
unsupported finding that a step of “forming more than one acid in a photoresist per
absorbed photon” necessarily occurs in any method wherein a photoresist is
simultaneously heated and exposed to radiation, irrespective of the particular
photoacid generator and other process conditions. (See Br. 9.) Appellants direct
us to the Specification in support of their contention that specific techniques are
required to form more than one acid in a photoresist per absorbed photon. (Id.
(citing Spec. 3:4-10, 4:9-26); see also, Spec. 6:1-15 (identifying process conditions
necessary to ensure formation of more than one acid in a photoresist per absorbed

5 Examiner’s Answer mailed Oct. 4, 2011.
Appeal 2012-003422
Application 11/441,767

4
photon); id. at 8:15-10:11 (calculations to determine optimum process
temperature).)
The Examiner, in response, does not attempt to establish that the references
use process conditions which are the same as, or similar to, those used by
Appellants to achieve formation of more than one acid in the photoresist. (See
Ans. 7-8.) In fact, the Examiner does not clearly direct us to disclosure, or provide
explanation, to support a finding that Yamatsu and Hanrahan teach or suggest
“heating the photoresist to a temperature less than about 25°C below the glass
transition temperature of the photoresist” as required by the appealed claims. (See
generally, Ans. 4-8.) Accordingly, the Examiner has not provided a reasonable
basis for concluding the methods of Yamatsu and Hanrahan inherently include a
step of “forming” as recited in appealed claim 1.6 Nor has the Examiner provided
persuasive argument or evidence to support a finding that a step of forming more
than one acid in a photoresist per absorbed photon necessarily occurs in any
method wherein a photoresist is simultaneously heated and exposed to radiation.7

6Cf. In re Best, 562 F.2d 1252, 1255 (CCPA 1977) (“Where . . . the claimed and
prior art products are identical or substantially identical, or are produced by
identical or substantially identical processes, the PTO can require an applicant to
prove that the prior art products do not necessarily or inherently possess the
characteristics of his claimed product. Whether the rejection is based on
‘inherency’ under 35 U.S.C. § 102, on ‘prima facie obviousness’ under 35 U.S.C. §
103, jointly or alternatively, the burden of proof is the same, and its fairness is
evidenced by the PTO’s inability to manufacture products or to obtain and
compare prior art products.”).

7Cf. In re Kubin, 561 F.3d 1351, 1357 (Fed. Cir. 2009) (“Even if no prior art of
record explicitly discusses the . . . [limitation], [Appellants’] application itself
instructs that [the limitation] is not an additional requirement imposed by the
claims on the [claimed invention], but rather a property necessarily present in [the
claimed invention].”)

Appeal 2012-003422
Application 11/441,767

5
Because the facts and reasons relied on by the Examiner are insufficient to
support a prima facie case of anticipation or obviousness, we do not sustain the
rejections of claims 1, 5-8, 10, 13, and 14 under 35 U.S.C. §102(b) as anticipated
by or, in the alternative, under 35 U.S.C. §103(a) as unpatentable over Yamatsu or
Hanrahan.

Rejection of claims 1, 4-8, 10, and 12-14 under 35 U.S.C. §103(a) as unpatentable
over Yamatsu or Hanrahan in view of Ohsawa
Appealed claims 4 and 12 depend from independent claims 1 and 8,
respectively, and require using “a photoresist with a photoacid generator of the bis-
sulphonyl-substituted diazomethane type.” The Examiner concedes Yamatsu and
Hanrahan “lack the explicit use of a diazomethane.” (Ans. 6.) The Examiner finds
Ohsawa:
disclose[s] photoresist compositions which use several photoacid
generators in the alternative to include bis(cyclohexylsulfonyl)
diazomethane among a list of other equivalent photoacids, see column
50, lines 1-13.8 This directs the skilled artisan to reasonably expect
same or similar results when using any of the listed photoacid
generators.
It would have been prima facie obvious to one of ordinary skill
in the art of photoresist composition to use any of the listed photoacid
generators in the processing steps of [Yamatsu or Hanrahan] and
reasonably expect to have a photoresist with excellent
photolithographic properties.
(Ans. 6).

8 The cited portion of Ohsawa is nothing more than a list of photoacid generators
used in the preparation of Example and Comparative Example resist compositions.
The Examiner has not explained how/why these photoacid generators are believed
to be “equivalent photoacids” and, more particularly, why they would all be
reasonably expected to form more than one acid in a photoresist per absorbed
photon.
Appeal 2012-003422
Application 11/441,767

6
We agree with Appellants that the Examiner has failed to establish a prima
facie case of obviousness because the Examiner has not explained how Yamatsu or
Hanrahan, as modified by Ohsawa to use a diazomethane, would necessarily or
inherently result in a method which includes a step of “forming more than one acid
in a photoresist per absorbed photon” as required by the appealed claims. As
argued by Appellants (see supra pp. 3-4), the Examiner has not identified
disclosure in the references which supports a finding that the references use
process conditions which are the same as or similar to those used by Appellants to
achieve formation of more than one acid in the photoresist. Accordingly, we do
not sustain the rejection of claims 1, 4-8, 10, and 12-14 under 35 U.S.C. §103(a) as
unpatentable over Yamatsu or Hanrahan in view of Ohsawa.

REVERSED

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