Ex Parte Lin et al

Board of Patent Appeals and Interferences

Jul 26, 2011

11043304 (B.P.A.I. Jul. 26, 2011)

UNITED STATES PATENT AND TRADEMARK OFFICE
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.
11/043,304 01/26/2005 Chin-Hsiang Lin 2004-0310 / 24061.530 8790
42717 7590 07/27/2011
HAYNES AND BOONE, LLP
IP Section
2323 Victory Avenue
Suite 700
Dallas, TX 75219
EXAMINER
RAYMOND, BRITTANY L
ART UNIT PAPER NUMBER
1722
MAIL DATE DELIVERY MODE
07/27/2011 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 CHIN-HSIANG LIN and BURN JENG LIN
________________

Appeal 2010-012043
Application 11/043,304
Technology Center 1700
________________

Before LINDA M. GAUDETTE, KAREN M. HASTINGS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

HASTINGS, Administrative Patent Judge.

DECISION ON APPEAL
Appellants seek our review under 35 U.S.C. § 134(a) of the
Examiner's final decision rejecting claims 1-16, 20-27, and 29. We have
jurisdiction over the appeal under 35 U.S.C. § 6(b).
We AFFIRM.

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STATEMENT OF THE CASE
The disclosed invention relates generally to a system and method of
interferometric photolithography for producing patterns in a photosensitive
material. Claim 1 is illustrative of the claimed invention:
1. A method for producing a pattern on a substrate,
the method comprising:
separating the pattern into at least a first sub-
pattern containing a plurality of lines oriented in a
first direction and a second sub-pattern containing
a plurality of lines oriented in a second direction;
creating a first plurality of lines oriented in the first
direction on a first layer of photosensitive material
on the substrate using a first standing wave
interference pattern;
trimming a portion of the created first plurality of
lines to create the first sub-pattern;
applying a second layer of photosensitive material
to the substrate after creating the first sub-pattern;
creating a second plurality of lines oriented in the
second direction on the second layer using a
second standing wave interference pattern; and
trimming a portion of the created second plurality
of lines to create the second sub-pattern.
The Examiner maintains the following rejections:
Claims 1-10 and 14-16 stand rejected under 35 U.S.C. § 103(a) as
being unpatentable over the combined prior art of Brueck (U.S. 5,415,835
issued May 16, 1995) in view of Fritze (U.S. 6,818,389 B2 issued Nov. 16,
2004).
Claims 11-13 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over the combined prior art of Brueck in view of Fritze, and
further in view of Brueck II (U.S. 5,216,257 issued Jun. 1, 1993).
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Claims 20-27 and 29 stand rejected under 35 U.S.C. § 103(a) as being
unpatentable over the combined prior art of Brueck in view of Fritze, and
further in view of Taniguchi (U.S. 5,225,918 issued Jul. 6, 1993).
These rejections are addressed below. There are two independent
claims on appeal: claims 1 and 25. Appellants do not separately argue with
any reasonable specificity any of the individual dependent claims (see App.
Br. 15-16, 21). Independent claim 1 has been selected to address the issues
on appeal, and independent claim 25 is also separately addressed.
MAIN ISSUES
Did the Examiner reversibly err in determining that the method of
claim 1 would have been obvious under 35 U.S.C. § 103 over the method of
producing two-dimensional patterns on photosensitive layers of Brueck in
view of the trimming procedure of Fritze?
Did the Examiner reversibly err in determining that the method of
claim 25 would have been obvious under 35 U.S.C. § 103 over the method
of producing two-dimensional patterns on photosensitive layers of Brueck in
view of the trimming procedure of Fritze and the coherent optical beams of
Taniguchi?
PRINCIPLES OF LAW
In assessing whether a claim to a combination of prior art elements or
steps would have been obvious, the question to be asked is whether the
improvement of the claim is more than the predictable use of prior art
elements or steps according to their established functions. KSR Int’l Co. v.
Teleflex Inc., 550 U.S. 398, 417 (2007). The analysis need not seek out
precise teachings directed to the specific subject matter of the claim, for it is
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proper to take account of the inferences and creative steps that a person of
ordinary skill in the art would employ. Id. at 418.
“For obviousness under § 103, all that is required is a reasonable
expectation of success.” In re O’Farrell, 853 F.2d 894, 903-04 (Fed. Cir.
1988).
Arguments and conclusions unsupported by factual evidence carry no
evidentiary weight. In re De Blauwe, 736 F.2d 699, 705 (Fed. Cir. 1984); In
re Lindner, 457 F.2d 506, 508 (CCPA 1972). Without supporting evidence,
arguments and conclusory statements by the inventor cannot establish
patentability. In re De Blauwe, supra; In re Swan Wood, 582 F.2d 638, 642
(CCPA 1978).
ANALYSIS
We have thoroughly reviewed each of Appellants’ arguments for
patentability. However, we are in agreement with the Examiner that the
claimed subject matter would have been obvious to one of ordinary skill in
the art within the meaning of § 103 in view of the applied prior art. We add
the following primarily for emphasis.

Claim 1
Appellants argue that the claimed limitations requiring the creation of
a first and second plurality of lines are not taught by the combined
references of Brueck and Fritze (see App. Br. 10-13; see also Reply 5-8).
Rather, the Appellants state that Brueck “illustrates sub-patterns of dots, or
circles, not lines.” (App. Br. 12). Appellants’ argument is not persuasive for
the reasons aptly explained by the Examiner (Ans. 8). Although the
embodiment of Brueck shown in Figure 3 does show an array of dots (see
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Brueck Fig. 3), this array was created, as stated by the Examiner, by using
an interference pattern or “plurality of lines” in one direction, then rotating
the photosensitive material by 90 degrees while all other parameters were
unchanged, and then repeating the interference pattern or “plurality of lines”
in a second direction (see Brueck Fig. 3; col. 4, lines 53-66; see also Ans. 8-
9). The difference between the array of dots as shown in Brueck’s Figure 3
and the creation of a grid pattern is merely the difference between using a
positive photoresist rather than a negative photoresist, which was well
known in the photolithography art at the time of the present invention (see,
e.g., Fritze col. 1, lines 59-62). Further, Brueck directly contradicts
Appellants’ assertion that Brueck only discloses an array of dots. (Cf.
Brueck Fig. 3; col. 5, lines 40-55 with App. Br. 10-13, Reply 5-8) by stating:
It is clear from the images produced in connection with
FIGS. 3 thru 14 that, in accordance with the invention, many
other complex patterns may be produced in the manner
described. The examples . . . by no means exhaust the rich
array of possibilities of patterns including those required for
highly repetitive integrated circuit elements such as DRAMs.
. . .
It is understood that in accordance with the invention a
very wide range of structures that can be fabricated.

(Brueck, col. 5, ll. 40-55, emphasis added).

Therefore, the Examiner’s position that Brueck discloses
forming a first plurality of lines oriented in a first direction and a
second plurality of lines oriented in a second direction is reasonable.
Appellants’ argument that Brueck cannot be properly combined with
Fritze because Fritze teaches away from Brueck (see App. Br. 13-15; Reply
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8-10) is unavailing. To support their position, Appellants rely upon Fritze at
column 3, lines 34-45 (App. Br. 14-15), which states:
U.S. Pat. No. 5,415,835-B1 ("Brueck et al.") discusses a
method of fine-line imaging based on laser interferometry. In
Brueck et al., dense gratings formed by laser interferometry are
customized by additional exposures using both interferometric
and conventional lithography. Brueck et al. does not address
optical proximity and spatial frequency effect problems thus
limiting the ultimate density and flexibility of the patterns
produced. In addition, the multiple exposures are not
substantially independent in the optical sense due to the resist's
"memory" of previous exposure patterns. It is also difficult to
make an arbitrary two-dimensional pattern in this way.

(Fritze, col. 3, ll. 34-45).

Appellants assert that to be “substantially independent” in the optical
sense as taught by Fritze (see Fritze, col. 4, ll. 29-33), each exposure
requires a separate independent photoresist (see App. Br. 15). Appellants
also contend that Brueck only discloses “exposing a single photoresist layer
to two exposures” (App. Br. 15). To the contrary, Brueck does teach
multiple photoresists, as aptly cited by the Examiner (see Ans. 4), as Brueck
states:
As an alternative method, first a single or multiple set of
interferometric exposures are carried out in photosensitive
layer. The subsequent pattern is then developed and transferred
to a semiconductor substrate by any of the well known
commercially available techniques. This substrate is then again
recoated with a photoresistive layer, and single or multiple
exposure processes can be repeated with the aid of the
alignment position sensing arrangement described in Brueck, et
al. in U.S. Pat. No. 4,987,461.

(Brueck col. 4, ll. 31-40, emphasis added.)
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Accordingly, Brueck is not limited to “exposing a single photoresist
layer to two exposures” as Appellants urge (App. Br. 15). Further,
Appellants’ reliance upon Fritze at col. 3, ll. 34-45 (reproduced above) as
teaching away from Brueck is not persuasive, noting that our reviewing
Court has held that "[a] reference can distinguish prior art in order to show
the novelty of an invention without teaching away from combining the prior
art with the invention disclosed in the reference.” See In re Katz Interactive
Call Processing Patent Litig., 639 F.3d 1303, 1321 (Fed. Cir. 2011). When
determining if a reference teaches away from an invention, all of the
teachings of the reference must be considered in totality. W.L. Gore &
Assoc., Inc. v. Garlock, Inc., 721 F.2d 1540, 1550-51 (Fed. Cir. 1983). We
have weighed the evidence as is required, see In re Gurley, 27 F.3d 551, 553
(Fed. Cir. 1994) (providing that teaching away is a significant factor, but the
nature of the teaching is highly relevant, and must be weighed in substance),
and when considered in totality, the Examiner’s determination that Fritze
does not teach away from the invention of Brueck is reasonable.
Furthermore, “[a] person of ordinary skill is also a person of ordinary
creativity, not an automaton.” KSR , 550 U.S. at 421. The Examiner's
position is reasonable in view of the applied prior art, and Appellants have
not provided any convincing technical reasoning or evidence that one of
ordinary skill in the art would not have, using no more than ordinary
creativity, successfully used trimming steps between each exposure (see
generally App. Br.; Reply Br.). In this context, the use of exposures and
trimming steps would have been nothing more than using known techniques
in accordance with their known functions for the predictable result of
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creating integrated circuits without spatial or proximity effects. See KSR,
550 U.S. at 415-16 (“The combination of familiar elements according to
known methods is likely to be obvious when it does no more than yield
predictable results.”).
Appellants’ additional arguments in the Appeal Brief are unavailing
because they improperly focus on the teachings of references individually
instead of addressing the Examiner's stated case for obviousness (see
generally App. Br.). “[O]ne cannot show non-obviousness by attacking
references individually where . . . the rejections are based on combinations
of references.” In re Keller, 642 F.2d 413, 426 (CCPA 1981).
On this record, Appellants have not persuaded us that the Examiner
erred in concluding that it would have been obvious for one of ordinary skill
in the lithography art at the time the invention was made, using no more than
ordinary creativity, to have performed a trimming step after each
interferometric exposure, as disclosed by Fritze, in the process of Brueck
because Brueck teaches a method of producing complex, two-dimensional
patterns in integrated circuits (see Brueck col. 2, ll. 38-61; see also Ans. 6),
and Fritze teaches that the trimming process removes optical proximity and
spatial frequency effects on photoresist patterns and can result in higher
resolution features on integrated circuits (see Fritze col. 4, ll. 15-23; see also
Ans. 6).
Accordingly, Appellants have not shown reversible error in the
Examiner's determination that the subject matter of the pending claims
would have been obvious over the combined teachings of the applied prior
art references.

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Claim 25
Pertaining to independent claim 25, Appellants argue that the
combination of Brueck in view of Fritze and in further view of Taniguchi is
improper because the Examiner did not show a motivation to combine the
references or show that the resulting combination produced a predictable
result. (See App. Br. 17-21; Reply 11-13.) This argument is not persuasive.
Specifically, Appellants assert that Taniguchi discloses a process for
making coherent beams that “results in poor imaging and beams that
inaccurately hit the photoresist layer.” (App. Br. 18, emphasis in original).
The Examiner does not dispute this (see Ans. 12-13). However, as aptly
pointed out by the Examiner, Brueck states that the coherent optical beams
required by the Brueck invention can be provided by any suitable well-
known source or sources (Brueck col. 4, ll. 5-10; see also Ans. 12-13). The
Examiner further states that the defects that may occur using the Taniguchi
apparatus can be corrected using trimming exposures, as taught by Fritze
(Fritze col. 4, ll. 42-50, see also Ans. 12-14). Notably, Appellants do not
dispute that the trimming procedure of Fritze would correct any defects
introduced by Taniguchi as asserted by the Examiner (see generally App. Br.
and see also Reply). Accordingly, without any resultant defects in the final
product, there is no disincentive for one of ordinary skill in the art to
combine the references as suggested by the Examiner.
The Appellants’ argument pertaining to the combination of Brueck in
view of Fritze (App. Br. 20-21) essentially repeats the Appellants’ argument
with respect to claim 1, and is unavailing for the reasons explained with
respect to claim 1 above.
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On this record, Appellants have not persuaded us that the Examiner
erred in concluding that it would have been obvious for one of ordinary skill
in the lithography art at the time the invention was made, using no more than
ordinary creativity, to have modified the combined process of Brueck and
Fritze discussed above using the source of coherent beams as suggested by
Taniguchi because Taniguchi teaches a well-known source of coherent
beams (see Taniguchi col. 1, ll. 53-62; see also Ans. 12-14), as required by
the Brueck invention (see Brueck col. 4, ll. 5-10; see also Ans. 12-14), and
because any defects caused by the Taniguchi source of coherent beams could
be corrected using the trimming procedure of Fritze (see Fritze col. 2, l. 45 -
col. 3, l. 9; see also Ans. 12-14).
Accordingly, Appellants have not shown reversible error in the
Examiner's determination that the subject matter of the pending claims
would have been obvious over the combined teachings of the applied prior
art references.
DECISION
We affirm the Examiner’s § 103 rejections of claims 1-16, 20-27, and
29.1

1 Only those arguments actually made by Appellants have been considered
in this decision. Arguments which could have been made but that
Appellants chose not to make have not been considered and are deemed to
be waived. See 37 C.F.R. § 41.37(c)(1)(vii) (2008).

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)(v).

AFFIRMED

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