Ex Parte Le et al

Board of Patent Appeals and Interferences

Mar 27, 2009

10866563 (B.P.A.I. Mar. 27, 2009)

UNITED STATES PATENT AND TRADEMARK OFFICE
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BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
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Ex parte NGOC V. LE,
WILLIAM J. DAUKSHER,
and DOUG J. RESNICK
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Appeal 2008-6175
Application 10/866,563
Technology Center 1700
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Decided:1 March 27, 2009
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Before CHARLES F. WARREN, TERRY J. OWENS, and
MICHAEL P. COLAIANNI, Administrative Patent Judges.

OWENS, Administrative Patent Judge.

DECISION ON APPEAL
STATEMENT OF THE CASE

1 The two-month time period for filing an appeal or commencing a civil
action, as recited in 37 C.F.R. § 1.304, begins to run from the Decided Date
shown on this page of the decision. The time period does not run from the
Mail Date (paper delivery) or Notification Date (electronic delivery).

Appeal 2008-6175
Application 10/866,563

The Appellants appeal under 35 U.S.C. § 134(a) from the Examiner’s
rejection of claims 1-40, which are all of the pending claims. We have
jurisdiction under 35 U.S.C. § 6(b).
The Invention
The Appellants claim a method for forming a semiconductor device
wherein a transfer layer is etched using a mixture of nitrogen and
hydrogen.2,3 Claim 1 is illustrative:
1. A method for forming a semiconductor device comprising:

providing a substrate;

forming a transfer layer on the substrate;

forming an etch barrier layer on the transfer layer, the etch barrier
layer comprising one of an organic monomer, a silicon containing monomer,
or a mixture of monomers;

patterning the etch barrier layer with a template applied in direct
contact to the etch barrier layer while curing with radiation through the
template, resulting in a patterned etch barrier layer and a residual layer on
the transfer layer;

performing an etch to substantially remove the residual layer; and

performing an etch with a mixture of nitrogen and hydrogen to
substantially remove the portion of the transfer layer not underlying the
pattern etch barrier layer.

2 The disclosed transfer layer is an antireflective coating (Spec. ¶ 0018).
3 The Appellants’ term “mixture of nitrogen and hydrogen” includes
ammonia (Spec. ¶ 0017).
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Appeal 2008-6175
Application 10/866,563

The References
Gupta 5,910,453 Jun. 8, 1999
Willson 6,334,960 B1 Jan. 1, 2002
Nakagawa 6,451,620 B2 Sep. 17, 2002
Keil 6,630,407 B2 Oct. 7, 2003
The Rejections
The claims stand rejected under 35 U.S.C. § 103 as follows: claims
1-8, 10-13, 15-28, 30-33, and 35-40 over Willson in view of Nakagawa;
claims 14 and 34 over Willson in view of Nakagawa and Gupta; and
claims 9 and 29 over Willson in view of Nakagawa and Keil.
OPINION
We affirm the Examiner’s rejections.
The Appellants argue claims 1-8, 10-13, 15-28, 30-33, and 35-40 as a
group (Br. 11-18). The Appellants point out what claims 13, 14, 17, 18, 21,
33, 34, 37, and 38 recite (Br. 15-16), but merely pointing out what claims
recite is not an argument for the separate patentability of the claims. Hence,
we limit our discussion of claims 1-8, 10-13, 15-28, 30-33, and 35-40 to one
claim, i.e., claim 1. Claims 2-8, 10-13, 15-28, 30-33, and 35-40 fall with
claim 1. See 37 C.F.R. § 41.37(c)(1)(vii) (2007). With regard to claims 9,
14, 29, and 34 the Appellants rely upon the argument set forth with respect
to claims 1-8, 10-13, 15-28, 30-33, and 35-40 (Br. 19-22). For the reasons
given regarding claim 1, we are not persuaded of reversible error in the
rejection of claims 9, 14, 29, and 34.
Issue
Have the Appellants shown reversible error in the Examiner’s
determination that Willson and Nakagawa would have rendered prima facie
obvious, to one of ordinary skill in the art, the use of a mixture of nitrogen
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Application 10/866,563

and hydrogen to selectively etch Willson’s transfer layer 20 with respect to
polymeric material 70?
Findings of Fact
Willson discloses a step and flash imprint lithography method wherein
a transfer layer (20) is formed on a substrate (10), an etch barrier
(polymerizable fluid 60) is formed on the transfer layer, the etch barrier is
patterned by direct contact with a template (mold 40) and is polymerized by
exposure to radiation to form solidified polymeric material (70), residual
material is removed, and transfer layer 20 is selectively etched relative to
solidified material 70 such that a relief image 80 corresponding to the image
in mold 40 is formed in transfer layer 20 (col. 4, l. 10 – col. 5, l. 11). “The
transfer layers are formed from materials known in the art such as, for
example, thermoset polymers, thermoplastic polymers, polyepoxies,
polyamides, polyurethanes, polycarbonates, polyesters, and combinations
thereof” (col. 3, ll. 12-16). The polymerizable fluid materials are silicon-
containing materials including, but not limited to, silanes, silyl ethers, silyl
esters, functionalized siloxanes, silsesquioxanes, and mixtures thereof,
preferably organosilicons (col. 3, ll. 31-35). “The silicon-containing
materials preferably contain the element silicon in an amount greater than
about 8 percent based on the weight of the polymerizable fluid composition,
and more preferably greater than about 10 weight percent” (col. 3, ll. 35-39).
The selective etching of transfer layer 20 with respect to solidified polymeric
material 70 “may be carried out by subjecting the transfer layer 20 and the
solid polymeric material 70 to an environment such as, but not limited to, an
argon ion stream, an oxygen-containing plasma, a reactive ion etching gas, a
halogen-containing gas, a sulfur dioxide-containing gas, and a combination
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Appeal 2008-6175
Application 10/866,563

of the above” (col. 4, ll. 57-62). Willson’s method differs from the method
claimed in the Appellants’ claim 1 in that this list of etching environments
does not include a mixture of nitrogen and hydrogen.
Nakamura discloses that it was known in the semiconductor art to etch
organic films using gases including nitrogen and hydrogen as principal
constituents and including ammonia as a principal constituent (col. 1, l. 31 –
col. 2, l. 10). In Conventional Example 1 wherein the etchant gas is
nitrogen/hydrogen, a silicon oxide mask film is used in etching the organic
film (col. 2, ll. 6-7).
Analysis
The Appellants argue that Willson’s polymerizable monomer
(polymerizable fluid 60) cannot be used in Nakamura’s conventional
lithography because it does not have the proper chemical composition to be
exposed and developed, and Nakamura’s conventional resist cannot be used
in Willson’s step and flash imprint lithography because it does not conform
to the features during contact made with the mask to produce an acceptable
pattern (Br. 13; Reply Br. 2).
Prima facie obviousness of the invention claimed in the Appellants’
claim 1 does not require substituting Nakamura’s resist for Willson’s etch
barrier. All that is required is the use of Nakamura’s disclosed conventional
prior art nitrogen/hydrogen or ammonia etchant gas as Willson’s etchant gas.
One of ordinary skill in the art would have been led, through no more than
ordinary creativity, to do so by Nakamura’s disclosure that the conventional
nitrogen/hydrogen and ammonia etchant gases are effective for etching
organic films (col. 1, ll. 31-39), and Willson’s disclosure that etch barrier 20
is an organic film (col. 3, ll. 12-16). See KSR Int’l. Co. v. Teleflex Inc.,
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Appeal 2008-6175
Application 10/866,563

127 S. Ct. 1727, 1741 (2007) (In making an obviousness determination one
“can take account of the inferences and creative steps that a person of
ordinary skill in the art would employ”). One of ordinary skill in the art
would have had a reasonable expectation of success in doing so in view of
Nakamura’s disclosure of the use of nitrogen/hydrogen to etch an organic
film using a silicon oxide film as a mask (col. 1, l. 50 – col. 2, l. 10), and
Willson’s disclosure that solidified polymeric material 70 with respect to
which etch barrier 20 is selectively etched can be an oxygen-containing
silicon material (col. 3, ll. 27-35). See In re O’Farrell, 853 F.2d 894, 904
(Fed. Cir. 1988) (“Obviousness does not require absolute predictability of
success . . . For obviousness under § 103, all that is required is a reasonable
expectation of success”).
The Appellants argue that Nakagawa indicates with respect to
Conventional Examples 1-5 that ammonia cannot work for Nakamura’s
organic film and that nitrogen/hydrogen are not a universal solution for all
organic systems (Br. 14).
Nakagawa’s only conventional example in which nitrogen/hydrogen
is specifically disclosed is Conventional Example 1 which, Nakagawa states,
resulted in an etched hole having, as shown by a detailed observation, a
bowing shape (col. 5, ll. 13-27). That disclosure does not indicate that
nitrogen/hydrogen is ineffective for etching organic films but, rather, merely
indicates that a hole etched in an organic film using nitrogen/hydrogen will
have a slightly bowed shape.
The Appellants argue that their method is different from any other
semiconductor method because the Appellants’ etch barrier has about
9 percent silicon (Br. 14).
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Appeal 2008-6175
Application 10/866,563

The Appellants’ claim 1 is not limited to any etch barrier silicon
content. Regardless, Willson discloses that the etch barrier material
preferably contains greater than about 8 wt% silicon (col. 3, ll. 35-35),
which encompasses the Appellants’ 9 percent.
The Appellants argue that Willson and Nakamura do not recognize the
problem solved by the Appellants (Br. 17).
That argument is not persuasive because for a prima facie case of
obviousness to be established, the references need not be combined for the
purpose of solving the problem solved by the Appellants. See In re Kemps,
97 F.3d 1427, 1430 (Fed. Cir. 1996); In re Beattie, 974 F.2d 1309, 1312
(Fed. Cir. 1992); In re Dillon, 919 F.2d 688, 693 (Fed. Cir. 1990) (en banc).

Conclusion of Law
The Appellants have not shown reversible error in the Examiner’s
determination that Willson and Nakagawa would have rendered prima facie
obvious, to one of ordinary skill in the art, the use of a mixture of nitrogen
and hydrogen to selectively etch Willson’s transfer layer 20 with respect to
polymeric material 70.
DECISION/ORDER
The rejections under 35 U.S.C. § 103 of claims 1-8, 10-13, 15-28,
30-33 and 35-40 over Willson in view of Nakagawa, claims 14 and 34 over
Willson in view of Nakagawa and Gupta, and claims 9 and 29 over Willson
in view of Nakagawa and Keil are affirmed.
It is ordered that the Examiner’s decision is affirmed.

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Appeal 2008-6175
Application 10/866,563

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

cam

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