Ex parte UEDA et al.

Board of Patent Appeals and Interferences

Mar 10, 1998

08044487 (B.P.A.I. Mar. 10, 1998)

Application for patent filed April 9, 1993.1
1
THIS OPINION WAS NOT WRITTEN FOR PUBLICATION
The opinion in support of the decision being entered today (1) was not written
for publication in a law journal and (2) is not binding precedent of the Board.
Paper No. 21
UNITED STATES PATENT AND TRADEMARK OFFICE
_____________
BEFORE THE BOARD OF PATENT APPEALS
AND INTERFERENCES
_____________
Ex parte YUJI UEDA, NAOKI TAKEYAMA,
HIROMI UEKI and TAKEHIRO KUSUMOTO
_____________
Appeal No. 95-4663
Application 08/044,4871
______________
HEARD: March 2, 1998
_______________
Before JOHN D. SMITH, GARRIS and PAK, Administrative Patent
Judges.
JOHN D. SMITH, Administrative Patent Judge.
DECISION ON APPEAL
This is an appeal pursuant to 35 USC § 134 from the final
rejection of claims 1 through 13.
Claim 1 is representative and is reproduced below:
Appeal No. 95-4663
Application 08/044,487
2
Appeal No. 95-4663
Application 08/044,487
The phrase ?chemically amplified resist? is a coined term which has been2
defined as a resist material in which exposure, followed by a post exposure bake,
results in the formation of a catalytic photoproduct, the three-dimensional
distribution of which defines the latent image. See page 54, the first full
paragraph of Lamola.
3
The references of record relied upon by the examiner are:
Renner 4,371,605 Feb. 1, 1983
Uetani et al. (Uetani) 0 460 416 A1 Dec. 11, 1991
(European Patent)
Lamola et al. (Lamola), Solid State Technology, ?Chemically
Amplified Resists?, No. 8, pages 53-60 (1991).
The appealed claims stand rejected for obviousness (35 USC
§ 103) over Uetani in view of Lamola and Renner.
We reverse.
The subject matter on appeal is directed to a chemically
amplified positive photoresist composition useful in deep2
ultraviolet lithography which composition includes an alkali-
soluble resin (referred to as a novolak resin), a dissolution
inhibitor and a photo-induced acid precursor. The alkali-soluble
novolak resin is produced through a condensation reaction of an
aldehyde with a phenol compound, including a compound of general
Appeal No. 95-4663
Application 08/044,487
4
formula (I) as set forth in appealed claim 1. The positive
photoresist composition of the present invention is said to
exhibit advantageous resolution, profile and sensitivity
properties.
The examiner’s prima facie case of obviousness is predicated
on the contention that it would have been obvious to a person of
ordinary skill in the art to modify the photoresist composition
taught by Uetani by using the dissolution inhibitor taught by
Lamola and the photoinduced acid precursor taught by Renner to
produce a positive photoresist composition, because each
component is used for its intended purpose and one would expect
that ?known components used in positive photoresists compositions
would perform in known and expected manners?. See the Answer at
pages 3 and 4. In support of this rejection the examiner
correctly factually determined that Uetani teaches a positive
photoresist composition containing an alkali soluble novolak
resin which is identical to the claimed alkali-soluble resin
(i.e., an alkali-soluble resin obtained through a condensation
reaction of an aldehyde with a phenol compound including a
compound of general formula (I) as recited in claim 1). However,
a quinone diazide compound is also an essential component of the
radiation-sensitive composition disclosed by Uetani. See Uetani
Appeal No. 95-4663
Application 08/044,487
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at page 2, line 56 to page 3, line 27. Thus Uetani’s composition
may be characterized as a positive-tone resist containing a
diazonaphthoquinone photoactive component (PAC) in combination
with a novolak resin which is referred to in the prior art as a
?PAC/novolak resist?. See Lamola at page 53, column 1, first
full paragraph.
Lamola describes a three component positive photoresist,
much like the photoresist claimed herein, which contains an
alkali soluble resin, a dissolution inhibitor and a photo-induced
acid precursor. See page 55 of Lamola. However, with respect to
the alkali soluble resin, Lamola indicates (page 55, second
column, last paragraph) that it is not a ?coincidence? that all
examples described of chemically amplified resist are based on
phenolic polymers rather than novolak resins. In fact, Lamola
indicates that while novolak resins with improved transparency
have been developed for such systems, the transparency
improvement is not adequate and the high nonbleachable absorption
properties precludes the use of such novolaks in certain systems.
See page 56, first full paragraph of the reference. Lamola also
expressly indicates that the chemically amplified resists
described are useful for deep ultraviolet lithography. However,
Appeal No. 95-4663
Application 08/044,487
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with respect to a PAC/novolak resists, Lamola indicates that the
chemistry for the deep ultraviolet lithography systems is quite
different. As set forth at page 57 of Lamola, chemically
amplified resists as described therein ?are no more difficult to
process than PAC/novolak resists; they are simply different.?
In light of the above, appellants argue, and we agree, that
it is logically inconsistent to assert that one of ordinary skill
in this art would modify Uetani’s positive photoresist
composition by using the dissolution inhibitor generally
described by Lamola. Alternatively, if one looks at Lamola as
the ?primary reference?, Lamola ?teaches away? from the use of the
alkali-soluble novolak resins such as the specific novolak resin
described by Uetani. Since we find no disclosure in Renner which
remedies the basic deficiencies in the stated rejection, we are
constrained to reverse the rejection.
For the reasons stated above, we agree with appellant that a
prima facie case of obviousness has not been established for the
subject matter defined by the claims on appeal based on the
relied upon references. This being the case, we do not find it
necessary to further consider the comparative data of record
found at pages 23 through 27 of the present specification.
Appeal No. 95-4663
Application 08/044,487
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The decision of the examiner is reversed.
REVERSED
)
JOHN D. SMITH )
Administrative Patent Judge )
)
)
) BOARD OF PATENT
BRADLEY R. GARRIS )
Administrative Patent Judge ) APPEALS AND
)
) INTERFERENCES
)
CHUNG K. PAK )
Administrative Patent Judge )
Appeal No. 95-4663
Application 08/044,487
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