Interference No. 104,703
Page No. 10
polymerization is said to proceed by a ring opening mechanism as opposed to the free radical or
addition polymerization techniques used to produce MA copolymers. As a result, the claimed
MA copolymers possess a different alicyclic repeating unit in the polymer backbone. Further, the
claimed MA and ROMP polymer based photoresists are said to differ structurally due to the
presence of a repeating unit polymerized from maleic anhydride in the polymer backbone. (Suwa
Preliminary Motion 1, Paper No. 31, p. 19).
Additionally, Suwa argues that Count C (MA Copolymer) defines a separately patentable
invention from Count A (AD polymer). Suwa notes that Count C is directed to resist
compositions comprising a polymer having an alicyclic skeleton comprising an acid labile
substituted alicyclic repeating unit and a repeating unit derived from maleic anhydride. As such,
Suwa states that the MA copolymer count is a sub-genus of the AD polymer count. (Paper No.
31, p. 20).
According to Kajita, as a result of the differences in the polymer structure of the MA
copolymers, the MA copolymer based resists will generally have superior resist properties as
compared to AD and ROMP polymer based resists. Kajita testifies that MA copolymer based
resists have superior swelling behavior and PAG solubility which can influence the resolution of
the images formed on the resist. (Second Declaration of Toru Kajita, SX 1004, ¶42).
Kajita has cited an article by Ito et al., “Dissolution/Swelling Behavior of Cycloolefin
Polymers in Aqueous Base,” Advances in Resist Technology and Processing XVII, Proceedings
of SPIE Vol. 3999, pp. 2-12 (2000) (hereinafter “the Ito publication”). Based upon the
swelling/dissolution behavior described in the Ito publication, Kajita testifies that significantly
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