t-Butyl norbornene carboxylates were prepared and polymerized by ring opening metathesis polymerization. The homo- and copolymers were subjected to thermal and photolytic regengeration of polymeric carboxylic acid. All the polymers exhibited high transparency toward deep UV light and wide glass transition temperature. The Tg of copolymers could be adjusted to the temperature in the range from 80℃ to 200℃ by controlling the feed ratio of TBNC and TBDOC. t-Butyl protecting group of polymers were released as isobutylene by heating to 275℃ regenerating polymeric carboxylic acid which was soluble in aqueous alkaline. Acidolytic deprotection of t-butyl group was also successfully carried out at 140℃ in the presence of acid as a catalyst. The temperature of deprotection of t-butyl group was rather low(135℃) in this case.
Therefore, the resist were formulated with the polymers oft-butyl norborene carboxylate and a photoacid generator such as triphenylsulfonium hexafluoroantimonate. Positive - tone image could be resolved by exposing the resisi film in deep UV region, post baking and developing in tetramethylammonium hydroxide solution.
