Vinyl 4-t-butoxycarbonyloxybenzal-vinyl alcohol-vinyl acetate copolymer, vinyl 4-t-butoxycarbonyloxybenzal-vinyl 4-hydroxybenzal-vinyl alcohol-vinyl acetate and preparation methods thereof

Abstract

There is a vinyl 4-hydroxybenzal-vinylalcohol-vinyl acetate copolymer, a 4-t-butoxycarbonyloxybenzal-vinyl alcohol-vinyl acetate copolymer and a vinyl 4-t-butoxycarbonyloxybenzal-vinyl 4-hydroxybenzal-vinyl alcohol-vinyl acetate copolymer suitable for photoresist and methods for preparing the same. The latter two polymers contain 4-hydroxybenzal groups all or parts of which are protected with t-butoxycarbonyl group. Superior in transparency, thermal stability, mechanical strength, and adhesiveness to silicon wafer, the photoresists prepared from the protected copolymers can enhance the resolution of fine circuit by virtue of low weight loss upon the thermal treatment after exposure.

Dependencies are inferred from the claim text.