Polymers, resist compositions and patterning process

摘要

A polymer comprising recurring units of formula (1) and recurring units of formulae (2a) to (2d) wherein R¹ is F or fluoroalkyl, R² is a single bond or an alkylene or fluoroalkylene, R³ and R⁴ are H, F, alkyl or fluoroalkyl, at least one of R³ and R⁴ contains F, R⁵ is H or an acid labile group, R⁶ is an acid labile group, adhesive group, alkyl or fluoroalkyl, and "a" is 1 or 2 is used as a base resin to formulate a resist composition which has advantages including high transparency to radiation having a wavelength of up to 200 nm, substrate adhesion, developer affinity and dry etching resistance.