Patent ID: 7125643

Claim:
A polymer comprising recurring units of the general formula (1) and recurring units of at least one type selected from the general formulae (2a) to (2d) and having a weight average molecular weight of 1,000 to 500,000, wherein R 1 is a fluorine atom or a fluorinated alkyl group of 1 to 4 carbon atoms, R 2 is a single bond or a straight, branched or cyclic alkylene or fluorinated alkylene group of 1 to 20 carbon atoms, R 3 and R 4 each are a hydrogen atom, a fluorine atom or a straight, branched or cyclic alkyl or fluorinated alkyl group of 1 to 20 carbon atoms, at least one of R 3 and R 4 contains at least one fluorine atom, R 5 is hydrogen or an acid labile group, R 6 is an acid labile group, an adhesive group or a straight, branched or cyclic alkyl or fluorinated alkyl group of 1 to 20 carbon atoms, and “a” is 1 or 2.