Patent ID: 7666967

Claim:
A polymer comprising recurring units having the general formula (2), recurring units having the general formula (3) and recurring units having the general formula (4), the polymer having a weight average molecular weight of 1,000 to 500,00, wherein R 1 is a fluorine atom or a straight or branched fluorinated alkyl group of 1 to 6 carbon atoms, R 2 is a hydrogen atom or a straight, branched or cyclic alkyl group of 1 to 8 carbon atoms, R 3 is an oxygen atom or a straight, branched or cyclic alkylene group of 1 to 6 carbon atoms, R 4 and R 5 each are a hydrogen atom or a straight, branched or cyclic alkyl or fluorinated alkyl group of 1 to 10 carbon atoms, R 6 is a hydrogen atom or an acid labile group, R 10 is a hydrogen atom, a straight, branched or cyclic fluorinated alkyl group of 1 to 10 carbon atoms, an acid labile group, or an adhesive group, the subscripts a1 and a2 are 0<a1<1, 0<a2<1, and 0<a1+a2≦1 and the subscript b is 0 or 1, said recurring units (3) are selected from the group consisting of the following units: wherein R 9 is hydrogen or an acid labile group.