Patent ID: 8062831

Claim:
A polymer comprising recurring units having the general formulae (2), (3), (4) and (5): wherein R 1 is hydrogen or methyl, R 2 and R 3 are each independently hydrogen or a straight, branched or cyclic monovalent C 1 -C 10 hydrocarbon group, or R 2 and R 3 may bond together to form an aliphatic hydrocarbon ring with the carbon atom to which they are attached, W is —CH 2 —, —S— or —O—, k 1 is an integer of 0 to 4, and k 2 is 0 or 1 wherein R 1 is hydrogen, fluorine, methyl or trifluoromethyl, R 4 and R 5 are each independently hydrogen or hydroxyl, X is an acid labile group, and Y is a substituent group having a lactone structure; wherein the recurring unit having the general formula (5) is selected from the group consisting of the following formulae: