Patent ID: 8361693

Claim:
A chemically amplified positive photoresist composition comprising a polymer comprising recurring units having the general formulae (1) to (3) or (1) to (4): wherein R 1 is hydrogen, fluorine, methyl or trifluoromethyl, R 2 is hydrogen, a substituted or unsubstituted, straight, branched or cyclic C 1 -C 10 alkyl group, or a substituted or unsubstituted, straight, branched or cyclic C 1 -C 10 alkoxy group, R 3 is each independently a C 1 -C 10 alkyl group, A is a single bond or a divalent C 1 -C 10 organic group which may be separated by an ether bond, B is a benzene ring or fused polycyclic aromatic group comprising up to 3 aromatic rings, s is each independently 0 or 1, u is 0 or 1, a is each independently an integer of 0 to 3, b and c are each independently an integer of 1 to 3, X is an acid labile group when c is 1, X is hydrogen or an acid labile group when c is 2 or 3, at least one X is an acid labile group, and Q has the general formula (5) or (6): wherein R 6 is each independently hydrogen, hydroxyl, C 1 -C 7 alkylcarbonyloxy or C 1 -C 6 alkyl, alkoxy, haloalkyl or haloalkoxy group, and d is an integer of 0 to 4, the units of formula (1) accounting for up to 10 mol % based on the entire units of the polymer.