Patent ID: 8524440

Claim:
A photoresist composition comprising a resin which comprises a structural unit represented by the formula (I): wherein Q 1 and Q 2 independently represent a fluorine atom or a C1-C6 perfluoroalkyl group, U represents a C1-C20 divalent hydrocarbon group in which one or more —CH 2 — may be replaced by —O—, —NH—, —S—, —NR c —, —CO— or —CO—O—, R c represents a C1-C6 alkyl group, X 1 represents —O—CO—, —CO—O—, —CO—O—CH 2 —, —CH 2 —O—CO—, —O—CH 2 —, —CH 2 —O—, —NR d —CO— or —CO—NR d —, R d represents a hydrogen atom or a C1-C6 alkyl group, and A + represents an organic counter ion, and a compound represented by the formula (D): wherein R 1 , R 2 , R 3 and R 4 independently represent a C1-C8 alkyl group, and A 1 represents a C3-C36 divalent saturated cyclic hydrocarbon group which can contain one or more heteroatoms and which have one or more substituents or a C6-C20 divalent aromatic hydrocarbon group which can contain one or more heteroatoms and which have one or more substituents.