Patent ID: 8753795

Claim:
A photoresist composition comprising a resin which comprises a structural unit derived from a compound having an acid-labile group and which is insoluble or poorly soluble in an alkali aqueous solution but becomes soluble in an alkali aqueous solution by the action of an acid, an acid generator and a compound represented by the formula (I): wherein R 1 represents a hydroxyl group, a C1-C8 alkyl group, a C3-C12 alicyclic hydrocarbon group or a C6-C18 aromatic hydrocarbon group, and one or more hydrogen atom in the alicyclic hydrocarbon group and the aromatic hydrocarbon group may be substituted with a hydroxyl group or a C1-C6 alkyl group, and one or more —CH 2 — in the alicyclic hydrocarbon group may be replaced by —O—, —CO—, —S— or —SO 2 —, X 1 represents a C1-C12 divalent saturated hydrocarbon group in which one or more —CH 2 — are replaced by —CO— and may be replaced by —O—, R 2 is independently in each occurrence a C1-C12 saturated hydrocarbon group, u1 represents an integer of 0 to 2, s1 represents 1 or 2, t1 represents 0 or 1 with the proviso that sum of s1 and t1 is 1 or 2.