Patent ID: 7504193

Claim:
A positive resist composition comprising: (A) a resin of which solubility in an alkali developer increases under the action of an acid, the resin having a repeating unit represented by formula (I) and a repeating unit represented by formula (IIa), (B) a compound of generating an acid upon irradiation with actinic rays or radiation, and (C) an organic basic compound: wherein R 1 represents a hydrogen atom, a methyl group, a cyano group, a halogen atom or a perfluoro group, R 2 represents a non-acid-decomposable group, selected from the group consisting of a halogen atom, a cyclolkyl group, an aryl group, an alkoxy group, an acyl group, —OC(═O)Ra, —OC(═O)ORa, —C(═O)ORa, —C(═O)N(Rb)Ra, —N(Rb)C(═O)Ra, —N(Rb)C(═O)ORa, —N(Rb)SO 2 Ra, —SRa, —SO 2 Ra, —SO 3 Ra and —SO 2 N(Rb)Ra in which Ra represents an alkyl group, a cycloalkyl group or an aryl group and Rb represents a hydrogen atom, an alkyl group, a cycloalkyl group or an aryl group, X represents a hydrogen atom or an organic group, m represents an integer of 1 to 4, n represents an integer of 1 to 4, provided that 2≦n+m≦5, when m is an integer of 2 to 4, multiple Xs may be the same or different, when n is an integer of 2 to 4, multiple R 2 s may be the same or different, and R 1 in formula (IIa) may be the same as or different from R 1 in formula (I), respectively, and X 2 represents a hydrogen atom or an acid-decomposable group.