Patent ID: 7645559

Claim:
A positive resist composition comprising a resin component (A) which exhibits increased alkali solubility under action of acid and an acid-generator component (B) which generates acid upon irradiation, said resin component (A) having a structural unit (a1) which is at least one member selected from the group consisting of structural units represented by general formula (a1-2) or (a1-4) shown below: wherein Y represents a lower alkyl group or an aliphatic cyclic group; n represents an integer of 0 to 3; m represents 0 or 1; R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; and R 1 ′ and R 2 ′ each independently represents a hydrogen atom or a lower alkyl group; and said acid-generator component (B) comprising an acid generator (B1) having a cation moiety represented by general formula (b-5) shown below: wherein R a and R b each independently represents an alkyl group, an alkoxy group, a halogen atom or a hydroxyl group; R c represents an aryl group or alkyl group which may or may not have a substituent; and n′ and n″ each independently represents an integer of 0 to 3.