Patent ID: 7914968

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 exposure, said resin component (A) comprising a structural unit (a1) derived from hydroxystyrene, and a structural unit (a2) represented by general formula (a2-1) or (a2-2) shown below: wherein: in general formula (a2-1), R represents a hydrogen atom, a halogen atom, a lower alkyl group or a halogenated lower alkyl group; R 1 and R 2 each independently represents a hydrogen atom or a lower alkyl group; Y 1 represents a lower alkyl group or a monovalent aliphatic cyclic group; and n 21 represents an integer of 0 to 3, and in general formula (a2-2), R is as defined above; R 3 and R 4 each independently represents a hydrogen atom or a lower alkyl group; R 5 represents an alkylene group or a divalent aliphatic cyclic group; Y 2 represents a lower alkyl group or a monovalent aliphatic cyclic group; and n 22 represents an integer of 0 to 3, and said acid-generator component (B) comprising an acid generator (B1-i) having at least one anion moiety selected from the group consisting of anion moieties represented by general formulas (b-3), (b-4), and (b-5) shown below: wherein: in formula (b-3), X″ represents an alkylene group of 2 to 6 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom, in formula (b-4), Y″ and Z″ each independently represents an alkyl group of 1 to 10 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom, and in formula (b-5), U″, V″, and W″ each independently represents an alkyl group of 1 to 10 carbon atoms in which at least one hydrogen atom has been substituted with a fluorine atom, an acid generator (B1-ii) having an anion moiety represented by general formula (b-6) shown below: [Chemical Formula 3] R 10 ″—SO 3 − (b-6) wherein: in formula (b-6), R 10 ″ represents a hydrocarbon group which may or may not have a substituent, or an acid generator (B1-iii) having a cation moiety represented by general formula (b′-3) shown below: wherein: in formula (b′-3), R 7 ″ to R 9 ″ each independently represents a phenyl group or naphthyl group that may or may not have a substituent; with the proviso that the case where all of R 7 ″ to R 9 ″ represent phenyl groups which do not have a substituent is excluded.