Patent ID: 7871753

Claim:
A positive resist composition, which comprises a resin component (A) in which alkali solubility increases under the action of an acid, and an acid generator component (B) which generates an acid upon exposure, wherein the resin component (A) comprises a polymer compound (A1)′, wherein the polymer compound (A1)′ consists of a structural unit (a0) containing a carboxyl group, at least one structural unit (a1) selected from the group consisting of a structural unit represented by a general formula (a1-2) shown below and a structural unit represented by a general formula (a1-4) shown below: (wherein, Y represents an aliphatic cyclic group or a lower alkyl group of 1 to 5 carbon atoms; n represents 0; m represents 0 or 1; R represents a hydrogen atom, a halogen atom, a lower alkyl group of 1 to 5 carbon atoms, or a halogenated lower alkyl group of 1 to 5 carbon atoms; and R 1 ′ and R 2 ′ each independently represents a hydrogen atom or a lower alkyl group of 1 to 5 carbon atoms), a structural unit (a2)′ derived from hydroxystyrene, and a structural unit (a3)′ derived from styrene, wherein the structural unit (a0) comprises a structural unit represented by general formulae (a0-1) and/or (a0-2) shown below: (wherein R represents a hydrogen atom, a halogen atom, a lower alkyl group of 1 to 5 carbon atoms or a halogenated lower alkyl group of 1 to 5 carbon atoms; and R′ represents a chain or cyclic alkylene group).