Patent ID: 8268530

Claim:
A positive resist composition comprising a base component (A) which exhibits increased solubility in an alkali developing solution under action of acid and an acid generator component (B) which generates acid upon exposure, wherein said base component (A) comprises a polymeric compound (A1) comprising a structural unit (a0) containing an acid-dissociable, dissolution-inhibiting group, and said structural unit (a0) is a structural unit represented by general formula (a0-1′) shown below: wherein R represents a hydrogen atom, an alkyl group of 1 to 5 carbons or a halogenated alkyl group of 1 to 5 carbons, Y 01 represents a divalent organic group that becomes an alkali-soluble group upon cleavage of a bond to Y 02 under action of an acid, Y 02 represents a single bond or a divalent linking group, which substitutes 1 hydrogen atom of a group within brackets [ ] of formula (a0-1′) that is derived from either a 1,3-benzodioxole or a derivative thereof, R 11 represents a hydrocarbon group of 1 to 30 carbon atoms that may have a substituent, t represents an integer of 0 to 3, and in those cases where t is 2 or 3, a plurality of R 11 groups may be bonded together to form a ring, or may be bonded to a benzene ring to form an aromatic ring, R 10 may be a hydrogen atom or an alkyl group of 1 to 5 carbon atoms which may have a substituent, R 10′ represents a hydrogen atom or an alkyl group of 1 to 5 carbon atoms which may have a substituent, and R 10 and R 10′ may be bonded together to form a ring.