Patent ID: 8298748

Claim:
A positive resist composition comprising a base component (A′) which exhibits increased solubility in an alkali developing solution under action of acid and generates acid upon exposure, the base component (A′) comprising a polymeric compound (A1′) comprised of a structural unit (a5-1) represented by general formula (a5-1) shown below, a structural unit (a0-1) represented by general formula (a0-1) shown below and a structural unit (a0-2) that generates acid upon exposure, the structural unit (a0-2) containing a group represented by general formula (a0-2′) shown below: wherein each R independently represents a hydrogen atom, an alkyl group of 1 to 5 carbon atoms or a halogenated alkyl group of 1 to 5 carbon atoms; R 1 represents a hydrocarbon group of at least 10 carbon atoms; R 2 represents an arylene group which may have a substituent; each of R 3 and R 4 independently represents an organic group, wherein R 3 and R 4 may be mutually bonded to form a ring with the sulfur atom; R 5 represents a substituent; a represents an integer of 0 to 4; each R 7 independently represents a hydrogen atom or an alkyl group of 1 to 5 carbon atoms; Y represents a divalent linking group; and X − represents an anion moiety represented by any one of general formulas (1) to (5) shown below, X 0 -Q 1 CF 2 p SO 3 ⊖ (1) X 0 -Q 2 -O CF 2 SO 3 ⊖ (2) X 10 -Q 3 -Y 10 —N ⊖ —SO 2 —Y 11 (3) A ⊖ (4) Y 12 CH 2 q SO 3 ⊖ (5) wherein each X 0 independently represents a hydrocarbon group of 3 to 30 carbon atoms which may have a substituent; Q 1 represents a divalent linking group containing a carbonyl group; each p independently represents an integer of 1 to 3; Q 2 represents a single bond or an alkylene group; X 10 represents a hydrocarbon group of 1 to 30 carbon atoms which may have a substituent; Q 3 represents a single bond or a divalent linking group; Y 10 represents —C(═O)— or —SO 2 —; Y 11 represents an alkyl group of 1 to 10 carbon atoms which may have a substituent or a fluorinated alkyl group of 1 to 10 carbon atoms which may have a substituent; A − represents a carboanion; Y 12 represents a cyclic alkyl group of 4 to 20 carbon atoms which may have an oxygen atom (═O) as a substituent; and q represents 0 or 1.