Patent ID: 8741537

Claim:
A positive resist composition, which comprises a resin having a structure showing a basicity and capable of increasing the solubility in an alkali developer by the action of an acid, and wherein the resin has the structure showing a basicity at a side chain, the resin has a lactone group, and the resin comprises a repeating unit having a partial structure containing an alicyclic hydrocarbon represented by formula (pI) or (pII): wherein Z represents an atomic group necessary to form an alicyclic hydrocarbon group with a carbon atom; R 11 represents a methyl group, an ethyl group, an n-propyl group, an isopropyl group, an n-butyl group, an isobutyl group or a sec-butyl group; R 12 , R 13 and R 14 each represents a straight chain or branched chain alkyl group having from 1 to 4 carbon atoms, or an alicyclic hydrocarbon group, provided that at least one of R 12 to R 14 represents an alicyclic hydrocarbon group; and wherein the resin comprises a repeating unit represented by formula (AI) as the repeating unit having the lactone group: wherein R b0 represents a hydrogen atom, a halogen atom, or an alkyl group having from 1 to 4 carbon atoms; A′ represents a single bond, an ether group, an ester group, a carbonyl group, an alkylene group, or a divalent linking group combining these groups; and B 2 represents a group represented by formula (Lc) or formula (III-1): wherein R a1 , R b1 , R c1 , R a1 and R e1 each represents a hydrogen atom or an alkyl group; m and n each represents an integer of from 0 to 3, and m+n is from 2 to 6; R 1b , R 2b , R 3b , R 4b , and R 5b each represents a hydrogen atom, an alkyl group, a cycloalkyl group, an alkoxyl group, an alkoxycarbonyl group, an alkylsulfonylimino group or an alkenyl group, and two of R 1b to R 5b may be bonded to form a ring.