Patent ID: 7122589

Claim:
A positive resist composition comprising: (A) a resin comprising a repeating unit represented by the following formula (Ia) and a repeating unit represented by the following formula (Ib), which increases the solubility in an alkali developing solution by the action of an acid: (B) a compound represented by the following formula (I), (II) or (III): wherein Ra 1 each independently represents a hydrogen atom or an alkyl group, and A each independently represents a linkage group, Ra 11 represents an alkyl group containing 1 to 4 carbon atoms, Z represents a group of atoms forming an alicyclic hydrocarbon group together with the carbon atom adjacent to Ra 11 , Ra 12 to Ra 14 each independently represents a hydrocarbon group, with the proviso that at least one among Ra 12 , Ra 13 and Ra 14 represents an alicyclic hydrocarbon group: wherein R 1 to R 3 , which may be the same or different, each represents a hydrogen atom, an alkyl group, an alkenyl group, an aryl group or an alkoxy group, R 4 and R 5 , which may be the same or different, each represent a hydrogen atom, a cyano group, an alkyl group, an aryl group or an alkoxy group, Y 1 and Y 2 , which may be the same or different, each represents an alkyl group, an aryl group, an aralkyl group or a hetero atom-containing aromatic group, n represents an integer of 1 to 4, and with the proviso that when n is 2 or more, a plurality of R 1 s may be the same or different and a plurality of R 2 s may also be the same or different, any two or more among R 1 to R 3 , R 4 , R 5 , Y 1 and Y 2 may be bonded with each other to form a cyclic structure, two or more of structures represented by formula (I) or (II) may be present by being bonded to each other via one or more of a linkage group at any sites of R 1 s, R 2 s, R 3 S, R 4 s, R 5 s, Y 1 s and Y 2 s, X − represents a non-nucleophilic anion: wherein Ar represents an aryl group or a hetero atom-containing aromatic group, R 6 represents a hydrogen atom, a cyano group, an alkyl group or an aryl group, R 7 represents an alkyl group or an aryl group, Y 3 and Y 4 , which may be the same or different, each represents an alkyl group, an aryl group, an aralkyl group or a hetero atom-containing aromatic group, or Y 3 and Y 4 may be bonded with each other to form a ring, Ar and at least either Y 3 or Y 4 may be bonded with each other to form a ring, Ar and R 6 may be bonded with each other to form a ring, or two or more of structures represented by formula (III) may be present by being bonded to each other via one or more of a linkage group at Ar sites, either R 6 or R 7 sites, or either Y 3 or Y 4 sites, and X − represents a non-nucleophilic anion, and wherein the content of the compound represented by the formula (I) or (II) is from 0.1 to 20% by weight based on the content of the solids in the composition.