Patent ID: 7358028

Claim:
A chemical amplification type positive photoresist composition comprising (A2) a resin made of a reaction product of (A1) an alkali soluble resin and (C1) a crosslinking polyvinyl ether compound wherein alkali solubility enhances by an action of an acid, and (B1) a photo acid generator generating acid under irradiation with radiation, wherein the component (A1) comprises a unit (a1′) derived from (α-methyl)hydroxystyrene represented by the following general formula (I′): wherein R represents a hydrogen atom or a methyl group and 1 represents an integer of 1 to 3, and an alkali-insoluble unit (a2′) having no acid dissociable dissolution inhibiting group, and wherein a dissolution rate of the component (A1) to an aqueous 2.38% by weight solution of TMAH (tetramethylammonium hydroxide) is from 10 to 100 nm/second, wherein the component (B1) is a poly(bissulfonyl)diazomethane photo acid generator.