Patent ID: 8206887

Claim:
A positive resist composition comprising a base material component (A) which exhibits increased alkali solubility under an action of an acid, and an acid generator component (B) which generates an acid upon exposure, wherein the base material component (A) contains a compound (A1) in which phenolic hydroxyl groups in a polyhydric phenol compound (a) containing two or more phenolic hydroxyl groups and having a molecular weight of 300 to 2,500 are protected with acid dissociable, dissolution inhibiting groups, wherein the average of the protection ratio of the compound (A1) is from 7 to 45 mol %, and the proportion of the compound (A1) in the component (A) is more than 80% by mass, the compound (A1) exhibits a standard deviation (σ n ) of the number of protective groups per molecule of less than 1, and the compound (A1) includes at least one acid dissociable, dissolution inhibiting group selected from the group consisting of an alkoxycarbonylalkyl group represented by general formula (p1) shown below and an alkoxyalkyl group represented by general formula (p2) shown below: (wherein R 1 represents a straight-chain, branched-chain, or a cyclic alkyl group, and may include a hetero atom in the structure; R 2 represents a cyclic alkyl group, and may include a hetero atom in the structure; and R 3 represents a hydrogen atom or a lower alkyl group; and n′ represents an integer from 1 to 3).