Patent ID: 7955780

Claim:
A positive resist composition, comprising: (A) a resin capable of increasing solubility in an alkaline developer under action of an acid, wherein the resin (A) has a recurring unit having a first group selected from the groups represented by any of the following formulas (pI) to (pV), a recurring unit having a second group selected from the groups represented by any of the following formulas (pI) to (pV) but different from the first group, and a structure represented by the following formula (1) in a polymer main chain; (B) a compound generating an acid upon irradiation with actinic rays or radiation; and (C) a solvent: in the formulas (pI) to (pV), R 11 represents an alkyl group or a cycloalkyl group; Z represents an atomic group necessary to form a cycloalkyl group with the carbon atom; R 12 to R 16 each independently represents an alkyl group or a cycloalkyl group provided that at least one of R 12 to R 14 or either one of R 15 or R 16 represents a cycloalkyl group; R 17 to R 21 each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group provided that at least one of R 17 to R 21 represents a cycloalkyl group and either one of R 19 or R 21 represents an alkyl group or a cycloalkyl group; and R 22 to R 25 each independently represents a hydrogen atom, an alkyl group, or a cycloalkyl group provided that at least one of R 22 to R 25 represents a cycloalkyl group and R 23 and R 24 may be coupled together to form a ring, in the formula (1), L represents, when m=1, a single bond or a divalent hydrocarbon group which may have a heteroatom and L represents, when m≧2, an m+1 valent hydrocarbon group which may have a heteroatom; R 1 and R 2 each independently represents a group selected from the group consisting of alkylenes, cycloalkylenes, oxyalkylenes, arylenes, divalent thiazoline rings, divalent oxazoline rings, and divalent imidazoline rings or a divalent group formed using two or more thereof in combination; R 3 and R 4 each independently represents an alkyl group, a cycloalkyl group, an alkenyl group, or an aryl group and R 3 and R 4 may be coupled with a carbon atom of R 1 or L adjacent thereto to form a ring structure; n and k each independently stands for 0 or 1; and m stands for an integer of from 1 to 16.