Patent ID: 7687219

Claim:
A positive resist composition comprising: (A) a resin that contains a repeating unit (A1) having a lactone structure and a cyano group directly attached to the lactone structure, and increases its solubility to an alkali developer by action of an acid; (B) a compound that generates an acid by irradiation with actinic ray or radiation; and (C) a solvent, wherein the repeating unit (A1) is a repeating unit having a structure represented by general formula (A2) in any of a main chain and a side chain of the repeating unit (A1), wherein R 1 to R 6 each independently represents a hydrogen atom or a substituent, provided that at least one of R 1 to R 6 represents a cyano group, and at least two of R 1 to R 6 may be bonded with each other to form a ring structure, the structure represented by general formula (A2) being in any of a main chain and a side chain of the repeating unit (A1) using at least one of the positions that can be a hydrogen atom as R 1 to R 6 or a hydrogen atom in the substituents as R 1 to R 6 as a bond; and wherein resin (A), (1) contains a repeating unit having an alicyclic hydrocarbon structure substituted with a polar group, (2) does not contain a silicon atom, and (3) does not contain an aromatic group.