Patent ID: 8211615

Claim:
A copolymer for immersion lithography, comprising: a repeating unit (A) that generates an alkali-soluble group by removing a protecting group through action of an acid, a repeating unit (B) having a lactone structure, and a repeating unit (C) that generates an alcoholic hydroxyl group by removing a protecting group through action of an acid, wherein, when a solution of the copolymer in propylene glycol monomethyl ether acetate is applied to a wafer and then heated to form a thin film, and a 15-μL droplet of pure water is added onto the thin film, the inclination of the wafer at the time when the water droplet starts to move is 35° or less, wherein the repeating unit (C) has a structure represented by formula (C2): wherein R 14 represents a hydrogen atom or a C1-C4 hydrocarbon group which may be substituted by a fluorine atom; R 15 to R 17 each represent a hydrogen atom, a hydroxyl group, or a substituent represented by formula (c1): wherein R 18 represents a C1-C15 hydrocarbon group; and at least one of R 15 to R 17 is a substituent represented by formula (c1).