Patent ID: 7910282

Claim:
A copolymer for semiconductor lithography produced by a process comprising: copolymerizing a monomer having a hydroxyl group and a monomer having no hydroxyl group in a polymerization reaction solution comprising a polymerization solvent to produce the copolymer; and bringing the copolymer, which is present in the polymerization reaction solution, into contact with a poor solvent comprising: a polar solvent having a hydroxyl group; and a nonpolar solvent having no hydroxyl group, to reprecipitate or wash the copolymer, wherein a ratio of the amount of the poor solvent to a total amount of the polymerization reaction solution diluted with the polymerization solvent is 1-20:1, and wherein a molar composition of a hydroxyl group-containing repeating unit in a low molecular weight region corresponding to 5% of a copolymer total peak by gel permeation chromatography is within ±10% of an average molar composition of hydroxyl group-containing repeating units in a total of the copolymer.