Patent ID: 7960494

Claim:
A copolymer for semiconductor lithography, comprising: at least one repeating unit selected from among (A) a repeating unit having a hydroxyl group; (B) a repeating unit having a structure in which a hydroxyl group is protected by a group which inhibits dissolution in an alkaline developer and which dissociates by the action of an acid; (C) a repeating unit having a lactone structure; and (D) a repeating unit having a cyclic ether structure, wherein, when a solution of the copolymer in propylene glycol monomethyl ether acetate having a viscosity of 15 mPa·sec at 25° C. in PGMEA is caused to pass through a filter having a pore size of 0.03 μm under a pressure difference of 0.1 MPa for 60 minutes, the solution exhibits an average flow rate per unit filter area of 200 g/min/m 2 or more.