ADDITIVE FOR COMPOSITION FOR FORMING RESIST UNDERLAYER FILM AND COMPOSITION FOR FORMING RESIST UNDERLAYER FILM COMPRISING THE SAME

摘要

Provided is an additive for a composition for forming a resist underlayer film with which footing of the resist pattern formed on the resist underlayer film is prevented. The additive comprises a copolymer having at least structural units V and W represented by formula (1) (1) (where L is a bond group that forms part of the polymer chain; M is a direct bond or linking group that contains at least one selected from -C(=O)-, -CH2-, and -O-; Q is an alkyl group wherein at least one of the hydrogen atoms is optionally substituted by a fluorine atom; at least one of L, M, and Q contains fluorine atoms; and R1 is an acetyl group, alkoxyalkyl group, tertiary alkyl group, or hydrogen atom).