RESIST-UNDERLAYER-FILM-FORMING COMPOSITION USED IN MULTILAYER RESIST PROCESS, RESIST UNDERLAYER FILM, METHOD FOR FORMING SAME, AND PATTERN-FORMATION METHOD

摘要

A composition for forming a resist underlayer film includes a polymer having a structural unit represented by a formula (1). Ar1, Ar2, Ar3 and Ar4 each independently represent a divalent aromatic hydrocarbon group or a divalent heteroaromatic group. A part or all of hydrogen atoms included in the divalent aromatic hydrocarbon group and the divalent heteroaromatic group represented by Ar1, Ar2, Ar3 or Ar4 may be substituted. R1 represents a single bond or a divalent hydrocarbon group having 1 to 20 carbon atoms. A part or all of hydrogen atoms included in the divalent hydrocarbon group represented by R1 may be substituted. The divalent hydrocarbon group represented by R1 may have an ester group, an ether group or a carbonyl group in a structure thereof. Y represents a carbonyl group or a sulfonyl group. m is 0 or 1. n is 0 or 1.