Ra and rb indicate substitutable c1 to c30 organic groups. 03/26/1520150087155Resist underlayer film-forming composition(where r1 is a hydrogen atom or a methyl group; each of r2 and r3 is independently a hydrogen atom or an organic group such as a hydrocarbon group, etc., the hydrocarbon group optionally has at least one of a hydroxy group and a methylthio group as substituent(s); r4 is a hydroge