| abstract |
The invention relates to a resist underlayer film forming composition containing a resin containing a structural unit represented by formula (1): [in formula (1), R1 represents a thiadiazole group which is optionally substituted by a C1 to 6 alkyl group optionally interrupted by a carboxy group, a C1 to 6 alkyl group optionally substituted by a hydroxyl group, or a C1 to 4 alkylthio group, and R2 represents a hydrogen atom] or by the formula (2): [in formula (2), R1 is the same as defined above, and * represents a linking moiety)]. The resist underlayer film forming composition provides a backing underlayer film which exhibits excellent solvent resistance, excellent optical parameters, excellent dry etch rate, and excellent to incorporation. |