Patent ID: 10844167

Abstract:
A composition for forming a resist underlayer film that has a high dry etching rate, functions as an anti-reflective coating during exposure, and fills a recess having a narrow space and a high aspect ratio. A composition for forming a resist underlayer film has a copolymer having a structural unit of following formula (1), a cross-linkable compound, a cross-linking catalyst, and a solvent: wherein R1 and R2 are each independently a C1-3 alkylene group or a single bond, Z is an —O— group, a —S— group, or a —S—S— group, and Ar is an arylene group. The copolymer is synthesized by a reaction of a carboxyl group of a dicarboxylic acid compound having an —O— group, a —S— group, or a —S—S— group with an epoxy group of a diglycidyl ether compound having an arylene group.