Composition for forming photoresist lower layer film

Abstract

This invention provides a composition for forming a photoresist underlayer film that improves sensitivity while forming a good photoresist pattern. The composition for forming a photoresist underlayer film of this invention comprises: a polymer (A) and a solvent; the polymer (A) is a monovalent organic group (B1) bonded to a polymer (C) via an aminocarbamate bond; the aminocarbamate bond is obtained by reacting a hydroxyl group in the polymer (C) having a side chain containing one or more polymerizable multiple bonds selected from the group consisting of carbon-carbon double bonds, carbon-carbon triple bonds, carbon-nitrogen double bonds, and carbon-nitrogen triple bonds, and having a hydroxyl group, with an isocyanate group in the compound (B) having an isocyanate group and the aforementioned monovalent organic group (B1).