Patent ID: 11650505

Abstract:
A resist underlayer film for lithography has high solubility in a resist solvent (solvent used in lithography) for expressing good coating film forming property and a smaller selection ratio of dry etching rate as compared with a resist. A resist underlayer film-forming composition containing a novolac resin containing a structure (C) obtained by a reaction of an aromatic ring of an aromatic compound (A) with a hydroxy group-containing aromatic methylol compound (B). The aromatic compound (A) may be a component constituting the structure (C) in the novolac resin. The hydroxy group-containing aromatic methylol compound (B) may be a compound of Formula (1):The hydroxy group-containing aromatic methylol compound (B) may be 2-hydroxybenzyl alcohol, 4-hydroxybenzyl alcohol, or 2,6-di-tert-butyl-4-hydroxymethyl phenol.