Resist underlayer film-forming composition, resist underlayer film, resist underlayer film-forming process, and production method of patterned substrate

A production method of a patterned substrate comprising:

• applying a resist underlayer film-forming composition on a patterned substrate to obtain a coating film on the patterned substrate;
• heating the coating film to obtain a resist underlayer film;
• forming a resist pattern on an upper face side of the resist underlayer film;
• and
• etching the resist underlayer film and the substrate using the resist pattern as a mask,
• the resist underlayer film-forming composition comprising:
• a solvent;
• and
• a compound comprising an aromatic ring,
• wherein the solvent comprises:
• a first solvent having a normal boiling point of less than 156° C., and being an alkylene glycol monoalkyl ether, an alkylene glycol monoalkyl ether acetate, or a combination thereof;
• and
• a second solvent having a normal boiling point of no less than 210° C. and no greater than 230° C.,
• wherein the compound comprising an aromatic ring comprises a novolak resin, a resol resin, a styrene resin, an acenaphthylene resin, an indene resin, an arylene resin, a triazine resin, a calixarene resin, a fullerene resin, or a combination thereof.