Abstract: A resist underlayer film-forming composition that exhibits a high etching resistance, a favorable dry etching rate ratio and optical constant, and can form a film exhibiting a good coatability even to a so-called uneven substrate, providing a small difference in film thickness after embedding, and having planarity and a superior hardness; a resist underlayer film formed from the resist underlayer film-forming composition; and a method of producing a semiconductor device.

Abstract: A step substrate coating composition for efficiently forming a coating that is capable of filling and flattening a pattern. A step substrate coating composition comprising a compound (A) of a main agent, a crosslinking agent, and a solvent, the compound (A) including a partial structure expressed by formula (A-1) (where the broken line represents bonding with an aromatic ring, the aromatic ring forming a polymer skeleton or a monomer, and n represents an integer of 1-4).

Abstract: A resist underlayer film forming composition contains a reaction product of an aromatic compound (A) having 6 to 60 carbon atoms and a compound represented by formula (B), and a solvent. (In the formula, X represent an oxygen atom or a nitrogen atom; Y represents a single bond, an oxygen atom or a nitrogen atom; X and Y may combine with each other to form a ring; and each of R1, R2, R3 and R4 independently represents a hydrogen atom, an alkyl group having 1 to 20 carbon atoms, a cyclic alkyl group having 3 to 8 carbon atoms or an aromatic group having 6 to 10 carbon atoms; provided that R2 is present only in cases where X is a nitrogen atom, and R4 is present only in cases where Y is a nitrogen atom.