Resist underlayer film-forming composition comprising epoxy adduct having long-chain alkyl group

A resist underlayer film-forming composition for covering a stepped substrate comprising

• an epoxy adduct (C), and
• an acid or an acid generator,
• wherein the epoxy adduct (C) is obtained by reacting an epoxy group-containing compound (A) having four epoxy groups with an epoxy adduct-forming compound (B) having an epoxy addition reactive group, wherein one or both of the epoxy group-containing compound (A) and the epoxy adduct-forming compound (B) contain an optionally branched alkyl group having a carbon atom number of three or more,
• wherein the epoxy group-containing compound (A) is a compound having a structure of formula (1):
• wherein PA comprises a compound and the
• of the structure of formula (1) is a unit structure, and wherein PA does not comprise a polymer,
• wherein the compound of PA comprises an aliphatic or aromatic hydrocarbon,
• wherein the aliphatic or aromatic hydrocarbon optionally comprises an oxygen atom, a nitrogen atom, or a combination thereof,
• Ep is a group of formula 1A or 1B:
• wherein a dotted line is a bond,
• n1 is 1, n2 and n3 are each an integer of 0 or 1, and n4 is 4,
• wherein the epoxy adduct-forming compound (B) is at least one compound selected from the group consisting of carboxylic acid (B1), carboxylic anhydride (B2), a phenol compound (B3), a hydroxyl group-containing compound (B4), a thiol compound (B5), an amino compound (B6), and an imide compound (B7), wherein
• the carboxylic acid (B1) is a compound of formula (2):
• wherein R1 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar1 is a C6-40 arylene group optionally having a substituent, n5 and n6 are each an integer of 0 or 1, n7 is an integer of 1, and n8 is an integer of 1 or 2,
• the carboxylic anhydride (B2) is a compound of formula (3):
• wherein Aa is an acid anhydride group, R2 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar2 is a C6-40 arylene group optionally having a substituent, n9 and n10 are each an integer of 0 or 1, and n11 is an integer of 1;
• the phenol compound (B3) is a compound of formula (4):
• wherein R3 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar3 is a C6-40 arylene group optionally having a substituent, n12 is an integer of 0 or 1, n13 is an integer of 1, n14 is an integer of 1, and n15 is an integer of 1 to 3,
• the hydroxyl group-containing compound (B4) is a compound of formula (5):
• wherein R4 is an optionally branched alkyl group having a carbon atom number of 3 to 19, n16 is an integer of 1 to 3, and n17 is an integer of 1,
• the thiol compound (B5) is a compound of formula (6):
• wherein R5 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar4 is a C6-40 arylene group optionally having a substituent, n18 and n19 are each an integer of 0 or 1, n20 is an integer of 1, and n21 is an integer of 1 to 3,
• the amino compound (B6) is a compound of formula (7):
• wherein Ab is a primary amino group, a secondary amino group, or a tertiary amino group, R6 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar5 is a C6-40 arylene group optionally having a substituent, n22 and n23 are each an integer of 0 or 1, n24 is an integer of 1, and n25 is an integer of 1 to 3, and
• the imide compound (B7) is a compound of formula (8):
• wherein Ac is an imido group having active hydrogen, R7 is an optionally branched alkyl group having a carbon atom number of 3 to 19, Ar6 is a C6-40 arylene group optionally having a substituent, n26 and n27 are each an integer of 0 or 1, n28 is an integer of 1, and n29 is an integer of 1, and
• wherein the unit structure in formula (1) is such that the epoxy group-containing compound (A) is selected from the group consisting of a compound having a benzene ring with an epoxy group attached thereto.

A resist underlayer film-forming composition for covering a stepped substrate comprising

• an epoxy adduct (C), and
• an acid or an acid generator,
• wherein the epoxy adduct (C) is obtained by reacting an epoxy group-containing compound (A) having at least two epoxy groups with an epoxy adduct-forming compound (B) having an epoxy addition reactive group, wherein one or both of the epoxy group-containing compound (A) and the epoxy adduct-forming compound (B) contain an optionally branched alkyl group having a carbon atom number of three or more,
• wherein the epoxy group-containing compound (A) is a compound or polymer having a structure of formula (1):
• wherein PA comprises a compound or a polymer and the
• of the structure of formula (1) is a unit structure,
• wherein the compound of PA or the polymer of PA comprises an aliphatic or aromatic hydrocarbon,
• wherein the aliphatic or aromatic hydrocarbon optionally comprises an oxygen atom, a nitrogen atom, or a combination thereof,
• Ep is a group of formula 1A, 1B, or a polymer comprising a structure of formula 1A or 1B:
• wherein a dotted line is a bond,
• n1 is an integer of 1, n2 and n3 are each an integer of 0 or 1, and n4 is an integer of 1 to 100,
• wherein the unit structure in formula (1) is such that the epoxy group-containing compound (A) is selected from the group consisting of a compound having a benzene ring with an epoxy group attached thereto, an epoxy group-containing aliphatic polyether, an epoxy group-containing novolak polymer, a polyether of epoxy group-containing alicyclic hydrocarbon, and an epoxy group-containing polyester,
• wherein when the epoxy group-containing compound (A) is a polymer, a weight average molecular weight thereof is from 500 to 100,000,
• wherein the epoxy adduct-forming compound (B) is at least one compound selected from the group consisting of the following formulas (2-8) to (2-14):