Silicon-containing euv resist underlayer film forming composition

A resist underlayer film forming composition for EUV lithography, comprising:

• as a silane, a hydrolyzable silane, a hydrolyzate of the hydrolyzable silane, a hydrolysis condensate of the hydrolyzable silane, or a mixture of any of the hydrolyzable silane, the hydrolyzate, and the hydrolysis condensate, wherein
• the hydrolyzable silane includes a combination of tetramethoxysilane, an alkyltrimethoxysilane, and an aryltrialkoxysilane, and
• the aryltrialkoxysilane is represented by formula (1):
• (R2)n2—R1—(CH2)n1—Si(X)3 Formula (1)
• (in formula (1), R1 is an aromatic ring consisting of a benzene ring or a naphthalene ring or a ring including an isocyanuric acid structure, R2 is a substituent replacing a hydrogen atom on the aromatic ring and is a halogen atom or a C1-10 alkoxy group, and X is a C1-10 alkoxy group, a C2-10 acyloxy group, or a halogen group;
• and n1 is an integer of 0 or 1, and n2 is an integer of 1 to 5 for the benzene ring or an integer of 1 to 9 for the naphthalene ring).