Patent ID: 8685615

Claim:
A resist underlayer film forming composition used in a lithography process comprising: a polymer (A) containing a unit structure having a hydroxy group, a unit structure having a carboxy group, or combination thereof; a crosslinkable compound (B) having at least two vinyl ether groups; a photoacid generator (C); a C 4-20 fluoroalkylcarboxylic acid or a salt of the fluoroalkylcarboxylic acid (D); and a solvent (E), wherein: the polymer (A) includes a unit structure selected from unit structures of Formula (1), Formula (2), and Formula (3): (where R 1 , R 2 , and R 3 are individually a hydrogen atom or a methyl group; X 1 , X 2 , and X 3 are individually a direct bond or a linking group; and Y is a light absorbing group), where when the total number of all unit structures constituting the polymer is assumed to be 1.0, the number a of unit structures of Formula (1), the number b of unit structures of Formula (2), and the number c of unit structures of Formula (3) satisfy equations: 0â‰¦aâ‰¦1.0, 0â‰¦bâ‰¦1.0, 0â‰¦câ‰¦0.5, and 0.5â‰¦a+bâ‰¦1.0, and has a weight average molecular weight of 3,000 to 100,000; and the C 4-20 fluoroalkylcarboxylic acid or a salt of the fluoroalkylcarboxylic acid (D) is a compound of Formula (6): R 7 â€”COO âˆ’ Z + Formula (6) (where R 7 is a C 4-20 fluoroalkyl group or a C 4-20 perfluoroalkyl group; and Z + is a proton, sulfonium, iodonium, ammonium, phosphonium, or stibonium).