Underlayer film-forming composition and pattern forming process

摘要

In lithography, a composition comprising a novolak resin comprising recurring units derived from a naphtholphthalein is used to form a photoresist underlayer film. The underlayer film is strippable in alkaline water, without causing damage to ion-implanted Si substrates or SiO2 substrates.

主权项

1. A photoresist underlayer film-forming composition for use in lithography, comprising a novolak resin comprising recurring units having the general formula (1) and a crosslinker:wherein R1 and R2 are independently hydrogen, an acid labile group, glycidyl group, or a straight, branched or cyclic C1-C10 alkyl, acyl or alkoxycarbonyl,
R3, R4 and R6 are independently hydrogen, or a straight, branched or cyclic C1-C10 alkyl, C2-C10 alkenyl, or C6-C10 aryl group, which may have a hydroxyl, alkoxy, acyloxy, ether or sulfide moiety, or a halogen atom, hydroxyl group or C1-C4 alkoxy group, R5 is hydrogen, or a straight, branched or cyclic C1-C6 alkyl, a straight, branched or cyclic C2-C10 alkenyl, or C6-C12 aryl group, which may have a hydroxyl, alkoxy, ether, thioether, carboxyl, alkoxycarbonyl, acyloxy, —COOR or —OR moiety, wherein R is a lactone ring, acid labile group, or -R′-COOR″, wherein R′ is a single bond or alkylene group, and R″ is an acid labile group, m, n, p, q and r each are 1 or 2.