Effects of acid generator anions on radiation-induced decomposition and dissolution kinetics of chemically amplified resists

Abstract

Chemically amplified resists (CARs) are widely used in lithography for manufacturing semiconductor devices. To reduce the occurrence of stochastic defects in CARs, increased acid generator concentration is required. In this study, we investigated the effects of acid generator anions on the radiation-induced decomposition of acid generators using electron pulse radiolysis and γ-radiolysis methods. Their effects on the dissolution dynamics of poly(4-hydroxystyrene) (PHS) films were also investigated using contact angle measurement and quartz crystal microbalance methods. Triphenylsulfonium trifluoromethanesulfonate, triphenylsulfonium nonafluoro-1-butanesulfonate, triphenylsulfonium 4-toluenesulfonate, and triphenylsulfonium salicylate, were used as acid generators or photodecomposable quenchers. The anions showed minimal effect on the decomposition of the acid generators and photodecomposable quenchers; however, they influenced the surface free energy, dissolution kinetics of the PHS films, and water penetration into the PHS films. In particular, the effect of salicylate on the dissolution kinetics of PHS films is significant.