POLY(DIMETHYL-CO-DIPHENYLSILANE) AS A DEEP-UV AND AN OXYGEN PLASMA PORTABLE CONFORMABLE MASK

Abstract

Bi-layer resist processes for deep-UV and oxygen plasma are studied. Poly(dimethyl-co-diphenylsilane) is used as both deep-UV and oxygen plasma portable conformable masks because of its strong deep-UV and i-line (365 nm) absorption and its resistance to oxygen plasma. The bottom layer is P(MMA-PhPK), a copolymer of methylmethacrylate and 30 wt% of phenylpropenylketone, for the positive-tone pattern. P(MMA-PhPK) has greater deep-UV exposure sensitivity compared to PMMA. Good vertical sidewall profiles of lines of bottom layers are obtained.