Alkylsulfonium salts and photoresist compositions containing the same

摘要

A photoresist composition containing an alkylsulfonium salt compound represented by the following general formula (I): (I) wherein R1 and R2 may be the same or different, each being a linear, branched or cyclic C1 to C8 alkyl radical, R3 is a linear, branched or cyclic C1 to C8 alkyl radical, a C5 to C7 2-oxocycloalkyl radical, or a linear or branched C3 to C8 2-oxoalkyl radical, and Y- represents a counter ion. The photoresist composition has high transparency to deep U.V. light having wavelengths of 220 nm or less and is capable of forming good fine patterns with high sensitivity, thus being useful as chemically amplified type resist which is exposed to the deep U.V. light from an ArF excimer laser.