OXOALKYL GROUP-CONTAINING SULFONIUM SALT COMPOUND, RESIST COMPOSITION AND METHOD FOR FORMING PATTERN USING THE COMPOSITION

摘要

PROBLEM TO BE SOLVED: To obtain a photoacid generator having high transparency to exposure light and excellent sensitivity in a photoresist composition for lithography using far-ultraviolet light with wavelength of >=130 nm and <=220 nm. SOLUTION: This photoresist composition uses a sulfonium salt compound of general formula (1) (R1 and R2 are each independently an oxo group- containing straight-chain, branched chain or monocyclic or bridged cyclic alkyl group; R3 is a straight-chain, a branched chain, monocyclic or bridged cyclic alkyl group; and Y- is a counter ion) as a photoacid generator.