SULFONIUM SALT, RESIST COMPOSITION, AND PATTERNING PROCESS

摘要

A sulfonium salt of a naphthyltetrahydrothiophenium cation having a fluoroalkoxy chain with a specific anion is provided. The sulfonium salt is used as a photoacid generator to form a resist composition which when processed by immersion lithography, offers advantages of restrained dissolution in the immersion water and less pattern dependence or dark/bright bias.