Sulfonium salts and chemically amplified positive resist compositions

Abstract

The invention provides a novel sulfonium salt having a substituted or unsubstituted arylsulfonate anion. The novel sulfonium salt minimizes the influence of deactivation by basic compounds not only at a resist surface, but also at a resist-substrate interface, assists a resist to be configured to a definite pattern profile. When the sulfonium salt has an acid labile group, it is effective for increasing the dissolution contrast between exposed and unexposed areas. The sulfonium salt is useful in a chemically amplified positive resist composition which lends itself to fine patterning and features high resolution.

Dependencies are inferred from the claim text.