Positive resist compositions and patterning process

摘要

A positive resist composition comprises (A) a resin component which becomes soluble in an alkaline developer under the action of an acid and (B) an acid generator. The resin (A) is a polymer comprising specific recurring units. The acid generator (B) is a specific sulfonium salt compound. When processed by lithography, the composition is improved in resolution, and forms a pattern with a minimal line edge roughness.