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, represented by formula (1). 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 satisfactory mask fidelity and a minimal LER. Herein R 1 is H or methyl, m is 1 or 2, and n is 1 or 2.