POSITIVE RESIST COMPOSITION AND METHOD FOR FORMATION OF RESIST PATTERNS

摘要

A positive resist composition capable of forming resist patterns which are reduced in LWR and have good shapes; and a method for the formation of resist patterns. A positive resist composition comprising a resin component (A) which can be enhanced in the solubility in alkali by the action of an acid and an acid generator component (B) which can generate an acid on light exposure, wherein the resin component (A) comprises structural units (a1) having acetal-type protective groups and the acid generator component (B) contains an acid generator (B1) having a cation moiety represented by the general formula (b-5): [Chemical formula 1] (b-5) wherein R^a and R^b are each independently alkyl, alkoxy, halogeno, or hydroxy; R^c is optionally substituted aryl or alkyl; and n' and n" are each independently an integer of 0 to 3.