POSITIVE RESIST COMPOSITION AND METHOD OF FORMING RESIST PATTERN

摘要

A positive resist composition having a large exposure energy margin and excellent in resolution and dry etching resistance; and a method of forming a pattern from the positive resist composition. This resist composition comprises:a resin ingredient (A) which has acid-dissociable dissolution-inhibitive groups and comes to have enhanced alkali solubility by the action of an acid; and an acid generator ingredient (B) which generates an acid upon exposure to light. The resin ingredient (A) comprises: a structural unit (a1) represented by the following general formula (I); a structural unit (a2) represented by the general formula (I) wherein the hydroxy group has been protected by replacing the hydrogen atom thereof with an acid-dissociable dissolution-inhibitive group (II) represented by the following general formula (II); and a structural unit (a3) represented by the general formula (I) wherein the hydroxy group has been protected by replacing the hydrogen atom thereof with an acyclic acid-dissociable dissolution-inhibitive group (III).