RESIN FOR RESIST, POSITIVE RESIST COMPOSITION, AND METHOD OF FORMING RESIST PATTERN

摘要

A positive resist composition which has excellent resolution and a wide focal-depth range; a resin for resists which is for use in the positive resist composition; and a method of forming a resist pattern from the positive resist composition. The resin for resists comprises, as main components, structural units (a) derived from an alpha-(lower alkyl)acrylic ester. The structural units (a) comprise: structural units (a1) derived from an alpha-(lower alkyl) acrylic ester having an acid-dissociable dissolution-inhibitive group; and lactone-containing monocyclic groups. The structural units (a1) comprise structural units represented by the following general formula (a1-1) [wherein R is hydrogen or lower alkyl; and R11 is an acid- dissociable dissolution-inhibitive group which contains a monocyclic aliphatic hydrocarbon group and contains no polycyclic aliphatic hydrocarbon groups].