| abstract |
A positive resist composition that ensures less defect, excelling in lithographic characteristics; and a method of forming a resist pattern therewith. There is provided a positive resist composition comprising resin component (A) having in its main chain a structural unit derived from an (α-lower alkyl)acrylic ester whose solubility in alkali is increased by the action of an acid and acid generator component (B) capable of generating an acid upon radiation exposure, wherein the resin component (A) is a copolymer having at least two types of constituent units obtained by in production through polymerization of at least one type of monomer, causing an acid to be present. |