Patent ID: 7972762
Filing Date: 2011-07-05
Classification: C08F,G03F,Y10S

Abstract:
1. A positive resist composition comprising: a resin component (A) which has on a main chain a structural unit (a1) derived from an (α-lower alkyl)acrylate ester and exhibits increased alkali solubility under the action of an acid, and an acid generating component (B) which generates an acid upon irradiation with radiation, wherein the resin component (A) is a copolymer comprising, as the structural unit (a1), a structural unit (a11) derived from (α-lower alkyl)acrylate ester which has acid dissociable dissolution inhibiting groups, a structural unit (a12) derived from (α-lower alkyl)acrylate ester which includes a lactone-containing monocyclic or polycyclic group, and a structural unit (a13) derived from an (α-alkyl)acrylate ester that contains a polar group-containing aliphatic hydrocarbon group, and a structural unit which is different from the structural unit (a1), is obtained by incorporating sulfuric acid or trifluoroacetic acid when polymerizing an (α-lower alkyl) acrylate ester monomer, has the structure of an (α-lower alkyl) acrylic acid, and is derived from the structural unit (a1) or the (α-lower alkyl) acrylate ester monomer, wherein the sulfuric acid or trifluoroacetic acid reacts on a portion of the (α-lower alkyl) acrylate ester monomer before polymerization and/or a part of the structural unit (a1) in the polymer generated by polymerizing the monomer and dissociates the acrylate ester terminal.