Abstract: Provided are a positive resist composition and a resist pattern forming method having fewer defects and superior lithographic characteristics. The positive resist composition includes a resin component (A) which has on a main chain a structural unit derived from an (?-lower alkyl)acrylate ester and exhibits increased alkali solubility under the action of an acid, and an acid generating component (B) which generates the acid upon irradiation with radiation, in which the resin component (A) is a copolymer having at least two structural units which is obtained by incorporating an acid when polymerizing at least one monomer for the production thereof.

Abstract: A method of forming a positive resist composition of the present invention includes a step (I) of passing a positive resist composition, which is obtained by dissolving a resin component (A) that displays increased alkali solubility under the action of acid and an acid generator component (B) that generates acid upon exposure in an organic solvent (S), through a filter (f1) equipped with a nylon membrane, wherein the resin component (A) is a copolymer containing at least two structural units obtained by polymerizing at least one monomer in the presence of acid. According to the present invention, it is possible to provide a method of producing a positive resist composition, a positive resist composition, and a method of forming a resist pattern that are capable of forming a resist pattern with reduced levels of both bridge-type defects and reprecipitation-type defects.

Abstract: A copolymer for semiconductor lithography, comprising at least a recurring unit (A) having a carboxylic acid ester structure whose solubility in alkali increases by the action of an acid and a carboxyl group-containing recurring unit (B), which copolymer is obtained via a step (P) of (co)polymerizing at least a monomer giving a recurring unit (A) and a step (Q) of forming a recurring unit (B) in the co-presence of a recurring unit (A)-containing (co)polymer and/or a monomer giving a recurring unit (A), and an acid. The copolymer is used in production of semiconductor as a resist polymer which is small in roughness, little in development defect and superior in lithography properties such as DOF and the like.

Abstract: Provided are a positive resist composition and a resist pattern forming method having fewer defects and superior lithographic characteristics. The positive resist composition includes a resin component (A) which has on a main chain a structural unit derived from an (?-lower alkyl)acrylate ester and exhibits increased alkali solubility under the action of an acid, and an acid generating component (B) which generates the acid upon irradiation with radiation, in which the resin component (A) is a copolymer having at least two structural units which is obtained by incorporating an acid when polymerizing at least one monomer for the production thereof.

Abstract: A method of forming a positive resist composition of the present invention includes a step (I) of passing a positive resist composition, which is obtained by dissolving a resin component (A) that displays increased alkali solubility under the action of acid and an acid generator component (B) that generates acid upon exposure in an organic solvent (S), through a filter (f1) equipped with a nylon membrane, wherein the resin component (A) is a copolymer containing at least two structural units obtained by polymerizing at least one monomer in the presence of acid. According to the present invention, it is possible to provide a method of producing a positive resist composition, a positive resist composition, and a method of forming a resist pattern that are capable of forming a resist pattern with reduced levels of both bridge-type defects and reprecipitation-type defects.

Abstract: A copolymer for semiconductor lithography, comprising at least a recurring unit (A) having a carboxylic acid ester structure whose solubility in alkali increases by the action of an acid and a carboxyl group-containing recurring unit (B), which copolymer is obtained via a step (P) of (co)polymerizing at least a monomer giving a recurring unit (A) and a step (Q) of forming a recurring unit (B) in the co-presence of a recurring unit (A)-containing (co)polymer and/or a monomer giving a recurring unit (A), and an acid. The copolymer is used in production of semiconductor as a resist polymer which is small in roughness, little in development defect and superior in lithography properties such as DOF and the like.