Patent ID: 8110335

Claim:
A resist patterning process with a minimum line width or a minimum space width being 65 nanometers or less on a processing substrate, comprising (i) coating a chemically-amplified positive resist composition containing a base polymer on a processing substrate, (ii) removing an excess solvent component remained in the coated film by heating to obtain a resist film, (iii) pattern-exposing a high energy beam, and (iv) developing by using a developer, wherein the base polymer is a polymer comprising: at least one or more monomer unit represented by the following general formula (1), wherein the polymer always contains a unit with t being one or more: wherein R 1 represents a hydrogen atom or a methyl group; and R 2 represents a hydrocarbon, or an alkoxy hydrocarbon group having 1 to 6 carbon atoms, wherein t represents an integer of 0 to 2; and s represents an integer of 0 to 4, and 0<s+t≦5; a phenolic hydroxyl group is partly protected by an acid labile protecting group when t is one or two, and one or more monomer unit represented by the following general formula (2); wherein R 3 represents any of a hydroxyl group, a hydrocarbon, or an alkoxy hydrocarbon group having 1 to 6 carbon atoms, wherein u represents an integer of 0 to 4; and/or one or more monomer unit represented by the following general formula (3); wherein R 4 represents a hydroxyl group, a hydrocarbon, or an alkoxy hydrocarbon group having 1 to 6 carbon atoms wherein v represents an integer of 0 to 4, wherein the phenolic hydroxyl group in the monomer unit represented by the formula (1) is partly protected by the acid labile protecting group, wherein the sum of the monomers represented by the formulae (1) to (3) relative to total monomer units of the polymer is 95 mol % or more, the amount of monomers with t being one or more is 70 mol % or more relative to total monomer units of the formula (1) when two or more monomers represented by the formula (1) are contained, a sum of monomer units represented by the formulae (2) and (3) relative to total monomer units of the polymer is 5 to 30 mol %, and wherein a weight-average molecular weight of the polymer is 4,000 to 7,000.