Patent attributes
A positive resist composition of the present invention achieving significant performance improvements in high energy-beam lithography, which comprises a phenolic polymer having a property of being insoluble or hardly soluble in an aqueous alkali solution and becoming soluble in an aqueous alkali solution by the action of an acid, in which the phenolic polymer includes a repeating unit containing at least one selected from the group consisting of an acetal-protected phenolic hydroxyl group, a ketal-protected phenolic hydroxyl group, a tertiary ester-protected carboxyl group and a tetrahydropyranyl-protected carboxyl group; and a compound having a phenacylsulfonium structure and capable of generating an acid upon irradiation with one of actinic rays and radiation.
