Radiosensitive linear composition, intermediate composition of radiosensitive linear composition, and method for forming resist pattern

Abstract

This invention provides a radiosensitive linear composition that, while ensuring storage stability, exhibits high sensitivity to radiation and good CDU performance. The radiosensitive linear composition of this invention contains a resin (A) containing an acid-dissociable group and an acid additive (C). The resin (A) containing the acid-dissociable group satisfies one or more of requirements 1A and 1B, and the acid additive (C) satisfies at least one of requirements c1 and c2, has a pKa of 2.8 or less, and a boiling point or decomposition temperature of 160°C or more. Requirements 1A: The resin (A) containing the acid-dissociable group further comprises a structural unit derived from a radiosensitive linear ononium salt (B) having a specific monazonium cation. Requirements 1B: It further comprises a radiosensitive linear ononium salt (B) as a non-polymer having a specific monazonium cation. Requirements c1: It has two or more groups selected from the group consisting of -COOH, -OH, and -NHR. Requirements c2: It has a phosphonic acid group.