Radiosensitive linear components, patterning methods, polymers and onium salts

Abstract

The present invention aims to provide a radiosensitive linear composition, a patterning method, a polymer, and an onium salt that exhibit excellent sensitivity, CDU, LWR, MEEF, development defect suppression, and pattern rectangularity during pattern formation. A radiosensitive linear composition comprises: a polymer, a structural unit (I) having a partial structure derived from an onium salt containing the structure represented by formula (i), a structural unit (II) containing an acid-dissociable group; and a solvent. (In formula (i), X1- is S- or O-. X2 is S or O. S is included in at least one of the groups selected from X1- and X2. Z+ is a monovalent organic cation. * represents bonds with other atoms in the onium salt. The onium salt contains one or more polymerizable groups in portions other than the partial structure.)