Onium Salt, Resist Composition, And Patterning Process

Abstract

The present invention is an onium salt represented by the following general formula (1), where n1 represents an integer of 0 or 1; n2 represents an integer of 0 to 3; R1a represents a hydrocarbyl group having 1 to 20 carbon atoms and optionally containing a heteroatom; n3 represents an integer of 0 to 3; R1b represents a hydrocarbyl group having 1 to 36 carbon atoms and optionally containing a heteroatom; XA represents a carbonyl group that forms an amide bond together with an adjacent —NH or represents a sulfonyl group that forms a sulfonamide bond together with the adjacent —NH; n4 represents an integer of 1 or 2; and Z+ represents an onium cation. This provides: a resist composition in lithography that has high sensitivity and excellent resolution, can improve LWR and CDU, and can also suppress collapse of a resist pattern; and a novel onium salt to be used in the resist composition.

Dependencies are inferred from the claim text.