Base material for pattern-forming material, positive resist composition and method of resist pattern formation

Abstract

A base material for a pattern-forming material, a positive resist composition, and a method of resist pattern formation that are capable of forming a high resolution pattern with reduced levels of LER. The base material includes a low molecular weight compound (X1), which is formed from a polyhydric phenol compound (x) that contains two or more phenolic hydroxyl groups and satisfies the conditions (1), (2), and (3) described below, wherein either a portion of, or all of, the phenolic hydroxyl groups are protected with acid dissociable, dissolution inhibiting groups: (1) a molecular weight within a range from 300 to 2,500, (2) a molecular weight dispersity of no more than 1.5, and (3) an ability to form an amorphous film using a spin coating method. Alternatively, the base material includes a protected material (Y1), which is formed from a polyhydric phenol compound (y) that contains two or more phenolic hydroxyl groups and has a molecular weight within a range from 300 to 2,500, in which a predetermined proportion of the phenolic hydroxyl groups are protected with acid dissociable, dissolution inhibiting groups.

Dependencies are inferred from the claim text.