New ArF Single-Layer Resist for 193-nm Lithography

Abstract

A new class of photoresist matrix polymer based on alicyclic cyclopolymer was developed for use in ArF single-layer lithography. A novel polymer was synthesized by terpolymerization reaction between tert-butyl methacrylate and alicyclic-malefic anhydride alternating copolymer, which has a hydroxy substituent on the alicyclic group. The polymer showed good adhesion property to Si- substrate and adequate dissolution behavior in a 2.38wt% TMAH aqueous solution, high thermal stability up to 180°C, and a good dry-etch resistance against CF₄ mixture gas (1.14 times the etching rate of novolak resist). Using an ArF excimer laser exposure system, a 140nm line and space patterns have been resolved.