P(SI‐MA)/2‐Nitrobenzyl Cholate: A Two‐Level, Solution‐Inhibition, Deep‐UV Resist System

Abstract

Trimethylsilylmethyl methacrylate (SI) and methacrylic acid (MA) copolymerize with reactivity ratios of about one to give a material that has adequate aqueous‐base‐solubility and oxygen‐RIE resistance to serve as the top component of a bilevel resist system. A resin with a SI:MA ratio of 1.1:1 etches between and slower than hard‐baked HPR‐204, depending on the oxygen pressure in the reactor. Incorporation into P(SI:MA) of 20 w/o dinitrobenzyl cholate as a solution inhibitor results in a resist system that is capable of submicron resolution with a sensitivity of ∼0.2 J/cm². Oxygen‐RIE pattern transfer into thick planarizing HPR‐204 is readily accomplished.