Azide–novolak resin negative photoresist for <i>i</i>-line phase-shifting lithography

Abstract

A negative photoresist consisting of 4,4′-diazido-3,3′-dimethoxybiphenyl and a novolak resin, called micro resist for i-line (MRI), has been prepared and evaluated for i-line phase-shifting lithography. MRI has a high transmittance (80%/μm) and a high resist contrast (γ) at i line (365 nm). Line-and-space patterns of 0.30 μm were achieved using MRI in conjunction with an i-line phase-shifting lithography. The insolubilization mechanism of MRI is attributed to a secondary amine formed by the reaction of nitrene with novolak resin.