Self-developing resist with submicrometer resolution and processing stability

Abstract

Nitrocellulose films have been shown to function as self-developing resist layers that are sensitive to both low-energy (<2 keV) Ar+ ions and to 193-nm UV radiation from pulsed excimer lasers. A resolution of <100 nm and aspect ratios >25:1 have been demonstrated using a stencil mask and an argon ion beam; the resolution obtained was mask limited. The sensitivity of the resist to 2-keV Ar+ ions is 36 μm/min at beam currents of 1 mA/cm2, allowing exposure times of 1 s for 0.5 μm of resist. The material is capable of functioning as a mask material for typical semiconductor dry etching processes.