X-RAY LITHOGRAPHY FOR SUB-HALF-MICROMETER DEVICES

Abstract

Steeply profiled high-aspect-ratio Ta patterns for X-ray masks have been fabricated using low-temperature ECR plasma etching with SF₆ gas. Side etching of the Ta patterns was restrained without using any additional gas to form a sidewall protection polymeric film. This X-ray mask technology has been applied to sub-half-micrometer pattern fabrication using an X-ray lithography system based on a compact synchrotron. N-channel MOS transistors with 0.3-μm gates have been fabricated using the X-ray lithography for all four mask levels.