High-Aspect-Ratio Nanometer-Pattern Fabrication Using Fullerene-Incorporated Nanocomposite Resists for Dry-Etching Application

Abstract

This paper presents the improved performance of a nanocomposite resist system that incorporates an unseparated mixture of fullerenes C₆₀ and C₇₀ into ZEP520, a positive electron-beam resist, particularly focusing on the enhancement of mechanical strength and dry-etching resistance. This system exhibits similar improvements to that of a pure C₆₀-incorporated system; 90-nm-pitch high-aspect-ratio (>5) resist patterns without pattern collapse and a 10-% enhancement of dry-etching resistance are obtained in a 10-wt% fullerene mixture-incorporated system due to the reinforcement effect induced by the fullerene incorporation. In addition, 80-nm-pitch resist patterns are successfully transferred to SiN film by C₂F₆-reactive ion etching without any harmful effects. The use of an unseparated mixture of C₆₀ and C₇₀, which is commercially available at a much lower price than pure C₆₀, will greatly facilitate the practical application of the nanocomposite resist system from the economic point of view.