Comparison of negative resists for 100 nm electron-beam direct write and mask making applications

A new negative tone, chemically amplified deep ultraviolet resist, Shipley UVN-2, and a negative electron-beam (e-beam) resist, Sumitomo NEB-22A5, have been investigated for use in direct write and mask fabrication applications. The Sumitomo NEB-22A5 material has shown superior high resolution capabilities with excellent exposure latitude for both isolated and line/space features. Line and space gratings and isolated lines of 100 nm were resolved in a 400 nm film of NEB-22 using a 40 kV e-beam exposure tool. UVN-2 resist has shown resolution down to 150 nm line/space features with excellent etch selectivity and postexposure bake critical dimension control. Both resists perform well with respect to delay stability before and after exposure. This article will discuss the process development of the two resists and compare the performance characteristics including resolution, exposure latitude, linearity, and etch selectivity in various chemistries. Effects relating to pre-exposure and postexposure bake delay will also be considered because of the susceptibility of many chemically amplified resists to contaminants in the air. Finally, the application of these resists for both direct write and advanced mask making applications will be discussed. (C) 1998 American Vacuum Society. [S0734-211X(98)19006-6].