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, hav e been investigated for use in direct write and mask fabrication applicatio ns. The Sumitomo NEB-22A5 material has shown superior high resolution capab ilities with excellent exposure latitude for both isolated and line/space f eatures. 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 resis t has shown resolution down to 150 nm line/space features with excellent et ch selectivity and postexposure bake critical dimension control. Both resis ts perform well with respect to delay stability before and after exposure. This article will discuss the process development of the two resists and co mpare the performance characteristics including resolution, exposure latitu de, linearity, and etch selectivity in various chemistries. Effects relatin g to pre-exposure and postexposure bake delay will also be considered becau se of the susceptibility of many chemically amplified resists to contaminan ts in the air. Finally, the application of these resists for both direct wr ite and advanced mask making applications will be discussed. (C) 1998 Ameri can Vacuum Society. [S0734-211X(98)19006-6].