Underlayer Designs to Enhance EUV Resist Performance

Abstract

Extreme ultraviolet (EUV) lithography has gained momentum as the method of choice for <32-nm half-pitch device fabrication. In this paper, we describe our initial efforts to increase the EUV resist's performance via introduction of a thermally crosslinkable underlayer. We have demonstrated the benefits of adding an EUV underlayer into the regular EUV litho stack and investigated the effect of underlayer film thickness, post-coat bake temperature, and adding other additives such as PAG and sensitizer on the overall litho performance of EUV resists.