Progress in EUV resist screening by interference lithography for high-NA lithography

The development of photoresists is crucial for the progress in lithographic technologies and integrated circuit altogether. For instance, the development of novel EUV resists is a critical enabler of future technology nodes, particularly towards the deployment of high-NA EUV lithography into high-volume manufacturing. Within the scope of a joint resist screening program between PSI and ASML, the development of EUV resists is investigated using EUV interference lithography. In this work, we provide a review of the recent progress in EUV resists by considering several resist platforms provided by different vendors. Lines/spaces patterning is extensively investigated as a function of film processing parameters. The challenge in developing resists is admittedly governed by a resolution-roughness-sensitivity (RLS) performance tradeoff, therefore performance results are presented with critical dimension (CD), dose-to-size (DtS), line-width-roughness (LWR) as well as the z-factor metric associated to the RLS tradeoff. We consider LS patterning between 16 and 13 nm half-pitch to identify materials matching current high-volume manufacturing specifications. We then investigate high-resolution resists for patterning down to 8 nm half-pitch, therefore potential candidates for high-NA EUVL. Further process optimization perspectives are finally discussed towards enabling future technology nodes.