Toward 10 nm half-pitch in extreme ultraviolet lithography: results on resist screening and pattern collapse mitigation techniques

摘要

Extreme ultraviolet (EUV) lithography is considered to be the most promising option to continue with the downscaling of integrated circuits in high-volume manufacturing. One of the main challenges, however, is the development of EUV resists that fulfill the strict sensitivity, resolution, and line-edge roughness specifications of future nodes. Here, we present our EUV resist screening results of a wide range of EUV resists in their developmental phase from our collaborators from around the world. Furthermore, we have carried out extensive experiments to improve the processing parameters of the resists as well as to identify the optimal wafer pretreat-ment methods in order to optimize the adhesion of the resist to the substrate. We show that even though significant improvements in performance of chemically amplified resists have been achieved, pattern collapse is still the major process-limiting factor as the resolution decreases below 14 nm half-pitch. extreme ultraviolet lithography; interference lithography; photoresist; chemically amplified resist; chemically amplified resist; resolution, line-edge roughness, sensitivity trade-off; line-edge roughness; pattern collapse