Electron projection lithography: Progress on the electron column modules for SCALPEL High-Throughput/Alpha exposure tools

We report on the realization of the electron column modules for the SCALPEL HT/Alpha EPL systems, designed to demonstrate high wafer throughput at resolutions at and below 100 nm. We describe our highly modular setup of each electron optical component targeted at maximum flexibility and enabling a fast and smooth evolution towards higher throughput and resolution. By applying strict design and process rules we were able to set-up the complete production flow from the design, construction and manufacturing of the components of the ferrite/dielectric deflector based projection optics up to established qualification schemes within less than one year. Crucial for the overall tool performance is the timely availability of system alignment and metrology strategies. Here we adapt state of-the-art techniques from light optical lens manufacturing to a maximum amount. We discuss our metrology and alignment approach based on aerial image analysis combined with extensive electron optical imaging simulations and present first theoretical and experimental sub-100 mn results.