Sub‐10 nm lithography and development properties of inorganic resist by scanning electron beam

We report the self‐developing properties of an AlF3‐doped LiF inorganic resist under irradiation by a scanning electron beam with an energy of 20–50 keV are reported. The self‐development properties strongly depended on both AlF3 concentration and film thickness. To explain this behavior, we presented an exposure model that takes into account a balance between a carbon contamination and a diffusion process. By optimizing resist qualities, we were able to delineate 5 nm linewidth patterns with 60 nm periodicity using a 30 kV electron beam.