Sub-10 nm lithography and development properties of inorganic resist by scanning electron beams

We report the self-developing properties of a AlF3-doped LiF inorganic resist under irradiation by a scanning electron beam with an energy of 50 keV. The self-development properties strongly depended on both AlF3 concentration and film thickness. The required dose to complete the development seemed to be proportional to the volume under the irradiation area. To explain this behavior, we presented an exposure model that takes into account a balance between a carbon contamination and a transfer process. By optimizing resist qualities, we were able to delineate 5 nm linewidth patterns with 60 nm periodicity using a 30 kV electron beam, and pattern transfer by liftoff was demonstrated. (C) 1995 American Vacuum Society.