  Granular nanostructure of electron beam resist had limited the ultimate
resolution of electron beam lithography. We report a thermal process to achieve
a uniform and homogeneous amorphous thin film of poly methyl methacrylate
electron resist. This thermal process consists of a short time-high temperature
backing process in addition to precisely optimized development process
conditions. Using this novel process, we patterned arrays of holes in a metal
film with diameter smaller than 5nm. In addition, line edge roughness and
surface roughness of the resist reduced to 1nm and 100pm respectively.
