Electron beam lithography - Resolution limits

Electron beam lithography is generally accepted to have the highest practical resolution capability. In this paper the state of the art in terms of resolution is reviewed. This covers conventional resists such as PMMA, contamination resist, inorganic resists and damage processes. Some insights into the resolution limiting factors are given although the precise limitations still remain unclear. Consideration is also given as to the best measure of resolution and it is suggested that the minimum line spacing is a more appropriate and less subjective measure than minimum achievable feature size.