A broad range of materials and processing techniques amenable to producing resist systems for ion beam lithography are discussed. The effect of random fluctuations in exposure dose on feature size for a gaussian beam of constant shape is calculated. The results of Monte Carlo simulations of exposures of PMMA on silicon by 50 KeV H2+, 100 KeV and and 150 KeV Li+ ions are presented and it is shown that feature resolution is fundamentally limited by the physical processes through which energy is deposited.
"Resist Possibilities And Limitations In Ion Beam Lithography", Proc. SPIE 0333, Submicron Lithography I, (30 June 1982); doi: 10.1117/12.933426; https://doi.org/10.1117/12.933426