We have used a conductive Atomic Force Microscope (AFM) tip to expose a very thin resist film. An exposing current of low energy electrons was induced from the tip to the substrate by applying a small bias voltage. Uniform resist films as thin as 10 nm were fabricated using the Langmuir–Blodgett technique. To orient the defined pattern and to make electrical connections a special larger scale alignment structure was first defined by conventional electron beam lithography, either directly in the Langmuir–Blodgett resist film or in a separate first lift-off process with a thicker resist. The results from the one resist process gave conducting 50 nm lines with a 60 Å thick vacuum deposited aluminium film after the pattern transfer. The two step process, which is aiming towards definition of ultra small tunnel junctions, has produced similar conductive lines.
Davidsson, P., Lindell, A., Mäkelä, T., Paalanen, M., & Pekola, J. (1999). Nano-lithography by electron exposure using an Atomic Force Microscope. Microelectronic Engineering, 45(1), 1-8. https://doi.org/10.1016/S0167-9317(98)00255-X