Nano-lithography using a resist, patterned by electron exposure in an AFM configuration

We have used a metallised force microscope tip to apply a voltage and thereby expose a very thin resist film. It is possible to image the film surface before, during and after the exposure, without interference with the process. Uniform resist films as thin as 10 nm are fabricated using the Langmuir-Blodgett technique. To orient the defined pattern and to make electrical connections a special larger scale alignment structure is first defined by conventional electron beam lithography, either directly in the Langmuir-Blodgett resist film or in a complete first process with a separate resist system. The results from the one resist process gave conducting 50 nm lines in a 60 Å thick aluminium film after pattern transfer. The two step process, which is aiming towards definition of extremely small tunnel junctions for low temperature measurements, have produced similar conductive lines; still though, without tunnelling barriers between the two metal layers.