Nano-lithography by electron exposure using an Atomic Force Microscope

We have used a conductive Atomic Force Microscope (AFM) tip to expose a ver y 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 re sist films as thin as 10 nm were fabricated using the Langmuir-Blodgett tec hnique. 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 res ults from the one resist process gave conducting 50 nm lines with a 60 Angs trom 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. (C) 1999 Elsevier Science B.V. All rights reserved.