AFM Nanopatterning of Transition Metal Oxide Thin Films

In this paper we show diverse methods for patterning transition metal oxide (TMO) thin films by Local Anodic Oxidation (LAO) using an Atomic Force Microscope (AFM). At first, direct lithography by current-controlled LAO of TMO thin films and selective wet etching is presented. For insulating films or those whose AFM patterns cannot be selectively removed by wet etching, fabrication of nanomasks is required; thus, the fabrication of Molybdenum and TMO nanomasks is reported. As a further development, we show the AFM fabrication of Mo/poly(methylmethacrylate) (PMMA) nanomasks through multistep processes combining LAO of Mo and dry etching of PMMA. Detailed discussions and comparisons between these methods are presented.