Planar nanotips as probes for transport experiments in molecules

Abstract

A reproducible technique to fabricate nanojunctions by combining electron beam lithography and lift-off process is reported. Brushing the poly(methyl methacrylate) (PMMA) layer for a precise short time t with a defocused electron-beam allows the fabrication of planar nanoelectrodes with inter-electrode distances in the range 10–200 nm, by applying a lift-off process after the exposure. Nanotips fabricated by electron beam lithography (EBL) are good probes for transport experiments on single molecules and molecular layers but the nanodevices have to be carefully designed, tested and managed, in order to avoid damage of nanoelectrodes and SiO 2 breakdown.