Atomic force microscope nanolithography of graphene: cuts, pseudo-cuts and tip current measurements

TL;DR

This study explores AFM nanolithography on graphene, revealing that actual cuts are not current-driven and demonstrating a reliable, high-resolution technique for fabricating and modifying graphene nanodevices.

Contribution

It provides new insights into the mechanisms of AFM nanolithography on graphene and demonstrates a precise, flexible method for graphene device fabrication.

Findings

Cuts are not driven by tip current.

Real cuts show a strong current reduction above a threshold voltage.

Achieved resolution down to 15 nm in graphene nanodevices.

Abstract

We investigate atomic force microscope nanolithography of single and bilayer graphene. In situ tip current measurements show that cutting of graphene is not current driven. Using a combination of transport measurements and scanning electron microscopy we show that, while indentations accompanied by tip current appear in the graphene lattice for a range of tip voltages, real cuts are characterized by a strong reduction of the tip current above a threshold voltage. The reliability and flexibility of the technique is demonstrated by the fabrication, measurement, modification and re-measurement of graphene nanodevices with resolution down to 15 nm.