AFM manipulation of gold nanowires to build electrical circuits

TL;DR

This paper presents SPANC, a novel AFM-based technique for fabricating and characterizing nanoscale gold nanowire circuits that are reconfigurable, cost-effective, and capable of contacting extremely small nano-objects.

Contribution

Introduction of SPANC, a new AFM-assisted method for creating nanocircuits with low contact resistance, reconfigurability, and without using polymers or chemicals.

Findings

Fabricated nanocircuits with contact resistance around 9 Ohms.

Achieved electrical contact with nano-objects as small as 10 nm.

First experimental measurement of sheet resistance of thin antimonene flakes.

Abstract

We introduce scanning-probe-assisted nanowire circuitry (SPANC) as a new method to fabricate electrodes for the characterization of electrical transport properties at the nanoscale. SPANC uses an atomic force microscope (AFM) to manipulate nanowires to create complex and highly conductive nanostructures (paths) that work as nanoelectrodes, allowing connectivity and electrical characterization of other nano-objects. The paths are formed by the spontaneous cold welding of gold nanowires upon mechanical contact, leading to an excellent contact resistance of about 9 Ohms/junction. SPANC is an easy to use and cost-effective technique that fabricates clean nanodevices. Hence, this new method can complement and/or be an alternative to other well-established methods to fabricate nanocircuits such as electron beam lithography (EBL). The circuits made by SPANC are easily reconfigurable, and their fabrication does not require the use of polymers and chemicals. In this work, we present a few examples that illustrate the capabilities of this method, allowing robust device fabrication and electrical characterization of several nano-objects with sizes down to aprox. 10 nm, well below the current smallest size able to be contacted in a device using the standard available technology (around 30 nm). Importantly, we also provide the first experimental determination of the sheet resistance of thin antimonene flakes.