Non-contact Local Conductivity Measurement of Metallic Nanowires Based on Semi-near-field Reflection of Microwave Atomic Force Microscopy

Abstract

In this study, a non-contact and quantitative evaluation method was developed to measure the conductivity of metallic nanowires with a nanometer-scale spatial resolution. A coaxial probe was experimentally fabricated; using this probe, microwave images of the Al, Ag, and Cu nanowires and their topography images were simultaneously obtained via microwave atomic force microscopy (M-AFM) in the non-contact mode. A semi-near-field reflection model was established to describe the spatial distribution of a microwave between the tip of the probe and the sample. The local conductivities of metallic nanowires on the nanometer-scale can be quantitatively evaluated in a single scan, using a metal strip substrate to calibrate the reflection signal.