Time-Dependent Electrical Contact Resistance at the Nanoscale

Abstract

Conductive-atomic force microscopy (C-AFM) and molecular dynamics (MD) simulations are used to investigate time-dependent electrical contact resistance (ECR) at the nanoscale. ECR is shown to decrease over time as measured using C-AFM and estimated using two approaches from MD simulations, although the experiments and simulations explore different time scales. The simulations show that time dependence of ECR is attributable to an increase in real contact area due to atoms diffusing into the contact. This diffusion-based aging is found to be a thermally activated process that depends on the local contact pressure. The results demonstrate that contact aging, previously identified as an important mechanism for friction, can significantly affect electrical conduction at the nanoscale. Graphical Abstract

A review of advances in tribology in 2020–2021

“…77(c)), based on which a friction model considering the effect of electronic properties fluctuation on potential energy corrugation during friction was proposed. Vazirisereshk et al [936] investigated nanoscale time-dependent electrical contact resistance (ECR) by combining conducting atomic force microscopy and MD simulations, and unraveled the important role of contact aging in interfacial electronic conduction. The contact aging will lead to the increase of actual contact area and the decrease of ECR, which is a thermally activated process and can be described by Arrhenius law.…”

A multi-resistance wide-range calibration sample for conductive probe atomic force microscopy measurements

“…C-AFM measurements are prone to environmental and experimental factors that heavily affect their stability, reproducibility, repeatability, and exactness [ 41 – 42 ]. The formation of a humidity-induced water meniscus at the tip–sample interface, the presence of surface contamination, and thermal drifts induce significant instabilities in C-AFM measurements [ 42 – 43 ].…”

“…C-AFM measurements are prone to environmental and experimental factors that heavily affect their stability, reproducibility, repeatability, and exactness [ 41 – 42 ]. The formation of a humidity-induced water meniscus at the tip–sample interface, the presence of surface contamination, and thermal drifts induce significant instabilities in C-AFM measurements [ 42 – 43 ]. Moreover, local overheating and anodic oxidation phenomena are commonly observed in C-AFM because of highly localized electric fields at the tip apex leading to structural damage considerably affecting the measurement reliability.…”