Effect of Mechanical Load on Atomic-Scale Fabrication Based on Local Anodic Oxidation

Abstract Atomic force microscopy (AFM)-based local anodic oxidation (LAO) stands out for its high resolution, maskless operation, and simplicity. However, the role of mechanical force in LAO remains underexplored. This study addresses this gap by introducing an innovative experimental approach that decouples mechanical load from other variables, enabling precise control of adhesive and compressive forces during LAO. Through systematic experiments, we investigate the effect of load conditions on oxide morphology and current–voltage characteristics. Results reveal that adhesive forces promote vertical oxide growth with minimal lateral spreading, while compressive forces enhance lateral oxidation but introduce considerable variability. A high compressive force (+ 20 nN) combined with high bias voltages (> 7 V) results in considerable current fluctuations and abrupt oxide protrusions, which are attributed to localized microdischarges and mechanical disruptions. These findings provide new insights into the interplay between mechanical forces and electrochemical processes in LAO, contributing to the development of more reliable and precise nanofabrication techniques. This study not only bridges a critical knowledge gap but also offers practical implications for optimizing AFM-based oxidation processes in semiconductor manufacturing and related fields. Graphical abstract