A new scenario in probe local oxidation: Transient pressure-wave-assisted ionic spreading and oxide pattern formation

Abstract

A new mechanism of shock-wave-assisted OH- ionic spreading in AFM anodic oxidation which is at work under relatively high tip biases, high tip currents, and high humidity conditions is reported. This involves the transport of OH- reactants by transient shock-wave (SW) propagation. SW propagation can drastically influence the formation of oxide patterns by fully or partially extending the distribution of OH- oxidants. The ultrafast propagation of transient shock waves significantly extends the lateral distribution of the OH- reactant, leading to the formation of unique oxide patterns. A hydrodynamic simulation was performed to quantitatively describe the ionic- spreading mechanism in terms of shock pressure and propagation distance.