Two-dimensional modeling of the self-limiting oxidation in silicon and tungsten nanowires

TL;DR

This paper develops a two-dimensional diffusion-based model for self-limiting oxidation in silicon and tungsten nanowires, incorporating stress effects and curvature, aligning well with experimental data.

Contribution

Introduces a novel 2D cylindrical oxidation model for nanowires that accounts for finite reactive regions and stress effects, advancing understanding of nanostructure oxidation.

Findings

Model accurately predicts oxidation behavior in nanowires.

Oxidation rate depends on curvature and temperature.

Model aligns with experimental data.

Abstract

Self-limiting oxidation of nanowires has been previously described as a reaction- or diffusion-controlled process. In this letter, the concept of finite reactive region is introduced into a diffusion-controlled model, based upon which a two-dimensional cylindrical kinetics model is developed for the oxidation of silicon nanowires and is extended for tungsten. In the model, diffusivity is affected by the expansive oxidation reaction induced stress. The dependency of the oxidation upon curvature and temperature is modeled. Good agreement between the model predictions and available experimental data is obtained. The developed model serves to quantify the oxidation in two-dimensional nanostructures and is expected to facilitate their fabrication via thermal oxidation techniques. https://doi.org/10.1016/j.taml.2016.08.002