Nonlinear evolution of surface morphology in InAs/AlAs superlattices via surface diffusion

TL;DR

This paper presents continuum simulations of surface morphology evolution in InAs/AlAs superlattices, showing that nonlinear elastic energy dependence is crucial for matching experimental data, and reveals that modulation amplitude is independent of surface diffusion constants.

Contribution

It introduces a nonlinear elastic energy model to accurately simulate surface morphology evolution in superlattices, validated by experimental data.

Findings

Simulation results match synchrotron x-ray diffraction experiments.

Nonlinear elastic energy dependence is essential for modeling.

Modulation amplitude is independent of surface diffusion constants.

Abstract

Continuum simulations of self-organized lateral compositional modulation growth in InAs/AlAs short-period superlattices on InP substrate are presented. Results of the simulations correspond quantitatively to the results of synchrotron x-ray diffraction experiments. The time evolution of the compositional modulation during epitaxial growth can be explained only including a nonlinear dependence of the elastic energy of the growing epitaxial layer on its thickness. From the fit of the experimental data to the growth simulations we have determined the parameters of this nonlinear dependence. It was found that the modulation amplitude don't depend on the values of the surface diffusion constants of particular elements.