Unconventional MBE Strategies from Computer Simulations for Optimized Growth Conditions

TL;DR

This paper uses kinetic Monte-Carlo simulations to explore how step edge diffusion and desorption influence Molecular Beam Epitaxy, proposing strategies to optimize growth conditions for different surface morphologies.

Contribution

It introduces two novel strategies for optimizing MBE growth by leveraging desorption and step edge diffusion in different growth regimes.

Findings

Desorption can be used to achieve smoother surfaces during layer-by-layer growth.

Short high flux pulses increase growth rate and promote layer-by-layer growth.

Controlled reduction of flux leads to fast coarsening and smooth step edges.

Abstract

We investigate the influence of step edge diffusion (SED) and desorption on Molecular Beam Epitaxy (MBE) using kinetic Monte-Carlo simulations of the solid-on-solid (SOS) model. Based on these investigations we propose two strategies to optimize MBE growth. The strategies are applicable in different growth regimes: During layer-by-layer growth one can exploit the presence of desorption in order to achieve smooth surfaces. By additional short high flux pulses of particles one can increase the growth rate and assist layer-by-layer growth. If, however, mounds are formed (non-layer-by-layer growth) the SED can be used to control size and shape of the three-dimensional structures. By controlled reduction of the flux with time we achieve a fast coarsening together with smooth step edges.