The role of step edge diffusion in epitaxial crystal growth

TL;DR

This paper investigates how step edge diffusion influences the formation and scaling of structures during epitaxial growth, revealing transitions in surface morphology based on diffusion rates.

Contribution

It extends a simple cubic solid-on-solid model to analyze the effects of different step edge diffusion regimes on surface structure and scaling behavior.

Findings

Sharp transition from significant to intermediate SED effects.

Continuous transition as SED vanishes.

Control of surface features via flux and temperature variations.

Abstract

The role of step edge diffusion (SED) in epitaxial growth is investigated. To this end we revisit and extend a recently introduced simple cubic solid-on-solid model, which exhibits the formation and coarsening of pyramid or mound like structures. By comparing the limiting cases of absent, very fast (significant), and slow SED we demonstrate how the details of this process control both the shape of the emerging structures as well as the scaling behavior. We find a sharp transition from significant SED to intermediate values of SED, and a continuous one for vanishing SED. We argue that one should be able to control these features of the surface in experiments by variation of the flux and substrate temperature.