Island, pit and groove formation in strained heteroepitaxy

TL;DR

This study investigates the morphological evolution of strained heteroepitaxial films using kinetic Monte Carlo simulations, revealing island, pit, and groove formations influenced by temperature and deposition conditions.

Contribution

It introduces a 3D kinetic Monte Carlo model with Green's function elastic calculations to analyze surface morphologies in heteroepitaxy, highlighting temperature-dependent island and pit formation mechanisms.

Findings

Isolated semi-spherical and conical islands form under certain deposition rates.

High-temperature annealing results in closely packed islands due to instability.

Low-temperature conditions lead to pit and groove formation via layer-by-layer nucleation.

Abstract

We study the morphological evolution of strained heteroepitaxial films using a kinetic Monte Carlo method in three dimensions. The elastic part of the problem uses a Green's function method. Isolated islands are observed under deposition conditions for deposition rates slow compared with intrinsic surface roughening rates. They are semi-spherical and truncated conical for high and low temperature cases respectively. Annealing of films at high temperature leads to the formation of closely packed islands consistent with an instability theory. At low temperature, pits form via a layer-by-layer nucleation mechanism and subsequently develop into grooves.