Self-assembled island formation in heteroepitaxial growth

TL;DR

This paper explores how strain and kinetic mechanisms influence island formation during heteroepitaxial growth, revealing a self-assembly process driven by stress relaxation and atom detachment dynamics.

Contribution

It introduces an atomistic model that captures the strain-assisted kinetic processes leading to narrow island size distributions in heteroepitaxial growth.

Findings

High misfit induces narrow island size distribution.

Strain-assisted detachment and biased diffusion drive self-assembly.

Kinetic mechanisms are crucial for island formation.

Abstract

We investigate island formation during heteroepitaxial growth using an atomistic model that incorporates deposition, activated diffusion and stress relaxation. For high misfit the system naturally evolves into a state characterized by a narrow island size distribution. The simulations indicate the existence of a strain assisted kinetic mechanism responsible for the self-assembling process, involving enhanced detachment of atoms from the edge of large islands and biased adatom diffusion.