Kinetic Monte Carlo Simulation of Strained Heteroepitaxial Growth with Intermixing

TL;DR

This paper introduces an efficient kinetic Monte Carlo simulation method for strained heteroepitaxial growth with intermixing, capturing key growth phenomena and enabling the study of quantum dot formation.

Contribution

It presents a novel combination of multigrid and expanding box methods for elastic calculations within a rejection-reduced kinetic Monte Carlo framework, improving simulation efficiency.

Findings

Intermixing significantly affects strained film growth.

The method accurately simulates quantum dot self-assembly.

Elastic effects are effectively incorporated into the model.

Abstract

An efficient method for the simulation of strained heteroepitaxial growth with intermixing using kinetic Monte Carlo is presented. The model used is based on a solid-on-solid bond counting formulation in which elastic effects are incorporated using a ball and spring model. While idealized, this model nevertheless captures many aspects of heteroepitaxial growth, including nucleation, surface diffusion, and long range effects due elastic interaction. The algorithm combines a fast evaluation of the elastic displacement field with an efficient implementation of a rejection-reduced kinetic Monte Carlo based on using upper bounds for the rates. The former is achieved by using a multigrid method for global updates of the displacement field and an expanding box method for local updates. The simulations show the importance of intermixing on the growth of a strained film. Further the method is used to simulate the growth of self-assembled stacked quantum dots.