Computer simulation of quantum dot formation during heteroepitaxial growth of thin films

Influence of mismatch on quantum dot formation during heteroepitaxial growth of thin films with zinc blende structure on GaAs substrate is investigated. A kinetic Monte Carlo model is used for simulation of thin films with different values of lattice mismatch in the range of 4% to 14%. Simulation is performed at a substrate temperature of 700 K and deposition rate of 0.3 ML/s. Also, 'reflection high-energy electron diffraction' (RHEED) intensity of simulated thin films is evaluated during growth. Results of simulation show that at constant temperature and deposition rate, quantum dot size decreases with increasing lattice mismatch, and their distribution function becomes sharp. Simulated RHEED oscillations have a good agreement with morphology of simulated thin films, and results show that growth mode changed from Stranski-Krastanov to Volmer Webber by increasing lattice mismatch.