Atomic scale simulation of epitaxial growth: Cases of GaAs/GaAs and CdTe/GaAs

We present a kinetic Monte Carlo model describing the growth by molecular beam epitaxy (MBE) of semiconductor compounds and including a local photoemission model with reflection high-energy electron diffraction (RHEED) intensity for comparison. We investigate the cases of both homoepitaxial and heteroepitaxial growth. The valence force field approximation is used for the strain energy calculations in mismatched thin films In homoepitaxial growth of GaAs, we have study the variations of photoemission current and RHEED intensity and examined the GaAs morphology. In high lattice mismatch heteroepitaxial growth (CdTe/GaAs), we have shown the formation of grooves corresponding to (111) facets, precursor to the formation of misfit defects.We present a kinetic Monte Carlo model describing the growth by molecular beam epitaxy (MBE) of semiconductor compounds and including a local photoemission model with reflection high-energy electron diffraction (RHEED) intensity for comparison. We investigate the cases of both homoepitaxial and heteroepitaxial growth. The valence force field approximation is used for the strain energy calculations in mismatched thin films In homoepitaxial growth of GaAs, we have study the variations of photoemission current and RHEED intensity and examined the GaAs morphology. In high lattice mismatch heteroepitaxial growth (CdTe/GaAs), we have shown the formation of grooves corresponding to (111) facets, precursor to the formation of misfit defects

Simulation of surface morphology and defects in heteroepitaxied thin films

We have performed atomic scale simulations of heteroepitaxial growth of thin films using the valence force field approximation and Monte Carlo techniques. The case of CdTe/(001)GaAs is considered. Our simulations indicate valley formation presenting (111) facets with unstable bottoms in the early stages of the growth. This roughening is a source of dislocation, as it appears to relax the elastic energy of the deposited layers by formation of V-grooves. We have used a calculated RHEED as an in situ control of deposited layers. Finally, we present the influence of an imperfect surface in the morphology of the deposited films