3-DIMENSIONAL MODEL CALCULATION OF EPITAXIAL-GROWTH BY MONTE-CARLO SIMULATION

We report on a three-dimensional model calculation of epitaxial growth by Monte Carlo simulation. Our theoretical description of the interaction between atoms is only based on an assessment of the Hamiltonian and does not require any assumption of a discrete crystal lattice. Two different types of potentials were chosen for the simulation of the interaction between the adatoms and the substrate atoms: (a) a spherical symmetric Lennard-Jones potential to describe hard spheres and (b) a directional Lennard-Jones potential with fourfold symmetry. We investigated island and layer growth in the nucleation stage. Our simulation also allowed the selection of vicinal surfaces of the substrate with respect to the usually used (111) oriented surface. The simulation showed a clear stabilisation of the growth direction by the atomic steps on the substrate and even in lattice mismatched structures the formation of twins was suppressed. In the case of the directional Lennard-Jones potential with the fourfold symmetry we found that the crystalline structure disappeared after the deposition of one monolayer.