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 interac tion between atoms is only based on an assessment of the Hamiltonian a nd does not require any assumption of a discrete crystal lattice. Two different types of potentials were chosen for the simulation of the in teraction 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 investi gated island and layer growth in the nucleation stage. Our simulation also allowed the selection of vicinal surfaces of the substrate with r espect to the usually used (111) oriented surface. The simulation show ed a clear stabilisation of the growth direction by the atomic steps o n the substrate and even in lattice mismatched structures the formatio n of twins was suppressed. In the case of the directional Lennard-Jone s potential with the fourfold symmetry we found that the crystalline s tructure disappeared after the deposition of one monolayer.