ATOMIC-SCALE SIMULATION OF INTERFACE DEFECT FORMATION IN THE INITIAL-STAGES OF THIN-FILM GROWTH

We have performed an atomic-scale simulation of lattice-mismatched het eroepitaxial growth of semiconductors with a zincblende structure by a ssociating the Monte Carlo technique with an energy model based on the valence force field approximation. We have observed the formation of misfit dislocations by alignment of point defects. We have evaluated t he critical thickness for their creation which are in good agreement w ith experimental results for high lattice mismatches (greater than 6%) , while previous macroscopic models give good results for low lattice mismatches (less than 4%). The deposition of alloy films is investigat ed to study the variations in the density and the nature of interface defects, leading to misfit dislocations.