A model for the distribution of misfit dislocations near epitaxial layer interfaces

We present Monte Carlo simulations of the process of misfit relief in strained epitaxial layer interfaces. The emphasis is on the effect on the distribution of dislocation spacings owing to the reactions of 60° dislocations to form edge dislocations. When there are no edge dislocations the distribution is a decaying exponential function, but as the edge dislocation density increases a peak appears in the distribution. The position and magnitude of this peak depend on the proportion of edge dislocations found within the misfit dislocation array. We also take into account the effects of the experimental resolution on the appearance of the histograms. The results are consistent with detailed experimental measurements of dislocation spacing distributions and are important since the energy of an array increases significantly when the dislocation spacings are non-periodic.