A new model was proposed for the thickness dependence of the threading dislocation densities in mismatched hetero-epitaxial semiconductor layers. This so-called glide model was based upon the assumption that dislocations established mechanical equilibrium between the line tension in their misfit segments and the glide force which was experienced by their threading segments. The glide model correctly predicted the inverse relationship between film thickness and dislocation density in mismatched hetero-epitaxial layers which were much thicker than the critical thickness. It also predicted the weak dependence of the dislocation density upon lattice mismatch. The quantitative predictions of the glide model were in reasonable agreement with published experimental data, and no adjustable parameters were used.

New Model for the Thickness and Mismatch Dependences of Threading Dislocation Densities in Mismatched Hetero-Epitaxial Layers. J.E.Ayers: Journal of Applied Physics, 1995, 78[6], 3724-6