Reduction of threading dislocations in iso-epitaxial layers grown on (001) InP substrates by misfit stresses

A general reduction of threading dislocations over a large area of a Te-doped InP layer, grown on (001) InP:Fe by vapor phase epitaxy has been observed in the presence of interfacial misfit dislocations. However, near the edge of the epi-layer, the dislocation density increases considerably. These observations have been rationalized in terms of the misfit stress-induced glide of the threading dislocations. The estimated misfit strain is ∼0.2% and evidently results from stoichiometry mismatch between the epi-layer and the substrate.