The effect of substrate relaxation on the introduction of misfit dislocations in misfitting epitaxial layers

Abstract

The effects of substrate relaxation and curvature on the stress levels and the introduction of misfit dislocations in epitaxial layers are considered. The stress distribution in single- and multi-layer epitaxial structures are calculated, employing elastic energy minimization. The results are found to differ significantly from those previously reported, the stress levels being up to 60% greater. These results are combined in a calculation of substrate curvatures and critical thicknesses for misfit dislocation introduction taking into account the substrate relaxation. It is shown that, under certain conditions, Substrate relaxation and misfit dislocation interaction with the epilayer stress both markedly impede the initial introduction of misfit dislocations into the interface.