Interface dislocations forming during epitaxial growth of GeSi on (111) Si substrates at high temperatures

During high-temperature epitaxial growth of GeSi layers on (111) Si substrates the relaxation of misfit stresses produces regular misfit dislocation networks in the GeSi/Si interface. In these networks the misfit dislocations dissociate into Shockley partial dislocations with Burgers vectors parallel to the interface. The dissociation leaves behind intrinsic and extrinsic stacking faults, which cover a major fraction of the GeSi/Si interface. Observations on the early stages of layer growth indicate that the GeSi grows layer by layer, and that the critical layer thickness for misfit stress relaxation corresponds to the thickness expected from the energy criterion of Matthews and Blakeslee. Experimental observations of misfit dislocations forming during cyclic heating of as-grown GeSi/Si layers reveal the mechanisms by which misfit dislocations with Burgers vectors parallel to the GeSi interface can form.