It was recalled that an unusual strain relaxation phenomenon, accompanied by a reduction in threading dislocation density, had been reported in Si0.77Ge0.23 layers grown on top of alternating layers of Si0.77Ge0.23/Si0.76Ge0.23C0.01. The mechanism by which SiGeC domains, formed during annealing at 1000C, assisted the threading dislocation density annihilation process was investigated further here. A g·b analysis of transmission electron microscope images showed the formation of pure edge dislocations from the reaction of two 60° misfit dislocations, which glide and/or slip with the assistance of the localized interfacial strain of the SiGeC domains. threading dislocation density reduction in this structure was thus due to the annihilation of threading dislocation arms during misfit dislocation combination.

Threading Dislocation Reduction by SiGeC Domains in SiGe/SiGeC Heterostructure - Role of Pure Edge Dislocations. L.H.Wong, C.Ferraris, C.C.Wong, J.P.Liu: Applied Physics Letters, 2006, 89[23], 231906 (3pp