Dislocation Morphology and Crystalline Mosaicity in Strain-Relaxed SiGe Buffer Layers on SOI

We have grown thin strain-relaxed SiGe buffer layers on silicon-on-insulator (SOI) substrates with pure-edge dislocation network at the SiGe/SOI interface. Dislocation morphology and crystalline mosaicity of the SiGe layers have been analyzed by X-ray diffraction two-dimensional reciprocal space mapping and transmission electron microscopy. It was found that dislocation propagation at the SiGe/SOI interface and resultant crystalline mosaicity of the SiGe layer are critically dependent on the thickness of SOI layer. Image force exerted on the dislocations accounts for this SOI thickness dependence.