Defects in the supercritical thickness strained-Si layer grown on a fully relaxed SiGe buffer layer were investigated by atomic force microscopy and transmission electron microscopy. The atomic force microscopy observation of chemically etched surfaces showed that etch pits having a crosshatch pattern due to misfit dislocations decrease and segments and deep valley profiles increase with an increase in the strain energy of the Si. It was found that the segment corresponds to an extended dislocation, of which a 30° partial was in the strained-Si layer and a 90° partial was in the SiGe layer, and the deep valley corresponds to a stacking fault found by a high-resolution transmission electron microscopy observation. A model of the generation of the stacking fault related to development of the misfit dislocation was also considered here.

Generation of Misfit Dislocations and Stacking Faults in Supercritical Thickness Strained-Si/SiGe Heterostructures. Y.Kimura, N.Sugii, S.Kimura, K.Inui, W.Hirasawa: Applied Physics Letters, 2006, 88[3], 031912 (3pp)