Silicon–Ge layers of either 200 or 250nm were grown via molecular-beam epitaxy onto p-type (001) Si substrates. Each sample was prepared using a unique combination of buffer-layer type, buffer-layer growth temperature, and layer Ge content. Vacancy-type defects were identified using beam-based positron annihilation. These results, combined with those from previous work, indicated the size and concentration of defects in molecular beam epitaxially grown SiGe layers depend strongly upon the buffer-layer growth temperature (T). For T>500C vacancy point defect concentrations were below the detectable limit of the measurement. As T was decreased to 300C, vacancy clusters form in the buffer layer and point defects appear in the SiGe film, even for a SiGe growth temperature of 500C.Impact of Growth Conditions on Vacancy-Type Defects in Silicon–Germanium Structures Grown by Molecular-Beam Epitaxy. K.M.Shoukri, Y.M.Haddara, A.P.Knights, P.G.Coleman: Applied Physics Letters, 2005, 86[13], 131923 (3pp)