Fully relaxed, high-quality Ge layers were grown directly on Si(001) substrates by surfactant-mediated epitaxy at high temperature with large Sb flux. The low dislocation densities in the present films were attributed to an abrupt strain relief via the formation of a regular array of 90° dislocations at the interface during the initial, micro-rough stage of growth. This mechanism of abrupt strain relaxation occurred exclusively under high Sb coverage at about 700C. The high growth temperature also enhanced Sb segregation leading to a low background doping level of only (3–4 x 1016)/cm3. Surfactant-mediated epitaxy of relaxed Ge on Si(001) was regarded as being a promising candidate for device application.

Surfactant-Mediated Epitaxy of Relaxed Low-Doped Ge Films on Si(001) with Low Defect Densities. T.F.Wietler, E.Bugiel, K.R.Hofmann: Applied Physics Letters, 2005, 87[18], 182102 (3pp)