Strain distribution during growth of Ge/Si(001) and the effect of surfactant layers

Grazing incidence X-ray diffraction has been employed to determine directly the distribution of strain in the plane of the interface during deposition of Ge onto Si(001). The corresponding strain distribution has also been deduced for a relaxed island whose atomic structure has been determined by molecular dynamics. The results illustrate the central role of elastic deformation of islands in the initial stage of strain relief. The results are also compared with those for growth with a Sb surfactant layer which suppresses island formation. An investigation of surfactant-like behaviour is also presented for homoepitaxial growth of Ag on Ag(111), where submonolayer coverages of Sb promote a layer-by-layer growth mode over a wide temperature range.