DYNAMICAL STM STUDIES OF THE GROWTH OF SILICON AND GERMANIUM ON SILICON

A scanning tunneling microscope (STM) capable of imaging during crysta l growth from the vapor is described. This method (MBSTM) opens the po ssibility to follow the growth process of semiconductor molecular beam epitaxy (MBE) ''in vivo''. The ability of the microscope to access th e evolution of specific features during growth is demonstrated by imag es of the Si homoepitaxy. A new facet of high growth speed was found u pon coalescence of 2D islands. The transition from initial multilayer to layer-by-layer growth was imaged in Si(111) homoepitaxy. In Si/Si(1 00) homoepitaxy nucleation of Si at antiphase domain boundaries was fo und and the fractional coverage of non-equivalent terraces was studied as function of coverage. A theoretically predicted transient growth m ode was observed. In Ge on Si(111) heteroepitaxy the formation of the 2D Stranski-Krastanov layer was observed.