Analysis of growth on 75 mm Si (100) wafers by molecular beam epitaxy using in vacuo scanning tunneling microscopy

Abstract

We have placed a scanning tunneling microscope (STM) in vacuo with a commercial molecular beam epitaxy (MBE) system for the study of interfaces during device growth. The STM was designed to accept 75 mm MBE wafers, thereby guaranteeing the STM results would be valid for device growths. We review the results of our investigations into the homoepitaxial growth of Si on Si, the heteroepitaxial growth of SiGe alloys and the doping of Si with Sb and B. All surfaces were produced by materials deposition rates at 0.1 nm s −1 and at growth temperatures between 350 and 800 °C. We report, for Si homoepitaxy, the transition in growth mode from step flow to 2-dimensional islanding as a function of temperature and we present new insights into the development of RHEED oscillations. Associated with the heteroepitaxial growth of SiGe alloys, we present the effect of Ge segregation and film strain on surface morphology. Doping of Si with Sb is shown to produce 3-dimensional islands and the doping of Si with B is shown to produce surface pits.