STRUCTURE AND GROWTH KINETICS OF SiO2 ULTRA THIN FILM ON Si(111) SURFACE

The structure and the growth of very thin films of silicon oxide on top of atomically clean silicon surfaces have been investigated with surface techniques such as AES, ELS, LEED and XPS under UHV conditions. A transition layer was found to form at the Si-Si02 interface. The growth kinetics could be explained by a phenomenological model based on oxygen diffusion through the oxide layer under the presence of a surface electric field. Finally the Si oxidation has also been examined with XPS technique when some metallic impurities were evaporated onto the Si surface prior to oxygen exposure. An enhanced reactivity was observed and attributed to the covalent sp3 bond disruption which was provoked by metallic impurities.