SURFACE MECHANISMS IN THE UVCVD OF SIO2-FILMS

Surface-sensitive multiple internal reflection absorption infrared spectroscopy has been applied to the study of the growth of SiO2 films under far ultraviolet illumination. Spectra provide evidence for a previously unreported Si-H absorption peak occurring at 2208 cm-1. It is shown that this line characterizes the molecular structure of the photochemisorption site of silane and that this phenomenon occurs on sites including hydroxyl groups which are also produced in a photochemical gas-solid process. In the first step of silane photochemisorption, photoexcitation occurs on the surface while in the oxidization step, photoexcitation of oxygen molecules is an active process in the gas phase.