SURFACE LOCALIZATION OF THE PHOTOCHEMICAL VAPOR-DEPOSITION OF SIO2 ON INP AT LOW-PRESSURE AND ROOM-TEMPERATURE

The first stages of the chemical vapor deposition of SiO2 on chemically polished InP substrates, promoted by UV illumination at room temperature and low (almost-equal-to 0.01 Torr) precursor pressure, have been studied in an ultrahigh vacuum environment. Chemical species deposited are found to be quite similar to those deposited by the thermally promoted process. Both Si and O atom depositions need UV illumination. The reaction rates observed in separate or mixed gas exposures indicate that surface-located mechanisms play a major part in the buildup of the SiO2/InP interface at low precursor pressure, thus opening perspectives for localized insulator growth under the UV beam.