Vibrational spectroscopy of SiO on Si(111)

The growth of ultrathin SiO layers on clean Si(111) was observed by in situ infrared spectroscopy under ultra-high vacuum conditions. SiO was deposited by thermal evaporation of SiO powder from a Knudsen cell. A large shift of the SiO main vibrational line, from about 864 cm(-1) for sub-monolayer coverage up to the bulk value of SiO at about 982 cm(-1) for thicknesses above 10A, was observed. The extraordinary low vibrational frequencies for species at the SiO-Si interface corroborate recently published theoretical results for SiO adsorption on Si and for the SiO2-Si interface. (C) 2010 WILEY-VCH Verlag GmbH & Co. KGaA, Weinheiminfrared spectroscopylattice propertiessilicon monoxide