Oxygen atom-induced D2 and D2O desorption on D/Si(111) surfaces

We studied reaction of oxygen atoms with D-terminated Si(111) surfaces from a desorption point of view. As the D (1 ML)/ Si(111) surface was exposed to O atoms D-2 and D2O molecules were found to desorb from the surface. The desorption kinetics of D-2 and D2O molecules exhibited a feature characterized with a quick rate jump at the very beginning of O exposure, which was followed by a gradual increase with a delayed maximum and then by an exponential decrease. The O-induced D-2 desorption spectra as a function of T-s appeared to be very similar to the H-induced D-2 desorption spectrum from the D/Si(111) surfaces. Possible mechanisms for the O-induced desorption reactions were discussed. (C) 2003 Elsevier B.V. All rights reserved.