Oxygen atom-induced D2 and D2O desorption on D/Si(1 1 1) surfaces

We studied reaction of oxygen atoms with D-terminated Si(1 1 1) surfaces from a desorption point of view. As the D (1 ML)/Si(1 1 1) surface was exposed to O atoms D₂ and D₂O molecules were found to desorb from the surface. The desorption kinetics of D₂ 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 D₂ desorption spectra as a function of T_s appeared to be very similar to the H-induced D₂ desorption spectrum from the D/Si(1 1 1) surfaces. Possible mechanisms for the O-induced desorption reactions were discussed.