PULSED MOLECULAR-BEAM REACTIVE SCATTERING OF O-2 ON SEMICONDUCTOR SURFACES STUDIED WITH RESONANCE-ENHANCED MULTIPHOTON IONIZATION

Reactive scattering of a pulse O-2 beam with semiconductor surfaces (S i and Ge) at the substrate temperature above 970 K has been studied wi th a resonance enhanced multiphoton ionization (REMPI) mass spectrosco py. Only mono-oxide species (SiO and GeO) are observed as a reaction p roduct. The vibrational and rotational state distributions of SiO deso rbed from the Si surface in the reactive scattering of O-2 at surface temperature at 1273 K are thermally equilibrium with the surface tempe rature and the vibrational distribution of GeO was also found to be th ermalized to the surface temperature at 970 K. The spatial distributio n of SiO and GeO desorption fluxes are found to be isotropic. The resu lts suggest that the mono-oxides species passed through a rotationally free state during the desorption trajectories.