Photon-stimulated desorption (PSD) experiments on thermal oxide films on Si have been performed using synchrotron radiation with photon energies in the Si 2p core-level excitation region, to investigate the chemical nature of the film surface. Mass analysis of the PSD ions is performed using a time-of-flight technique. H + is found to be the dominant ion species that desorbs from the film surface. It is observed that the H +PSD ion yield decreases exponentially with increasing the irradiation time of incident photons. The H +PSD ion yield as a function of photon energy exhibits a close similarity in spectral shape to the photoabsorption spectrum of SiO2. The present experimental results confirm us that hydrogen atoms exists on the outermost layer of SiO2 film, and provide direct evidence for Si-OH and Si-H termination of SiO2 films.
|Number of pages||5|
|Journal||Journal of Vacuum Science and Technology A: Vacuum, Surfaces and Films|
|Publication status||Published - 1991 Mar 1|