Chemisorption of H2O on Si(100)

The chemisorption of H2O on Si(100)-(2×1) has been studied at room temperature using photoelectron spectroscopy and photon-stimulated desorption. Three H2O-induced valence orbitals are found at 6.2, 7.2, and 11.5 eV below the valence-band maximum (which is 0.4 eV below EF). They can be assigned to chemisorbed molecular H2O. The Si 2p level is chemically shifted by -0.9 eV corresponding to a single silicon-oxygen bond. Together with the observed work-function decrease, we suggest that H2O is adsorbed oxygen end down (possibly tilted). © 1983 The American Physical Society.