A. Krozer et M. Rodahl, X-RAY PHOTOEMISSION SPECTROSCOPY STUDY OF UV OZONE OXIDATION OF AU UNDER ULTRAHIGH-VACUUM CONDITIONS/, Journal of vacuum science & technology. A. Vacuum, surfaces, and films, 15(3), 1997, pp. 1704-1709
Citations number
21
Categorie Soggetti
Physics, Applied","Materials Science, Coatings & Films
(111) textured Au films were oxidized under UHV conditions by exposing
them to UV radiation and ozone. The Au films were characterized by x-
ray photoelectron spectroscopy. The gold surface becomes heterogeneous
upon oxidation: approximately 0.8 monolayer (ML) of the adsorbed oxyg
en is present as chemisorbed species. The rest of the adsorbed oxygen
forms, on the average, a few ML thick gold oxide with a stoichiometry
close to Au2O3. Both the oxide and the chemisorbed oxygen disappear sl
owly when heated to 150 degrees C. During isothermal decomposition at
200 degrees C, the oxide is transformed to chemisorbed oxygen prior to
desorption. Both the chemisorbed oxygen and the gold oxide can be rem
oved by rinsing with water. The surface is hydrophilic after the rinse
. When contaminated gold films are exposed to UV/ozone, impurity oxide
s appear at higher binding energies than the binding energies of oxyge
n on clean gold samples. The impurity oxides are thermally much more s
table than Au2O3. (C) 1997 American Vacuum Society.