  The effects of wet chemical processing conventionally employed in device
fabrication standards are systematically studied on molybdenum oxide (MoOx)
ultra-thin films. We have combined x-ray photoelectron spectroscopy (XPS),
angle resolved XPS and x-ray reflectivity techniques to provide deep insights
into the changes in composition, structure and electronic states upon treatment
of films with different initial stoichiometry prepared by reactive sputtering.
Our results show significant reduction effects associated with the development
of gap states in MoOx, as well as changes in the composition, density and
structure of the films, systematically correlated with the initial oxidation
state of Mo.
