AFM anodization studied by spectromicroscopy

In this paper we present a spatially resolved photoemission spectroscopy analysis of silicon-oxide nanopatterns produced by atomic force microscope (AFM) induced anodization on a n-type silicon substrate. The oxide geometry, that consists in submicrometer narrow lines of different thickness, is equivalent to the geometry used to fabricate AFM defined nanodevices such as quantum point contacts and single electron transistor. We found that the chemical properties of the oxides are spatially uniform below our spatial resolution, even in case of very thin lines, and that the oxide composition does not depend on the anodization parameters. We observed a shift of the oxide binding energies that we attributed to charging effects and that is compatible with a pure and stoichiometric silicon oxide.