Characterization of sub-stoichiometric rhodium oxide deposited by magnetron sputtering

The preparation and detailed characterization of sub-stoichiometric rhodium oxide films prepared by magnetron sputtering at room temperature have been carried out on silicon substrates. Effects of the oxygen gas flow ratio on chemical bonding state, optical reflectivity and crystallinity were investigated using XPS, reflectivity measurements, XRD and SEM. For oxygen flow ratios higher than 2%, the films become amorphous with high resistivity (1.5 × 10−5 Ω m) indicating semiconducting properties. The same experiments were performed at 300 °C and even with high oxygen gas flow ratio the films always have a metallic component. Moreover, for high fractions of oxygen in the plasma, films are always sub-stoichiometric.