X-ray reflectivity and X-ray photoelectron spectroscopy studies on reactively sputtered Nb2O5-based thin-film devices

The reactively sputtered Nb2O5-based metal-oxide-semiconductor devices deposited under different O-2/Ar ratios have been studied using laboratory-based X-ray reflectivity (XRR) and synchrotron-based X-ray photoelectron spectroscopy techniques. The I - V characteristics reveal a sharp transition in the magnitude of current (similar to up to five orders) signifying a switching phenomenon between high-resistance and low-resistance states. The electron density profile, derived from XRR data, shows a dependence of the switching properties on the film porosity. Further, the non-lattice oxygen in the film also plays a role in determining the on/off ratio of the devices. Therefore, besides the presence of non-lattice oxygen, film porosity also influences the resistive switching behavior of the Nb2O5-based devices.