X-ray reflectivity and X-ray photoelectron spectroscopy studies on reactively sputtered $$\hbox {Nb}_{2}\hbox {O}_{5}$$-based thin-film devices

Abstract

The reactively sputtered $$\hbox {Nb}_{2}\hbox {O}_{5}$$ -based metal–oxide–semiconductor devices deposited under different $$\hbox {O}_{2}/\hbox {Ar}$$ 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 ( $$\sim$$ 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 $$\hbox {Nb}_{2}\hbox {O}_{5}$$ -based devices.