Unipolar resistive switching characteristics of pnictogen oxide films: Case study of Sb₂O₅

Resistive switching (RS) and electrical endurance characteristics of amorphous Sb₂O₅ films in Pt/Sb₂O₅/Pt and Sb/Sb₂O₅/Pt structures were examined. Although both structures showed unipolar RS characteristics with power consumption smaller than those of other various transition metal oxides by ∼ two orders of magnitude, enhanced electrical endurance was obtained when Sb was employed as the top electrode than when Pt was employed as the top electrode. This improvement was explained by the creation of Sb clusters in the Sb ₂O₅ films through the diffusion of oxygen from Sb ₂O₅ to the Sb layer and the suppression of excessive oxygen loss during conducting filament formation process by the Sb top electrode. Metallic Sb clusters in pristine Sb₂O₅ films were confirmed by X-ray photoelectron spectroscopy depth profiling measurements and Auger electron spectroscopy. From the results of current density variation as a function of sample area, it was confirmed that the RS properties of Sb ₂O₅ were controlled by the localized conducting filament in Sb₂O₅; this finding was in agreement with the result of high resolution transmission electron microscopy. The RS properties of this pnictogen oxide material are discussed with the RS properties of other transition metal oxide materials.