Filamentary resistive switching in amorphous and polycrystalline Nb2O5 thin films

In this paper, the correlation between the crystallinity of reactively sputtered Nb2O5 layers on Pt bottom electrode and their resistive switching behavior was investigated. It was found that the amorphous phase can transformed to an orthorhombic phase by annealing in argon at 650 °C. Smooth surfaces of the crystalline samples with RMS roughness of 1 nm were produced. By using the stack Al/Nb2O5/Pt a Schottky diode was produced and a barrier height of 1.0 eV for the argon annealed sample was found. For the amorphous sample, a Frenkel–Poole emission mechanism was found with the activation energy of 0.21 eV. After an electric forming process a filamentary resistive switching was observed for both types of samples.

► Amorphous Nb2O5 on platinum can be transformed to an orthorhombic phase by annealing in argon at 650 °C.
► By using the stack Al/Nb2O5/Pt a Schottky diode with a barrier height of 1.0 eV for the argon annealed sample was found.
► After an electric forming process a filamentary resistive switching was observed for amorphous and crystalline Nb2O5 samples.