LAUSR

We report on the resistive switching effect in metal-insulator-metal (MIM) structures Pt/Ta2O5+x/Ta with over-stoichiometric tantalum oxide film. These devices exhibit forming-free behavior, Roff/Ron ratio10 and high endurance (108cycles). Based on the experimentally observed correlation between the applied voltage and the resistance changes (bias memory effect - BME), the resistive switching model for this kind of devices is proposed. Display Omitted Process of overstoichiometric tantalum oxide deposition is presented.Structural properties of oxide were studied by RBS and XPS.Electrical properties of oxide were analyzed in Pt\oxide\Ta forming-free structure (initial state is between LRS and HRS).Resistive switching effect in Pt\oxide\Ta structure with promising characteristics (Roff/Ron ~10, 108 cycles) is detected.Bias memory effect in Pt\oxide\Ta structure and its explanation by model of resistive switching effect is proposed.