Different set processes for bipolar resistance switching in a Ta/TaOx/Pt thin film

Abstract

We observed two different set processes, gradual and avalanche, for the resistance switching (RS) of a Ta/TaO (x) /Pt thin-film device. The gradual and the avalanche set processes could be controlled by adjusting the external reset voltage. From the current-voltage curves and the effective thickness of the insulator layer, we demonstrated that the resistance states leading to gradual and avalanche set processes were dominated by interface-limited and bulk-limited conduction mechanisms, respectively. A possible model with different effective insulator thicknesses is proposed based on conducting channel formation due to oxygen vacancies.