Low power/self-compliance of resistive switching elements modified with a conduction Ta-oxide layer through low temperature plasma oxidization of Ta thin film

A Ta ultra-thin metal layer was treated by O2 plasma at low temperature to form TaOx, which severs as a resistive element or internal resistor. The low current operated Ta/TaOx/HfOx and Ta/TaOx/AlOx devices exhibit self-compliance, good LRS nonlinearity (>40), robust retention at 85 °C, and enough endurance (>1000). A plausible mechanism is proposed. The low temperature plasma oxidation of Ta layer is demonstrated an potential process for vertical RRAM with self-compliance and low current operation of 5 μA.