Set compliance current induced resistive memory characteristics of W/Hf/HfOx/TiN devices

Abstract

In this paper, the authors have investigated the effect of current compliance during the set process on the resistive memory characteristics and switching mechanism of W/Hf/HfOx/TiN devices. The presence of an Hf thin cap layer enables the stable and uniform bipolar resistive switching behavior. Compliance current can modify the barrier height at the oxide-electrode interface by increasing or reducing the oxygen vacancies and induce different switching mechanisms. Low compliance current (50 μA) based switching confirms the Schottky conduction mechanism due to the interfacial effects, while high compliance current (500 μA) involves the ohmic conduction mechanism, signifying the formation of a conductive filament. No significant dispersion of reset current and reset voltage has been found for each set compliance current varying from 50 to 500 μA, indicating uniform performance of the devices. The devices also exhibited a read endurance up to 2000 cycles.