Temperature-driven crossover from abrupt thermal to gradual field-driven RESET in single-layer HfO₂ RRAMs

We investigate the temperature-dependent resistive switching behavior of single-layer ITO/HfO₂/TiN resistive random access memory devices down to 10 K. Devices formed at room temperature exhibit abrupt, Joule-heating-assisted RESET transitions that evolve into gradual, field-driven processes upon cooling. We found that the RESET voltage increases steadily with decreasing temperature, while the memory window narrows yet remains above 10× at 10 K, enabling clear separation of states in the cryogenic regime. Double-log I–V slope analysis reveals a crossover from thermally activated to field-driven conduction as the temperature is reduced, consistent with suppressed vacancy mobility and a reduced impact of Joule heating at low temperature. Devices formed directly at 10 K exhibit the same gradual switching behavior, and the RESET becomes increasingly abrupt upon reheating, confirming that the mechanism intrinsically depends on temperature. Although the memory window decreases at cryogenic temperatures, the stable and reproducible operation of this simple single-layer oxide stack highlights its potential for integration in cryogenic CMOS memory and neuromorphic systems.