TID and Displacement Damage Resilience of 1T1R HfO₂/ Hf Resistive Memories

RRAM memory cells demonstrate resilience to ionizing dose and displacement damage, despite the presence of a nonhardened access transistor. Degradation in RRAM performance was not observed until large displacement damage doses and complete functionality was regained by cycling. A significant reduction in both the high and low resistance memory states and a complete collapse of the resistive window was observed for large proton fluences in RRAMs tested. Degradation in resistance states is associated with the generation of additional vacancies, which leads to (an) additional filament(s) in parallel to the existing conductive filament. Additional vacancies from displacement damage in the oxide of the resistive element do not permanently degrade device operation. The low resistance state is recovered to the pre-irradiation resistance through cycling at nominal high-speed switching conditions. Recovery of the resistive window to pre-irradiation values is obtained by applying longer write pulses which migrate remnants of radiation-induced filaments.