Understanding operation and reliability in HFOx RRAM devices through physical modeling

In this paper we investigate the physical mechanisms governing the operations and the reliability in HfOx RRAM devices using a physical model which describes self-consistently the charge transport (including trap-assisted-tunneling, Poole-Frenkel, drift, etc.), the associated power dissipation and temperature increase, the temperature- and field-assisted generation, diffusion and recombination of oxygen vacancies and ions. Model parameters, related to material and interface properties, are derived from ab-initio calculations, molecular dynamics and ad-hoc experiments. Simulation results allow understanding at quantitative level the physical mechanisms occurring during forming, set and reset operations, and those responsible of reliability (read disturbs, retention, endurance) and variability (noise, cycle-to-cycle variations) in HfOx RRAM devices.