On the impact of the oxide thickness and reset conditions on activation energy of HfO2 based ReRAM extracted through disturb measurements

In this paper, the failure acceleration behavior of HfO₂ based ReRAM under constant voltage and high temperature stresses is studied. We extract the activation energy from disturb measurements in the High Resistance State (HRS) for different dielectrics. Various Reset conditions are studied and correlated to the failure mechanism. Low activation energy is obtained in thin dielectric oxides. Based on the hypothesis that the activation energy is linked to the number of oxygen vacancies (i.e. residual conductive filament) in the oxide film, we show that an optimal Reset condition (in terms of voltage stop) can reduce the activation energy in thin HfO₂. On the other hand, the activation energy is higher in thick dielectrics films and it is also tunable thanks to the voltage stop of previous Reset operation.