Physics in designing desirable ReRAM stack structure — Atomistic recipes based on oxygen chemical potential control and charge injection/removal

We clarify the importance of three-layers ReRAM stack-structures and provide guidelines for further optimization by both charge injection/removal and oxygen chemical potential. We determine atomistic structures corresponding to the ON-OFF switching process of ReRAMs using ab initio calculations. The cohesion-isolation of oxygen vacancies is found to be a strong driving force in the ON-OFF switching observed in oxide-based ReRAMs, and this phase transition can be controlled by injecting/removing charges while altering the oxygen chemical potential. Based on this concept, we propose universal guidelines for designing desirable ReRAM stack structures by introducing an oxygen vacancy barrier layer.