Engineering Oxygen Vacancy of Tunnel Barrier and Switching Layer for Both Selectivity and Reliability of Selector-Less ReRAM

The resistive switching behaviors of selector-less resistive random access memory (ReRAM) have been extensively investigated to eliminate the tradeoff between selectivity and reliability. To achieve excellent selectivity, reliability should be sacrificed, and vice versa. The reason for this tradeoff is the narrow read operation margin of ReRAM having high selectivity. Therefore, the role of each layer has been analyzed and engineered to satisfy both selectivity and reliability requirements of the ReRAM. In the selector-less ReRAM, oxygen vacancies of the switching layer control set voltage for achieving high read operation margin, whereas oxygen vacancies of the tunnel barrier control selectivity.