Controllable oxygen vacancies to enhance resistive switching performance in a ZrO2-based RRAM with embedded Mo layer

In this study, the resistive switching characteristics of a ZrO₂-based memory film with an embedded Mo layer are investigated. The experimental results show that the forming process can be removed by inserting an embedded Mo metal layer within ZrO₂ via a post-annealing process. The excellent memory performance, which includes lower operation voltage (<1.5 V), good endurance (>10³ cycles), a stubborn nondestructive readout property (>10⁴ s), and long retention time (>10⁷ s), is also demonstrated. Moreover, high-speed operation (10 ns) can be successively maintained over 10³ cycles without any operational errors observed in this memory device. Due to the interface layer induced by the Ti top electrode, the formation and rupture of conducting filaments are suggested to occur near the Ti/ZrO₂ interface. The oxygen vacancies induced by the embedded Mo can enhance the formation of conducting filaments and further improve the switching characteristics in ZrO₂-based devices.