Multilevel data storage memory based on polycrystalline SrTiO3 ultrathin film

Abstract

Resistive switching random access memory (RRAM) has recently inspired scientific and commercial interest due to its high operation speed, high scalability, and multilevel data storage potential. However, the switch ratio, energy consumption and retention are still not satisfactory in the devices based on perovskite oxides. Herein, we have prepared polycrystalline SrTiO₃ ultrathin film based multilevel data storage memories with different top electrodes and investigated the different performances of these devices. The multilevel data storage of the device with an Ag top electrode is achieved by controlling the shape of the Ag filament using voltage pulses, and the switching ratio can be as high as 10⁷%. The multilevel data storage of device with a Pt top electrode, for comparison, is achieved by controlling the distance of oxygen vacancies migration using voltage sweeping, and the switching ratio is about 10⁶%. The devices, all with good retention, suggest a new opportunity for polycrystalline SrTiO₃ ultrathin film based resistive switching devices as high storage density, low-energy and cheaper nonvolatile memories.