Comparison on TiO2 and TaO2 based bipolar resistive switching devices

Nonvolatile memories have emerged in recent years and have become a leading candidate towards replacing dynamic and static random-access memory devices. In this article, the performance of physical TiO₂ and TaO₂ nonvolatile memristive devices were compared in terms of switching speed, retention and endurance. TaO₂ memristive devices have shown better endurance (10⁸ times more switching cycles) and faster switching speed (at least 5 times) than TiO₂ memristive devices. The retention period of TaO₂ memristive devices is expected to exceed 10 years with sufficient experimental evidence. In addition to comparing device performances, the physical and material properties of TiO₂ and TaO₂ memristive devices was studied and the differences in device structure and switching mechanism of TiO₂ and TaO₂ memristive devices were explained. The reasons that give TaO₂ memristive devices the advantage over TiO₂ memristive devices in terms of switching speed, retention and endurance were summarized in this article. Also the methods to improve the performance of physical memristive devices were proposed.