High performance low power multilevel oxide based RRAM devices based on TiOxNy/Ga2O3 hybrid structure

Abstract

In this study, the resistive memory devices with Ag/TiOxNy/Pt structure and Ag/TiOxNy/Ga2O3/Pt structure are fabricated. The results showed that they exhibit typical resistive behaviors as well as excellent cycling and retention characteristics (>104 s). Especially, the double-layer device with Ga2O3 layer exhibits superior resistive behavior, which has a larger storage window (ON/OFF ratio >105), a smaller set voltage (0.17 V) and a reset voltage (−0.057 V), and lower power consumption (21.7, 0.17 μW) compared with the single-layer device. Furthermore, the Ag/TiOxNy/Ga2O3/Pt device demonstrates ultraviolet light (UV-365 nm)-dependent resistance state (RS), which is advantageous for multilevel memory cells. As the intensity of UV light increases, eight high resistance state (HRS) levels are produced. Finally, the conductive mechanism for both device structures is discussed, and it is found that the conductive filaments mechanism dominates in the low resistance state. However, for the HRS, the single-layer TiOxNy device is dominated by the space charge-limited conduction mechanism, and the double-layer TiOxNy/Ga2O3 device is dominated by the Schottky emission mechanism.