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Threshold switching (TS) devices based on NbOx materials show intriguing potential for constructing artificial neurons in a neuromorphic machine. However, the high electroforming voltage, the low TS yield, and the poor device uniformity hinder the practical application of NbOx-based TS devices. In this work, we systematically investigate the effect of film composition on device performance by adjusting the oxygen contents in the NbOx films. The electroforming voltage decreases with lowering the oxygen content, and the forming yield for activating TS behavior increases without an additional reset process. Moreover, we propose a stacked method by inserting a NbOy layer with high oxygen content between the low oxygen NbOx layer and the bottom electrode. The intercalated NbOy layer serves as a virtual bottom electrode after breakdown, enhancing the local electrical field and improving cycle-to-cycle stability and device-to-device uniformity. These results demonstrate that the device performances are greatly improved by optimizing the oxygen content and structure, guiding for practical applications of NbOx-based TS devices in neuromorphic computing. [ABSTRACT FROM AUTHOR]

We present a new charge trapping memory (CTM) device with the Au/Ga2O3/SiO2/Si structure, which is fabricated by using the magnetron sputtering, high-temperature annealing, and vacuum evaporation techniques. Transmission electron microscopy diagrams show that the thickness of the SiO2 tunneling layer can be controlled by the annealing temperature. When the devices are annealed at 760 °C, the measured C–V hysteresis curves exhibit a maximum 6 V memory window under a ±13 V sweeping voltage. In addition, a slight degradation of the device voltage and capacitance indicates the robust retention properties of flat-band voltage and high/low state capacitance. These distinctive advantages are attributed to oxygen vacancies and inter-diffusion layers, which play a critical role in the charge trapping process. [ABSTRACT FROM AUTHOR]