비-휘발성 저항 변화 메모리 응용을 위한 WOx 물질의 전기적 특성 연구

In this study, we observed current-voltage characteristics of the MIM (metal-insulator-metal) structure. The WOx material was used between metal electrodes as the oxide insulator. The structure of the Al/WOx/TiN shows bipolar resistive switching and the operating direction of the resistive switching is clockwise, which means set at negative voltage and reset at positive voltage. The set process from HRS (high resistance state) to LRS (low resistance state) occurred at - 2.6 V . The reset process from LRS to HRS occurred at 2.78 V . The on/off current ratio was about 10 and resistive switching was performed for 5 cycles in the endurance characteristics. With consecutive switching cycles, the stable Vset and Vreset were observed. The electrical transport mechanism of the device was based on the migration of oxygen ions and the current-voltage curve is following (Ohm``s Law → Trap-Controlled Space Charge Limited Current → Ohm``s Law) process in the positive voltage region.