Low-Power Resistive Switching Characteristic in HfO 2/TiO x Bi-Layer Resistive Random-Access Memory

摘要

Resistive random-access memory devices with atomic layer deposition HfO~(2)and radio frequency sputtering TiO~(x)as resistive switching layers were fabricated successfully. Low-power characteristic with 1.52?μW set power (1?μA@1.52?V) and 1.12?μW reset power (1?μA@1.12?V) was obtained in the HfO~(2)/TiO~(x)resistive random-access memory (RRAM) devices by controlling the oxygen content of the TiO~(x)layer. Besides, the influence of oxygen content during the TiO~(x)sputtering process on the resistive switching properties would be discussed in detail. The investigations indicated that “soft breakdown” occurred easily during the electrical forming/set process in the HfO~(2)/TiO~(x)RRAM devices with high oxygen content of the TiO~(x)layer, resulting in high resistive switching power. Low-power characteristic was obtained in HfO~(2)/TiO~(x)RRAM devices with appropriately high oxygen vacancy density of TiO~(x)layer, suggesting that the appropriate oxygen vacancy density in the TiO~(x)layer could avoid “soft breakdown” through the whole dielectric layers during forming/set process, thus limiting the current flowing through the RRAM device and decreasing operating power consumption.