Low current (5 pA) resistive switching memory using high-к Ta2O5 solid electrolyte

Bipolar resistive switching memory device using high-kappa Ta₂O₅ solid electrolyte in a Cu/Ta₂O₅/W structure with the device sizes from 0.2-8 mum was investigated. This resistive memory device has a high threshold voltage of 0.75 V, high resistance ratio (R_High/R_Low) of 3times10³, good endurance of > 10³, and excellent retention at 150degC. The memory device with a low current operation of 5 pA is obtained, for the first time, owing to the Cu metallic chain formation in the high-kappa Ta₂O₅ solid electrolyte. The strong Cu chain formation is also confirmed by monitoring both the negative voltage and current observations. The low resistance state (R_Low) decreases with increasing the current compliance from 5 pA to 700 muA, which can be useful for future multi-level data storage applications.