Tuning the Memory Window of TaOx ReRAM using the RF Sputtering Power

In this work, TaOx based ReRAM devices were fabricated by reactive sputtering. The impact of RF power on the device characteristics was investigated using five different RF powers ranging from 116 W (RF 20%) to 356 W (RF 60%), resulting in different film deposition rates. Depending on RF power, both the initial device resistance (R initial ) and forming voltage (V FORM ) were found to be changed. The switching layer sputtered at 116 W shows the highest R initial (80 GΩ), whereas the lowest resistance (50 kΩ) is obtained at 236 W. The device RESET level (R OFF ) is a function of R initial and V FORM . The largest memory window (R OFF / R ON ~ 105) and 2-bit MLC operation are achieved at 236 W deposition power. These devices show excellent retention at 125 °C for 10 4 seconds and good endurance up to 10 6 cycles. These results reflect the impact of the sputtering deposition power on the electrical performance of the ReRAM devices. It is due to the fact that the structural defects and oxygen content in the deposited film are modulated by the sputtering power.