Drastic reduction of RRAM reset current via plasma oxidization of TaOx film

Reducing reset current is crucial for practical applications in RRAM. To lower reset current, the further oxidization of the as-deposited TaOx films was carried out with the treatment of oxygen plasma, and then Pt/TaOx/Pt devices with a diameter of 200 μm were fabricated using magnetron sputtering. The reset current of the devices was reduced, from more than 10 mA to 40 μA, by more than two orders of magnitude. The device stability was also improved by the plasma oxidation process. The formation of a large quantity of Ta2O5 after the plasma oxidation was confirmed by X-ray photoelectron spectroscopy. The results implied that most of Ta2O5 layer in the region near the top electrode was formed after the plasma oxidation and played an important role in resistive switching of the devices.