Effect of Ar-plasma treatment of ITO layer on resistive memory properties of a Ti/ITO point-contact structure

A Ti/ITO structure was used as a point-contact resistive random access memory to simplify the procedures for conventional metal/insulator/metal structures. After the forming process, a TiOx interface was formed to fabricate a Ti/TiOx/ITO structure. The Ti/TiOx/ITO structure can be reversibly switched between a high-resistance state and a low-resistance state by using dc voltages at different polarities. The resistive switching was determined by the formation and rupture of oxygen-vacancy filaments. However, the high-forming current resulted in circuit design complexity and reliability concerns. An Ar-plasma treatment was adopted to modify the ITO surface. The Ar-plasma treatment lowered the forming current and improved memory reliability. The Ar-treated sample exhibited an endurance of more than 800 cycles through dc operation and a retention time longer than 10(4) s at 85 degrees C, making it suitable for nonvolatile memory applications.