Low power consumption bipolar resistive switching characteristics of ZnO-based memory devices

Abstract

Ag/ZnO/Pt structure resistive switching devices are fabricated by radio frequency (RF) magnetron sputtering at room temperature. The memory devices exhibit stable and reversible resistive switching behavior. The ratio of high resistance state to low resistance state can reach as high as 10 2 . The retention measurement indicates that the memory property of these devices can be maintained for a long time (over 10 4 s under 0.1-V durable stress). Moreover, the operation voltages are very low, -0. With the recent development in the microelectronic industry, a new concept, the resistive random access memory (ReRAM), has attracted considerable attention in the field of storage technology [1,2] . This memory cell based on metal/insulator/metal (MIM) structure, in which resistance can be repeatedly switched between a high and a low value by applying an electric field, is a potential replacement of flash memory in next-generation non-volatile memory (NVM).The resistive switching phenomenon has been observed in various materials, such as perovskite oxides SrTiO 3[3] , solid electrolytes [4] , and polymers [5] . However, these materials have their own notable disadvantages. For example, a solid electrolyte needs high write operation voltage, polymer is limited by low endurance, etc. Transition metal oxides (TMOs), such as ZnO, ZrO 2 , NiO, TiO 2 , and Al 2 O [6−13] 3 , are extensively studied due to their simple constituent, excellent compatibility with complementary metal oxide semiconductor (CMOS) technology, and the capability for high scalability. The current-voltage (I-V ) characteristics of the TMOs exhibit a large change resistance between high resistance state (HRS) and low resistance state (LRS) for logic off-state and logic onstate.Compared with other devices, ZnO-based devices are promising candidates for binary oxide memory application, due to their low price, long retention time, and non-destructive readout. However, several reports have shown that the operation voltages are slightly higher and devices need a forming process in the initial state [7,14] . In this letter, ZnO-based memory devices with Ag electrode were fabricated by radio frequency (RF) magnetron sputtering, and the resistive switching properties were investigated. The devices showed the bipolar resistive switching behavior with operation voltage of less than 1 V and operating current of less than 25 mA, which are significantly lower than the results of Refs. [14,15]. The non-electroforming process was obtained in our devices, which is suitable for high-density ReRAM device application. Multi-step switching processes were also observed, which can be used for multi-level memory applications.In the fabrication of the ReRAM devices with Ag/ZnO/Pt structure, approximately 100-nm ZnO film was deposited on Pt/Ti/SiO 2 /Si substrates by RF magnetron sputtering at room temperature using a metallic Zn target. The device structure is shown in Fig. 1. A thin Ti layer was inserted between the layers of Pt and SiO 2 /Si to enhance the adhesion of Pt el...

The Recent Advances of Research on Memristor and Memristive Characteristic Devices

“…Lin's first work [9] investigated the resistive switching characteristics of Al/ZnO/Al RRAM for ZnO film with and without N2 RTA treatment; He's second work [10] investigated the characteristics of ZnO film as resistive RAM (RRAM) using Al electrode. Zhao [11] explored the effect of electrode material to the properties of resistance. Resistive switching device with the Ag/ZnO/ITO structure is constructed for comparison with the Ag/ZnO/Pt device.…”