Switching characteristics in TiO2/ZnO double layer resistive switching memory device

Abstract

The uniform and reliable resistive switching characteristics of a ZnO based resistive random access memory device with a thin TiO2 layer are successfully investigated. In this study, the effect of thickness of the TiO2 layer on switching characteristics has been investigated. Compared with different thicknesses of the thin TiO2 layer, the remarkably improved resistive switching parameters such as lower forming voltage and the narrower variation of endurance are achieved for a TiO2 layer of thickness 2 nm. The forming voltages are dependent on the TiO2 thickness which supports the idea that forming process is governed by a dielectric breakdown-like phenomenon. The Ti/TiO2/ZnO/Pt device with the 2 nm TiO2 layer exhibits good DC endurance up to 10(3) cycles. The non-volatility of data storage is further confirmed by retention test measured at room temperature. It has been observed that both low resistance state and high resistance state do not exhibit any degradation for more than 10(4)s.