Realization of forming-free Ag/ZrO2-based threshold selector with high selectivity by optimizing film thickness and scaling down electrode size

The influence of the switching layer thickness and the device size on the threshold switching characteristics has been investigated in Ag/ZrO2/Pt selector device. By optimizing the switching layer thickness, excellent threshold switching characteristics such as forming-free behavior, high selectivity and good endurance was achieved. In addition, we revealed the impact of active metal electrode diffusion on the device performance as the thickness of dielectric material scaled. A two-step set behavior was also observed in the device with 80 nm switching layer under a high compliance current of 1mA. Furthermore, the selectivity was increased highly by decreasing electrode size. In particular, the selectivity was about 2×108 when the electrode size was scaled down to 300 nm.