Threshold switching-based bidirectional nonlinear characteristics of ZnTe selectors for 3D stackable crossbar array applications

Abstract

Three dimensional (3D) stackable memory devices including crossbar array frames have emerged as a promising candidate for the realization of high-density non-volatile memory electronics. However, the crossbar array using two terminal element is highly susceptible to sneak path issues that arise from unintended leakage current since each cell in a row and column is connected to each other. Thus, the integration of a suitable selector as a two way switches is crucially required. Here, we address electrical features of ZnTebased selector, ensuring high bidirectional non-linearity of more than 10⁴ . Typical threshold switching (TS) after forming process was clearly observed, along with attaining the exponential increase in the Off-current with increasing voltages. We propose the possible conduction nature in the Off-current by utilizing a modified Poole-Frankel (PF) model. The observed threshold voltages of the selector exhibited a thickness dependency, thereby implying an adjustable nature in the device.