Selector-memory device voltage compatibility considerations in 1S1R crosspoint arrays

In 1S1R (one-selector one-resistor) crosspoint memory arrays, a nonlinear selector device is connected in series with each memory element to address the inherent sneak current paths problem. It is crucial that the selector device achieves voltage compatibility with the memory element for acceptable write and read performance of the array. We present a study on the relationship between the switching voltage of the memory element, Vsw and the threshold voltage of the selector device, Vth that must be met for voltage compatibility. The study also takes into account parameter variations induced by the fabrication process. Using mathematical models and circuit simulations, we demonstrate that the write and read requirements set the maximum and the minimum allowed values, respectively, of Vsw/Vth, which determines the design space for 1S1R crosspoint memory array design