3-D Resistive Memory Arrays: From Intrinsic Switching Behaviors to Optimization Guidelines

3-D resistive switching random access memory (RRAM) is a promising candidate for high-density nonvolatile memory applications, as well as for monolithic 3-D integration interleaved with logic layers. In this paper, we develop a methodology for assessing and optimizing large-scale 3-D RRAM arrays. A systematic study on the intrinsic switching behaviors and optimization of 3-D RRAM arrays is performed, combining device measurements and 3-D array simulations. The dependence of programming voltage on array size, cell location and pulse parameters, statistical properties of operating 3-D RRAM arrays, and subthreshold disturbance on RRAM cells is experimentally investigated. Optimization guidelines for the performance and reliability of 3-D RRAM arrays from device level to architecture level are presented: 1) an optimized 1/n architecture for 100-kb 3-D RRAM arrays can improve write margin by 69.6% and reduce energy consumption by 75.6% compared with a conventional full-size array design; 2) a strategy of prioritizing storage location for reliable operation is presented; and 3) an optimal hopping barrier of oxygen ions is found to improve array immunity to disturbance.