Modeling of failure probability and statistical design of Spin-Torque Transfer Magnetic Random Access Memory (STT MRAM) array for yield enhancement

Spin-torque transfer magnetic RAM (STT MRAM) is a promising candidate for future universal memory. It combines the desirable attributes of current memory technologies such as SRAM, DRAM and flash memories. It also solves the key drawbacks of conventional MRAM technology: poor scalability and high write current. In this paper, we analyzed and modeled the failure probabilities of STT MRAM cells due to parameter variations. Based on the model, we developed an efficient simulation tool to capture the coupled electro/magnetic dynamics of spintronic device, leading to effective prediction for memory yield. We also developed a statistical optimization methodology to minimize the memory failure probability. The proposed methodology can be used at an early stage of the design cycle to enhance memory yield.