A compact model of stochastic switching in STT magnetic RAM for memory and computing

Spin-transfer torque random access memory (STT-RAM) is gaining momentum as a promising technology for high density and embedded nonvolatile memory. To enable the design of STT-RAM circuits for memory and computing, there is a need for accurate compact models capable of predicting the stochastic behavior. Here, we present a detailed model accounting for the anomalous thermal regime of switching deviating from the thermal model below 200 ns. Anomalous switching is explained by the non-linear barrier lowering of the perpendicular magnetic anisotropy (PMA). The model is validated against write error rate (WER) data and applied to the design of random number generator (RNG) and stochastic computing primitives with STT-RAM.