Fast simulation of spin transfer torque devices in a general purpose TCAD device simulator

Abstract

We present integrated simulation of spin-transfer torque (STT) devices within the framework of a general purpose TCAD device simulator. A fast Airy function based approach is used to calculate spin and charge transport through magnetic tunnel junctions (MTJ). This enables direct mixed mode simulation of STT devices in a circuit environment - consisting of physical TCAD device models, SPICE-like compact models or a combination thereof - without first constructing a response surface model for the STT device. This was used to simulate a 4T-2MTJ non-volatile SRAM cell. For device interactions that are not captured in a circuit picture, STT and conventional devices may be combined in a single simulation geometry. Using an explicit exchange term in the Landau-Lifshitz-Gilbert equation allows capturing some aspects of spin dynamics beyond the macro-spin approximation.