Spin-Based CMOS-Compatible Memories

With CMOS device scaling slowing down, exploring new devices' working principles becomes paramount. The electron spin, as a complement to the charge, attracts much attention. The electron spin is characterized by the two well-defined projections on a given axis and is suitable for digital applications. Magnetic tunnel junctions (MTJs) feature different resistances in parallel and antiparallel magnetization configuration and enable spin-based types of non-volatile magnetic memories. MTJs are quite CMOS compatible as they are fabricated with a CMOS-friendly process. The relative magnetization configuration is manipulated by means of a spin-transfer torque (STT) acting on the free layer. The electrically addressable non-volatile STT memory is nearing mass production for stand-alone and embedded applications. The current status and modeling approaches of state-of-the art STT and spin-orbit torque memory are briefly reviewed.