Spin-transfer torque magnetoresistive random access memory technology status and future directions

Spin-transfer torque magnetoresistive random access memory (STT-MRAM) is a non-volatile memory technology with a unique combination of speed, endurance, density and ease of fabrication, which has enabled it to recently replace embedded Flash as the embedded non-volatile memory of choice for advanced applications, including automotive microcontroller units. In this Review, we describe the working principles of STT-MRAM, and provide a brief history of its development. We then discuss the requirements, product status and outlook for four key STT-MRAM applications: stand-alone, embedded non-volatile memory, non-volatile working memory and last-level cache. Finally, we review potential future directions beyond STT-MRAM, including spin–orbit torque MRAM (SOT-MRAM) and voltage control of magnetic anisotropy MRAM (VCMA-MRAM), with an emphasis on their technological potential.