Emerging nonvolatile magnetic memory technologies

This paper reviews the development of magnetoresistive random access memory (MRAM) with an emphasis on recent developments at IBM. MRAM is unique among nonvolatile memory technologies in having high endurance (actually unlimited) and high performance, though it is not the highest density technology. In the emerging form of MRAM that scales the best, spin-torque-transfer MRAM (STT-MRAM), control of distributions will be crucial for transforming promising research results into products. These challenges are discussed, along with some options for meeting them. For lowering write currents and thus improving power and density, perpendicular magnetic anisotropy materials are vital. For helping with margins and also improving performance, a recently proposed new three-terminal device for the cell structure looks attractive.