Reduced Thermal Variation of Perpendicular Magnetic Anisotropy in Magnetically Stiffened Dual-W Composite Storage Layer for Spin-Transfer-Torque Magnetic Random-Access Memory

This article reports a type of magnetic tunnel junction (MTJ) with an expanded middle layer, for spin-transfer-torque magnetic random-access memory (STT-MRAM). This data-storage layer of the form Fe-Co-B/W/Co/W/Fe-Co-B sandwiches a ferromagnet with high exchange stiffness between two tungsten films, and thus is much less sensitive to temperature than that in a conventional MTJ. Such a storage layer is promising for spintronic memory that must operate across a wide range of temperatures, as in automobile applications.