Would you like to see your presentation here, made available to a global audience of researchers?
Add your own presentation or have us affordably record your next conference.
Writing using spin-orbit torque (SOT) has been widely investigated in the field of magnetic random-access memory (MRAM) as it provides several advantages over Spin transfer torque (STT) based writing, including a much faster writing speed, better writing endurance, and protection to MgO from oxide breakdown due to a large current flowing across it during STT writing process, among others. Heavy metal(HM)/CoFeB/MgO is the core of this SOT-MRAM structure. The heterostructure consisting of Ta as the spin current source and CoFeB/MgO as the perpendicular magnetic anisotropy (PMA) material is the most researched structure owing to the high tunneling magneto-resistance ratio. However, Ta is difficult to be integrated into the CMOS process due to its poor thermal stability against annealing at temperatures greater than 350 °C. Currently, β-Tungsten (W) is the only heavy metal with CoFeB/MgO system, which can provide both thermal stability and spin-orbit torque switching simultaneously. Nevertheless, achieving a high resistive β phase of W is a challenging task, and the high resistivity of β-W makes the devices susceptible to Joule's heating. Here, we report another material Rhenium (Re) capable of providing thermally stable PMA up to temperature 425 °C with a perpendicular anisotropic field greater than 5000 Oe; Re possesses a spin hall angle (θSH) of 0.065 ± 0.003 and spin-orbit torque switching can be achieved with current density around 1.36×1011 A/m2. Our findings pave a new avenue for the material design of perpendicular SOT-based MRAM.
