Interfacial engineering of SOT-MRAM to modulate atomic diffusion and enable PMA stability >400 °C

We report our work on the optimization of W/CoFeB/MgO structures to fulfill perpendicular magnetic anisotropy (PMA) requirements in the production of SOT-MRAM. By optimizing the natural oxidization process of deposited Mg layer and introducing different dust layers at W/CoFeB and CoFeB/MgO interfaces, PMA of W/CoFeB/MgO structures can be enhanced by about 100%, which is much higher than that in Ta-based structures. The origin of this PMA enhancement was further confirmed by transmission electron microscopy investigations. The corresponding SOT switching efficiency and current-induced effective fields were also investigated.