MgO Based Magnetic Tunnel Junctions With Co$_{20}$Fe$_{60}$B$_{20}$ Sensing Layer for Magnetic Field Sensors

Magnetic tunnel junctions for magnetic field sensor by using CoFeB sensing layer capped with MgO film

“…To obtain these characteristics and to suppress hysteresis in magnetoresistance (MR) curves, MTJs with spin-valve-type structures of CoFeB sensing layers showing perpendicular magnetic anisotropy (PMA) have been investigated. [1][2][3] We have also reported that the MTJs of CoFeB sensing layers of various thicknesses, which show PMA at the MgO/CoFeB interface, 4 can suppress the hysteresis. 3 Ta capping layers have been applied to these reported MTJs, in which CoFeB sensing layers have only one interface with MgO films, and the characteristics of the MTJs of the sensing layers showing partial PMA strongly depend on the thickness of the sensing layer.…”

“…[1][2][3] We have also reported that the MTJs of CoFeB sensing layers of various thicknesses, which show PMA at the MgO/CoFeB interface, 4 can suppress the hysteresis. 3 Ta capping layers have been applied to these reported MTJs, in which CoFeB sensing layers have only one interface with MgO films, and the characteristics of the MTJs of the sensing layers showing partial PMA strongly depend on the thickness of the sensing layer. Therefore, one of the problems in sensing layers showing partial PMA is controlling the thickness.…”