Spin transfer torque tunneling magnetoresistive device having a laminated free layer with perpendicular magnetic anisotropy

摘要

A spin transfer torque magnetic junction includes a magnetic reference layer structure with magnetic anisotropy perpendicular to a substrate plane. A laminated magnetic free layer comprises at least three sublayers (e.g. sub-layers of CoFeB, CoPt, FePt, or CoPd) having magnetic anisotropy perpendicular to the substrate plane. Each such sublayer is separated from an adjacent one by a dusting layer (e.g. tantalum). An insulative barrier layer (e.g. MgO) is disposed between the laminated free layer and the magnetic reference layer structure. The spin transfer torque magnetic junction includes conductive base and top electrodes, and a current polarizing structure that has magnetic anisotropy parallel to the substrate plane. In certain embodiments, the current polarizing structure may also include a non-magnetic spacer layer (e.g. MgO, copper, etc).