Thermally tolerant perpendicular magnetic anisotropy coupled elements for spin-transfer torque switching device

摘要

Perpendicular magnetic anisotropy (PMA) type magnetic random access memory cells are constructed with a composite PMA layer to provide a magnetic tunnel junction (MTJ) with an acceptable thermal barrier. A PMA coupling layer is deposited between a first PMA layer and a second PMA layer to form the composite PMA layer. The composite PMA layer may be incorporated in PMA type MRAM cells or in-plane type MRAM cells.

主权项

1. A magnetic tunnel junction (MTJ) comprising:
a reference layer; a composite perpendicular magnetic anisotropy (PMA) layer including a first PMA free layer, a PMA assist layer, and a PMA coupling layer between the first PMA free layer and the PMA assist layer, the coupling layer abutting the first PMA free layer and the PMA assist layer; a tunnel barrier layer between the reference layer and the composite PMA layer; a longitudinal magnetic anisotropy (LMA) free layer between the tunnel barrier layer and the composite PMA layer; a spacer layer between the LMA free layer and the composite PMA layer; a PMA promotion layer coupled to the composite PMA layer, the PMA promotion layer abutting the PMA assist layer; and a hard mask layer abutting the PMA promotion layer.