Patent ID: 8900884
Filing Date: 2014-12-02
Classification: H01L

Abstract:
1. A process for manufacturing a magnetic tunnel junction (MTJ) device comprising: depositing a seed layer having a (111) crystalline orientation; depositing on said seed layer a first perpendicular magnetic anisotropy (PMA) layer comprised of a stack of laminated layers wherein a first metal or alloy layer alternates with a second metal or alloy layer, the first PMA layer has a fcc crystal lattice structure and a (111) crystalline orientation; depositing on said first PMA layer a first magneto-resistive (MR) layer that comprises a NiFe, CoFe, or CoFeNi layer having a fcc crystal lattice structure and a (111) crystalline orientation; depositing on said first MR layer a tunnel barrier layer of magnesia; depositing on said magnesia layer a second MR layer having a fcc crystal lattice structure and a (111) crystalline orientation; depositing on said second MR layer a second PMA layer having a fcc crystal lattice structure and a (111) crystalline orientation; depositing a capping layer on said a second PMA layer; and then annealing all layers thereby causing said magnesia tunnel barrier layer to assume a (111) crystalline orientation whereby there are no transitions between different crystalline orientations for all active layers of said MTJ.