Maintaining Coercive Field after High Temperature Anneal for Magnetic Device Applications with Perpendicular Magnetic Anisotropy

A method of forming a magnetic memory element with a stack of layers, the method comprising:

• depositing a first lattice-matching layer on a substrate, the first lattice-matching layer including a material selected from the group consisting of Mo, Mg, Ta, Cr, W, Ru, V, and combinations thereof;
• depositing a second lattice-matching layer on the first lattice-matching layer, wherein the second lattice-matching layer has an amorphous structure when deposited on the first lattice-matching layer;
• forming an oxide layer on the second lattice-matching layer;
• depositing a free layer that contacts a top surface of the oxide layer to form a first interface which induces or enhances perpendicular magnetic anisotropy (PMA) in the free layer;
• sequentially forming a tunnel barrier, reference layer, and a hard mask on the free layer, wherein the tunnel barrier contacts a top surface of the free layer to form a second interface that induces or enhances PMA in the free layer;
• and
• annealing the stack of layers at a temperature of about 400° C. so that the second lattice-matching layer grows a body centered cubic (BCC) structure.

A method of forming a magnetic memory element with a stack of layers, the method comprising:

• depositing a first lattice-matching layer on a substrate, the first lattice-matching layer including a material selected from the group consisting of Mo, Mg, Ta, Cr, W, Ru, V, and combinations thereof;
• depositing a second lattice-matching layer having a multi-layer structure on the first lattice-matching layer, wherein the second lattice-matching layer has an amorphous structure when deposited on the first lattice-matching layer;
• forming an oxide layer on the second lattice-matching layer;
• depositing a free layer that contacts a top surface of the oxide layer to form a first interface which induces or enhances perpendicular magnetic anisotropy (PMA) in the free layer;
• sequentially forming a tunnel barrier, reference layer, and a hard mask on the free layer, wherein the tunnel barrier contacts a top surface of the free layer to form a second interface that induces or enhances PMA in the free layer;
• and
• annealing the stack of layers at a temperature of about 400° C. so that the second lattice-matching layer grows a body centered cubic (BCC) structure.