MAGNETIC ELEMENT WITH PERPENDICULAR MAGNETIC ANISOTROPY FOR HIGH COERCIVITY AFTER HIGH TEMPERATURE ANNEALING

A magnetic tunnel junction (MTJ) is disclosed wherein a free layer has an interface with a tunnel barrier and a second interface with a metal oxide layer to promote perpendicular magnetic anisotropy (PMA) therein. A diffusion barrier is formed on a side of the metal oxide layer opposite the second interface to prevent non-magnetic metals in a hard mask or electrode from migrating to the second interface and degrading free layer PMA. A second diffusion barrier may be formed between a second electrode and a reference layer. The diffusion barrier may be a single layer of SiN, TiN, TaN, Mo, or CoFeX where X is Zr, P, B, or Ta, or is a multilayer such as CoFeX/Mo wherein CoFeX contacts the metal oxide layer and Mo adjoins a hard mask. As a result, coercivity is maintained or increased in the MTJ after annealing at 400° C. for 30 minutes.