Patent ID: 8456893

Claim:
A method of forming an MTJ element on a substrate in a magnetic device, comprising: (a) forming a pinned layer in a MTJ stack of layers wherein the pinned layer has an AP2/coupling layer/AP1 configuration in which the AP2layer is formed on an AFM layer and the AP1 layer is made of amorphous CoFeB; (b) forming a crystalline MgO tunnel barrier on the amorphous CoFeB AP1 pinned layer by a method that comprises a radical oxidation (ROX) or natural oxidation (NOX) of a Mg layer; (c) forming an amorphous CoFeB free layer on the MgO barrier layer, the free layer has a composition in which an atomic % of each of Co, Fe, and B is equivalent to that of the AP1 layer; and (d) forming a composite capping layer on said amorphous CoFeB free layer wherein said composite capping layer is comprised of a lower layer made of a metal having an oxidation potential greater than that of Co, Fe, and Ta to provide a high oxygen gettering capability, and an upper layer.