Patent ID: 7630177

Claim:
A tunnel magnetoresistive (TMR) device comprising: a pinned ferromagnetic layer having a magnetization substantially prevented from rotation in the presence of an applied magnetic field; an insulating tunnel barrier layer on the pinned layer; and a free ferromagnetic stack on the tunnel barrier layer and having at least one magnetization substantially free to rotate in the presence of an applied magnetic field, the free ferromagnetic stack having an upper free sublayer, a lower free sublayer, and a spacer layer disposed between the free sublayers, the free sublayers being in contact with each other through opposed shoulders, the spacer layer not extending completely to the ends of the lower free sublayer, wherein the shoulders are made of the same material as the free sublayers, at least one shoulder defining a thickness that is the same as a thickness defined by each of the free sublayers, the at least one shoulder defining a single constant thickness and no other thicknesses and the free sublayers likewise defining respective single constant thicknesses and no other thicknesses, the at least one shoulder not being interposed between any free sublayer and the spacer layer.