Dual perpendicular magnetic anisotropy magnetic junction usable in spin transfer torque magnetic random access memory applications

1. A method for providing a dual magnetic junction on a substrate usable in a magnetic device, the method comprising:

providing a first pinned layer;

providing a first nonmagnetic spacer layer, the first pinned layer being between the first nonmagnetic spacer layer and the substrate;

providing a free layer, the first nonmagnetic spacer layer being between the free layer and the first pinned layer;

providing a second nonmagnetic spacer layer, the free layer being between the first and second nonmagnetic spacer layer;

providing at least one additional layer;

annealing at least the first pinned layer, the first nonmagnetic spacer layer, the free layer, the second nonmagnetic spacer layer and at least a bottom layer of the at least one additional layer at a temperature of at least three hundred and fifty degrees Celsius; and

providing a second pinned layer, the second nonmagnetic spacer layer residing between the second pinned layer and the free layer, the free layer being between the substrate and the second pinned layer, the at least one additional layer being between the second nonmagnetic spacer layer and the second pinned layer, the step of providing the second pinned layer including depositing the second pinned layer after the annealing step;

wherein the magnetic junction is configured such that the free layer is switchable between a plurality of stable magnetic states when a write current is passed through the magnetic junction.

2. The method of claim 1 wherein at least one of the free layer, the first pinned layer and the second pinned layer has a perpendicular magnetic anisotropy energy greater than an out-of-plane demagnetization energy.

3. The method of claim 2 wherein the step of providing the at least one additional layer further includes:

providing a polarization enhancement layer (PEL) between the second pinned layer and the second nonmagnetic spacer layer.

4. The method of claim 3 wherein the annealing step is performed after the step of providing the PEL.

5. The method of claim 3 wherein the PEL includes at least one of CoFeB, FeB, a bilayer including a Fe layer and a CoFeB layer, a Fe/FeB bilayer, a CoFeBTa/CoFeB bilayer, and a CoFeB/W/Fe/W/CoFeB multilayer, a half metallic material and a Heusler alloy.

6. The method of claim 3 further comprising:

providing a coupling layer between the PEL and the second pinned layer.

7. The method of claim 1 wherein the step of providing the free layer further includes:

providing at least one of a CoFeB/W/CoFeB multilayer, a CoFeB/Ta/CoFeB multilayer, a CoFeB/Hf/CoFeB multilayer, a CoFeB/V/CoFeB multilayer, a CoFeB/W/Fe/W/CoFeB multilayer, a CoFeB/(CoFeTb) i /CoFeB multilayer where i is an integer of at least one, a CoFeB/(CoFeGe) j /CoFeB multilayer where j is an integer of at least one, a Co/FeB/(CoFeGd) n /CoFeB multilayer where n is an integer of at least one.

8. The method of claim 1 wherein the free layer includes at least one amorphous bulk perpendicular magnetic anisotropy material.

9. The method of claim 8 wherein the free layer includes at least one interfacial perpendicular magnetic anisotropy material adjoining the amorphous bulk perpendicular magnetic anisotropy material.

10. The method of claim 1 wherein at least one of the first pinned layer, the second pinned layer and the free layer is a synthetic antiferromagnetic including a plurality of ferromagnetic layers interleaved with at least one nonmagnetic layer.

11. The method of claim 1 wherein the second pinned layer temperature is less than three hundred and fifty degrees Celsius during fabrication.

12. The method of claim 1 wherein the second pinned layer includes at least one of a first combination of Co and Pd, a second combination of Co and Pt, a third combination of Fe and Pt, a fourth combination of Co and Ni, a fifth combination of Tb, Co and Fe and a sixth combination of Co, Fe and B.

13. The method of claim 11 wherein the second pinned layer includes at least one of a Co/Pd multilayer, a Co/Pt multilayer, a CoPt alloy, a Fe/Pt multilayer, a Tb/CoFe multilayer, a TbCoFe alloy, and a Co/Ni multilayer.