Magnetoresistive stack with seed region and method of manufacturing the same
A magnetoresistive stack/structure and method of manufacturing same comprising wherein the stack/structure includes a seed region, a fixed magnetic region disposed on and in contact with the seed region, a dielectric layer(s) disposed on the fixed magnetic region and a free magnetic region disposed on the dielectric layer(s). In one embodiment, the seed region comprises an alloy including nickel and chromium having (i) a thickness greater than or equal to 40 Angstroms (+/−10%) and less than or equal to 60 Angstroms (+/−10%), and (ii) a material composition or content of chromium within a range of 25-60 atomic percent (+/−10%) or 30-50 atomic percent (+/−10%).
1. A magnetoresistive stack comprising:
an electrically conductive material;
a seed region disposed above the electrically conductive material, wherein the seed region includes tantalum;
a fixed magnetic region disposed above the seed region, wherein the fixed magnetic region includes a synthetic antiferromagnetic structure comprising:
a first ferromagnetic region disposed above the seed region;
a coupling layer disposed on and in contact with the first ferromagnetic region; and
a second ferromagnetic region disposed on and in contact with the coupling layer;
a first dielectric layer disposed above the second ferromagnetic region;
a free magnetic region disposed above the first dielectric layer;
a second dielectric layer disposed above the free magnetic region; and
a third magnetic region disposed above the second dielectric layer.
2. The magnetoresistive stack of claim 1 , wherein the fixed magnetic region is disposed on and in contact with the seed region.
3. The magnetoresistive stack of claim 1 , wherein the seed region further comprises iron, cobalt, palladium, platinum, nickel, ruthenium, tungsten, molybdenum, an alloy including: iron and boron, an alloy including: cobalt, iron, and boron, or a combination thereof.
4. The magnetoresistive stack of claim 1 , wherein the seed region has a thickness greater than or equal to approximately 30 Å.
5. The magnetoresistive stack of claim 1 , wherein the second dielectric layer is in contact with the free magnetic region.
6. The magnetoresistive stack of claim 5 , wherein the third magnetic region comprises iron and cobalt.
7. The magnetoresistive stack of claim 6 , further comprising a spacer region disposed above the third magnetic region.
8. The magnetoresistive stack of claim 7 , wherein the spacer region comprises ruthenium.
9. The magnetoresistive stack of claim 8 , wherein the electrically conductive material is a first electrically conductive material, and the magnetoresistive stack further comprises a second electrically conductive material disposed above the spacer region, wherein the second electrically conductive material comprises tantalum.
10. A magnetoresistive stack comprising:
an electrically conductive material;
a seed region disposed above the electrically conductive material, wherein the seed region comprises one or more of nickel, chromium, and ruthenium;
a fixed magnetic region disposed above the seed region, wherein the fixed magnetic region includes a synthetic antiferromagnetic structure comprising:
a first ferromagnetic region disposed above the seed region;
a coupling layer disposed on and in contact with the first ferromagnetic region; and
a second ferromagnetic region disposed on and in contact with the coupling layer;
a first dielectric layer disposed above the second ferromagnetic region;
a free magnetic region disposed above the first dielectric layer;
a second dielectric layer disposed above the free magnetic region; and
a third magnetic region disposed above the second dielectric layer.
11. The magnetoresistive stack of claim 10 , wherein the seed region has a thickness greater than or equal to approximately 30 Å.
12. The magnetoresistive stack of claim 10 , wherein the fixed magnetic region is disposed on and in contact with the seed region.
13. The magnetoresistive stack of claim 10 , wherein the third magnetic region comprises iron and cobalt.
14. A magnetoresistive stack comprising:
an electrically conductive material;
a seed region disposed above the electrically conductive material, wherein the seed region comprises tantalum and one or more of: nickel, chromium, ruthenium, iron, cobalt, palladium, platinum, tungsten, and molybdenum;
a fixed magnetic region disposed above the seed region, wherein the fixed magnetic region includes a synthetic antiferromagnetic structure comprising:
a first ferromagnetic region disposed above the seed region;
a coupling layer disposed on and in contact with the first ferromagnetic region; and
a second ferromagnetic region disposed on and in contact with the coupling layer;
a dielectric layer disposed above the second ferromagnetic region;
a free magnetic region disposed above the dielectric layer; and
a third magnetic region disposed above the free magnetic region.
15. The magnetoresistive stack of claim 14 , wherein the fixed magnetic region is disposed on and in contact with the seed region.
16. The magnetoresistive stack of claim 14 , wherein the dielectric layer is a first dielectric layer, and the magnetoresistive stack further comprises a second dielectric layer disposed above the free magnetic region.
17. The magnetoresistive stack of claim 14 , wherein the third magnetic region comprises iron and cobalt.
18. The magnetoresistive stack of claim 14 , further comprising a spacer region disposed above the free magnetic region, wherein the spacer region comprises ruthenium.
19. The magnetoresistive stack of claim 14 , wherein the electrically conductive material is a first electrically conductive material, and the magnetoresistive stack further comprises a second electrically conductive material disposed above the free magnetic region, wherein the second electrically conductive material comprises tantalum.
20. The magnetoresistive stack of claim 14 , wherein the seed region has a thickness greater than or equal to approximately 30 Å.