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:
at least one alloy layer, wherein the at least one alloy layer includes nickel and chromium, and has a combined nickel content and chromium content of at least 99 atomic percent; and
at least one auxiliary layer;
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;
one or more dielectric layers disposed above the second ferromagnetic region;
a high-iron interface region disposed between the fixed magnetic region and one or more dielectric layers; and
a free magnetic region disposed above the one or more dielectric layers.
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 at least one auxiliary layer comprises iron, cobalt, palladium, platinum, nickel, tantalum, ruthenium, tungsten, molybdenum, an alloy including: iron and boron, an alloy including: cobalt, iron, and boron, or combinations 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 , further comprising a dusting layer having a thickness of approximately 1 Å to approximately 12 Å.
6. The magnetoresistive stack of claim 1 , wherein the at least one alloy layer is a first alloy layer, and the seed region further includes a second alloy layer; and
wherein the at least one auxiliary layer is in contact with the first alloy layer and the second alloy layer.
7. The magnetoresistive stack of claim 6 , wherein the second alloy layer has a combined nickel content and chromium content of at least 99 atomic percent.
8. A magnetoresistive stack comprising:
an electrically conductive material;
a seed region disposed above the electrically conductive material, wherein the seed region includes:
a first alloy layer, wherein the first alloy layer includes nickel and chromium;
at least one auxiliary layer; and
a second alloy layer, wherein the at least one auxiliary layer is in contact with the first alloy layer and the second alloy layer;
a dusting layer disposed on the seed region, wherein the dusting layer has a thickness of approximately 1 Å to approximately 12 Å;
a fixed magnetic region disposed above the dusting layer, wherein the fixed magnetic region includes a synthetic antiferromagnetic structure comprising:
a first ferromagnetic region disposed above the dusting layer;
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;
one or more dielectric layers disposed above the second ferromagnetic region; and
a free magnetic region disposed above the one or more dielectric layers.
9. The magnetoresistive stack of claim 8 , wherein the dusting layer comprises molybdenum, magnesium, iron, platinum, ruthenium, an alloy including cobalt and iron, or a combination thereof.
10. The magnetoresistive stack of claim 8 , wherein the at least one alloy layer has a thickness of approximately 10 Å to approximately 25 Å.
11. The magnetoresistive stack of claim 8 , wherein the at least one auxiliary layer comprises iron, cobalt, palladium, platinum, nickel, tantalum, ruthenium, tungsten, molybdenum, an alloy including: iron and boron, an alloy including: cobalt, iron, and boron, or combinations thereof.
12. The magnetoresistive stack of claim 8 , wherein the at least one alloy layer has a combined nickel and chromium content of at least 99 atomic percent.
13. The magnetoresistive stack of claim 8 , further comprising a high-iron interface region disposed between the fixed magnetic region and the one or more dielectric layers.
14. The magnetoresistive stack of claim 8 , wherein the second alloy layer has a combined nickel content and chromium content of at least 99 atomic percent.
15. A magnetoresistive stack comprising:
an electrically conductive material;
a seed region disposed above the electrically conductive material, wherein the seed region includes:
a plurality of alloy layers, wherein at least one alloy layer includes nickel and chromium, and has a combined nickel content and chromium content of at least 99 atomic percent; and
at least one auxiliary layer, wherein the at least one auxiliary layer comprises iron, cobalt, palladium, platinum, nickel, tantalum, ruthenium, tungsten, molybdenum, an alloy including: iron and boron, an alloy including: cobalt, iron, and boron, or combinations thereof;
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;
one or more dielectric layers disposed above the second ferromagnetic region; and
a free magnetic region disposed above the one or more dielectric layers.
16. The magnetoresistive stack of claim 15 , further comprising a dusting layer having a thickness of approximately 1 Å to approximately 12 Å.
17. The magnetoresistive stack of claim 16 , wherein the dusting layer comprises molybdenum, magnesium, iron, platinum, ruthenium, an alloy including cobalt and iron, or a combination thereof.
18. The magnetoresistive stack of claim 16 , wherein the dusting layer is disposed between the seed region and the fixed magnetic region.
19. The magnetoresistive stack of claim 15 , wherein the fixed magnetic region is disposed on and in contact with the seed region.
20. The magnetoresistive stack of claim 15 , further comprising a high-iron interface region disposed between the fixed magnetic region and the one or more dielectric layers.