Spin orbit torque (SOT) memory devices with enhanced magnetic anisotropy and methods of fabrication
A perpendicular spin orbit torque (SOT) memory device includes an electrode having a spin orbit coupling material and a perpendicular magnetic tunnel junction (pMTJ) device on a portion of the electrode. The pMTJ device includes a free magnet, a fixed magnet and a tunnel barrier layer in between, where at least one of the fixed magnet or the free magnet includes two magnetic layers and a spacer layer comprising tungsten in between.
1. A three-terminal perpendicular spin orbit torque (pSOT) memory device, comprising:
a first electrode, comprising a spin orbit torque material;
a first conductive interconnect coupled to a first end of the first electrode;
a second conductive interconnect coupled to a second end of the first electrode, the second end opposite the first end;
a material layer stack adjacent to the first electrode, the material layer stack comprising:
a free magnet above the first electrode;
a fixed magnet above the free magnet, wherein at least one of the free magnet or the fixed magnet comprises two magnetic layers and a spacer layer comprising tungsten therebetween;
a tunnel barrier between the free magnet and the fixed magnet; and
a second electrode coupled with the fixed magnet; and
a contact coupled to the second electrode.
2. The pSOT memory device of claim 1 , wherein the free magnet comprises:
a first free magnet;
a second free magnet, wherein the first free magnet is ferromagnetically coupled with the second free magnet; and
the spacer layer between the first free magnet and the second free magnet.
3. The pSOT memory device of claim 2 , wherein the spacer layer has a thickness between 0.05 nm and 0.3 nm.
4. The pSOT memory device of claim 2 , wherein the first free magnet has a thickness that is greater than a thickness of the second free magnet, and wherein the first free magnet and the second free magnet have a combined total thickness of less than 5 nm.
5. The pSOT memory device of claim 2 , wherein the first free magnet comprises at least one of cobalt, iron or boron and wherein the first free magnet is on the first electrode.
6. The pSOT memory device of claim 5 , wherein the second free magnet comprises at least one of cobalt, iron, or boron.
7. The pSOT memory device of claim 1 , wherein the fixed magnet structure comprises:
a first fixed magnet;
a second fixed magnet, wherein the second fixed magnet is ferromagnetically coupled with the first fixed magnet; and
the spacer layer between the first fixed magnet and the second fixed magnet.
8. The pSOT memory device of claim 7 , wherein the spacer layer has a thickness between 0.05 nm and 0.3 nm.
9. The pSOT memory device of claim 7 , wherein the first fixed magnet has a thickness between 0.5 nm and 2.5 nm.
10. The pSOT memory device of claim 7 , wherein the second fixed magnet has a thickness between 0.5 nm and 2.5 nm.
11. The pSOT memory device of claim 7 , wherein the first fixed magnet and the second fixed magnet comprise at least one of cobalt, boron, or iron.
12. The pSOT memory device of claim 2 , wherein the spacer layer is a first spacer layer and the fixed magnet comprises:
a first fixed magnet;
a second fixed magnet, wherein the second fixed magnet is ferromagnetically coupled with the first fixed magnet; and
a second spacer layer comprising tungsten between the first fixed magnet and the second fixed magnet.
13. The pSOT memory device of claim 1 , further comprising a synthetic anti-ferromagnet (SAF) between the fixed magnet and the second electrode.
14. A system comprising:
a processor; and
a three-terminal perpendicular spin orbit torque (pSOT) memory device coupled with the drain contact, the three-terminal pSOT memory device comprising:
a first electrode, comprising a spin orbit torque material;
a first conductive interconnect coupled to a first end of the first electrode;
a second conductive interconnect coupled to a second end of the first electrode, the second end opposite the first end;
a material layer stack adjacent to the first electrode, the material layer stack comprising:
a free magnet above the first electrode;
a fixed magnet above the free magnet, wherein at least one of the free magnet or the fixed magnet comprises two magnetic layers and a spacer layer comprising tungsten therebetween;
a tunnel barrier between the free magnet and the fixed magnet; and
a second electrode coupled with the fixed magnet; and
a contact coupled to the second electrode.
15. The system of claim 14 , further comprising a battery coupled to at least one of the processor or memory.
16. The system of claim 14 , wherein the free magnet comprises:
a first free magnet;
a second free magnet, wherein the first free magnet is ferromagnetically coupled with the second free magnet; and
the spacer layer between the first free magnet and the second free magnet.
17. The system of claim 16 , wherein the spacer layer has a thickness between 0.05 nm and 0.3 nm.
18. The system of claim 16 , wherein the first free magnet has a thickness that is greater than a thickness of the second free magnet, and wherein the first free magnet and the second free magnet have a combined total thickness of less than 5 nm.
19. The system of claim 16 , wherein the first free magnet comprises at least one of cobalt, iron, or boron, and wherein the first free magnet is on the first electrode.
20. The system of claim 14 , wherein the pSOT memory device further comprises a synthetic anti-ferromagnet (SAF) between the fixed magnet and the second electrode.