Film and method for BiSbX (012) texture for SOT devices
The present disclosure generally relates to spin-orbit torque (SOT) device comprising a bismuth antimony (BiSb) layer. The SOT device comprises a seed layer and a BiSb layer having a (012) orientation. The seed layer comprises at least one of an amorphous/nanocrystalline material with a nearest neighbor x-ray diffraction peak with a d-spacing in the range of about 2.02 Å to about 2.20 Å; a polycrystalline material having a (111) orientation and an a-axis of about 3.53 Å to about 3.81 Å; and a polycrystalline material having a cubic (100) or tetragonal (001) orientation and an a-axis of about 4.1 Å to about 4.7 Å. When the seed layer comprises an amorphous material or a polycrystalline material having a (111), the BiSb layer is doped, and the seed layer has a lower a/c ratio than when the seed layer comprises polycrystalline material having a cubic (100) or tetragonal (001) orientation.
1 . A spin-orbit torque (SOT) device, comprising:
a substrate;
a seed layer disposed over the substrate, the seed layer comprising a (100) Heusler alloy with a-axis in a range of about 5.8 Å to about 6.6 Å;
a ferromagnetic layer disposed on the seed layer;
a barrier layer disposed on the ferromagnetic layer, the barrier layer comprising an oxide, nitride, or carbide material;
a bismuth antimony (BiSb) layer disposed on the barrier layer, the BiSb layer having a (012) orientation;
an interlayer disposed on the BiSb layer; and
a cap layer disposed on the interlayer, the cap layer comprising NiFeGe, NiFeTaN, or oxidized NiFeTaN, or comprising a multi-layer structure of NiFeGe/Ru, where “/” denotes separate layers of the multi-layer structure.
2 . The SOT device of claim 1 , wherein the BiSb layer is doped with one or more of: B, N, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Ge, Mo, Ru, Y, Zr, Hf, Ta, W, and Ag.
3 . The SOT device of claim 1 , wherein the seed layer further comprises a texturing layer.
4 . The SOT device of claim 3 ,
wherein the ferromagnetic layer is disposed on the texturing layer.
5 . A magnetic recording head comprising the SOT device of claim 1 .
6 . A magnetic recording device comprising the magnetic recording head of claim 5 .
7 . A magneto-resistive memory comprising the SOT device of claim 1 .
8 . The SOT device of claim 1 , wherein the barrier layers comprises MgO or MgTiO.
9 . A spin-orbit torque (SOT) device, comprising:
a substrate;
a seed layer disposed over the substrate, the seed layer comprising a (100) Heusler alloy with a-axis in a range of about 5.8 Å to about 6.6 Å;
a first barrier layer disposed in contact with the seed layer, the first barrier layer comprising an oxide, nitride, or carbide material;
a ferromagnetic layer disposed in contact with the first barrier layer;
a second barrier layer disposed in contact with the ferromagnetic layer, the second barrier layer comprising an oxide, nitride, or carbide material;
a bismuth antimony (BiSb) layer disposed in contact with the second barrier layer, the BiSb layer having a (012) orientation; and
a cap layer disposed over the BiSb layer.
10 . The SOT device of claim 9 , wherein the BiSb layer has an Sb concentration of about 10 to about 50 atomic percent.
11 . The SOT device of claim 9 , wherein the BiSb layer is doped with one or more of: B, N, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Ge, Mo, Ru, Y, Zr, Hf, Ta, W, and Ag.
12 . The SOT device of claim 9 , wherein the BiSb layer has an a/c ratio of about 0.381 or greater.
13 . A magnetic recording head comprising the SOT device of claim 9 .
14 . A magnetic recording device comprising the magnetic recording head of claim 13 .
15 . A magneto-resistive memory comprising the SOT device of claim 9 .
16 . The SOT device of claim 9 , wherein the first and second barrier layers each individually comprise MgO or MgTiO.
17 . The SOT device of claim 9 , wherein the cap layer comprises NiFeGe, NiFeTaN, or oxidized NiFeTaN, or comprising a multi-layer structure of NiFeGe/Ru, where “/” denotes separate layers of the multi-layer structure.
18 . A spin-orbit torque (SOT) device, comprising:
a substrate;
a seed layer disposed over the substrate, the seed layer comprising a (100) Heusler alloy with a-axis in a range of about 5.8 Å to about 6.6 Å;
a first barrier layer disposed over the seed layer, the first barrier layer comprising an oxide, nitride, or carbide material;
a bismuth (BiSb) layer disposed on the first barrier layer, the BiSb layer having a (012) orientation;
a second barrier layer disposed on the BiSb layer, the second barrier layer comprising an oxide, nitride, or carbide material;
a ferromagnetic layer disposed on the second barrier layer; and
a cap layer disposed over the ferromagnetic layer, the cap layer comprising ene or more materials selected from the group consisting of: NiFeGe, NiFeTaN, and/or oxidized NiFeTaN, or comprising a multi-layer structure selected from the group consisting of NiFeGe/Ru NiFeGe/Ru, where “/” denotes separate layers of the multi-layer structure.
19 . The SOT device of claim 18 , wherein the BiSb layer is doped with one or more of: B, N, Al, Si, Ti, V, Cr, Fe, Ni, Cu, Ge, Mo, Ru, Y, Zr, Hf, Ta, W, and Ag.
20 . The SOT device of claim 18 , wherein the seed layer further comprises a texturing layer.
21 . The SOT device of claim 18 , wherein the BiSb layer has an Sb concentration of about 10 to about 50 atomic percent.
22 . The SOT device of claim 18 , wherein the BiSb layer has an a/c ratio of about 0.381 or greater.
23 . A magnetic recording head comprising the SOT device of claim 18 .
24 . A magnetic recording device comprising the magnetic recording head of claim 23 .
25 . A magneto-resistive memory comprising the SOT device of claim 23 .
26 . The SOT device of claim 18 , wherein the first and second barrier layers each individually comprise MgO or MgTiO.