Improved YPtBi Composition in Spin Orbit Torque Devices

Patent metadata

Field	Value
Publication number	US-2025268110-A1
Application number	US-202519067574-A
Country	US
Kind code	A1
Filing date	Feb 28, 2025
Priority date	Feb 16, 2024
Publication date	Aug 21, 2025
Grant date	—

Abstract

The present disclosure generally relates to topological semi-metal (TSM) based spin-orbit torque (SOT) devices, and methods of forming a TSM layer. The TSM layer of the SOT device comprises YPtBi having a 1:1.02:1.05 stoichiometry to a 1:1.25:1.35 stoichiometry, such as a 1:1.11:1.13 stoichiometry. The TSM layer comprising about 10% less of Y compared to Pt and Bi increases the spin Hall angle (SHA) and the spin Hall conductivity. Increasing the Pt concentration ratio to greater than 1 enhances both the SHA and the spin Hall conductivity of the TSM layer by a factor of two, and further helps increase the YPtBi surface grain size, which in turn helps improve the interface spin transparency. Increasing the Bi/Y concentration ratio to greater than 1 approaching that of Pt enhances both the resistivity of the TSM layer and the effective SHA by a factor of two.

First claim

What is claimed is:

1 . A spin-orbit torque (SOT) device, comprising:
a YPtBi layer having a 1:1.02:1.05 stoichiometry to a 1:1.25:1.35 stoichiometry.

2 . The SOT device of claim 1 , wherein the YPtBi layer has a 1:1.11:1.13 stoichiometry.

3 . The SOT device of claim 1 , wherein the YPtBi layer has a (100), (111), or (110) orientation.

4 . The SOT device of claim 1 , further comprising a buffer layer disposed adjacent to the YPtBi layer.

5 . The SOT device of claim 4 , wherein the buffer layer comprises a material selected from the group consisting of:
X—Al, where X is one or more of Co, Ni, Ru, Rh, and Ir; Cr or CrX alloys, where X is one or more of Mo, Mn, Ti, Ru, and W; and RuAl, W—X, or Ta—X alloys with MgO and TiO, where X is one or more of Ta, Hf, W, V, Ti, Nb and Mo.

6 . The SOT device of claim 4 , wherein the buffer layer comprises a material selected from the group consisting of:
RuHf; Zr—X alloys, where X is one or more of Co, Cu, Ru, and Rh; Ti—Y alloys, where Y is one or more of Au, Ru, and Rh; B2 ternary A (BxC1-x) alloys; B2 binary alloys; CoZrX, where X is one or more of Ti, Fe, Ni, Nb, and Mo; two or more elements selected from the group consisting of: Ta, Hf, W, Ir, Pt, Y, Zr, Nb, Mo, Mg, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ru, Rh, and Ag; oxides of Ti, Mg, Ni, Zn, or Zr; X—N or X—C composites, where X is one or more of Sc, Ti, V, Cr, Zr, Nb, Ta, Hf, and W; and MO 2 materials, where M is one or more of Ti, Cr, Ru, Rh, Sn, Sb, Ir, CrNb, CrV, and WV.

7 . A magnetic recording head comprising the SOT device of claim 1 .

8 . A magnetic recording device comprising the magnetic recording head of claim 7 .

9 . A magnetoresistive memory comprising the SOT device of claim 1 .

10 . A spin-orbit torque (SOT) device, comprising:
a YPtBi layer, wherein a concentration of Pt and Bi is about 10% greater than a concentration of Y.

11 . The SOT device of claim 10 , wherein the YPtBi layer has a 1:1.02:1.05 stoichiometry to a 1:1.25:1.35 stoichiometry.

12 . The SOT device of claim 11 , wherein the YPtBi layer has a 1:1.11:1.13 stoichiometry.

13 . The SOT device of claim 10 , wherein the YPtBi layer has a (100), (111), or (110) orientation.

14 . A magnetic recording head comprising the SOT device of claim 10 .

15 . A magnetic recording device comprising the magnetic recording head of claim 14 .

16 . A magnetoresistive memory comprising the SOT device of claim 10 .

17 . A spin-orbit torque (SOT) device, comprising:
a YPtBi layer having a 1:1.02:1.05 stoichiometry to a 1:1.25:1.35 stoichiometry, wherein the YPtBi layer has a (100), (111), or (110) orientation; and a buffer layer disposed adjacent to the YPtBi layer.

18 . The SOT device of claim 17 , wherein the YPtBi layer has a 1:1.11:1.13 stoichiometry.

19 . The SOT device of claim 17 , wherein the buffer layer comprises a material selected from the group consisting of:
X—Al, where X is one or more of Co, Ni, Ru, Rh, and Ir; Cr or CrX alloys, where X is one or more of Mo, Mn, Ti, Ru, and W; and RuAl, W—X, or Ta—X alloys with MgO and TiO, where X is one or more of Ta, Hf, W, V, Ti, Nb and Mo.

20 . The SOT device of claim 17 , wherein the buffer layer comprises a material selected from the group consisting of:
RuHf; Zr—X alloys, where X is one or more of Co, Cu, Ru, and Rh; Ti—Y alloys, where Y is one or more of Au, Ru, and Rh; B2 ternary A (BxC1-x) alloys; B2 binary alloys; CoZrx, where X is one or more of Ti, Fe, Ni, Nb, and Mo; two or more elements selected from the group consisting of: Ta, Hf, W, Ir, Pt, Y, Zr, Nb, Mo, Mg, Sc, Ti, V, Cr, Fe, Co, Ni, Cu, Ru, Rh, and Ag; oxides of Ti, Mg, Ni, Zn, or Zr; X—N or X—C composites, where X is one or more of Sc, Ti, V, Cr, Zr, Nb, Ta, Hf, and W; and MO 2 materials, where M is one or more of Ti, Cr, Ru, Rh, Sn, Sb, Ir, CrNb, CrV, and WV.

21 . A magnetic recording head comprising the SOT device of claim 17 .

22 . A magnetic recording device comprising the magnetic recording head of claim 21 .

23 . A magnetoresistive memory comprising the SOT device of claim 17 .

Assignees

• Western Digital Tech Inc
• Inst Of Science Tokyo

Inventors

• Le Quang
• Maeda Maki
• Kagami Sho
• Pham Nam Hai

Classifications

• G11C11/161

  details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell · CPC title

• G11B5/3909

  Arrangements using a magnetic tunnel junction · CPC title

• H10N50/85 Primary

  Materials of the active region · CPC title

• G11B2005/0024

  Microwave assisted recording · CPC title

• H10N50/10 Primary

  Magnetoresistive devices · CPC title