Spin-orbit torque device and manufacturing method thereof

Patent metadata

Field	Value
Publication number	US-12439828-B2
Application number	US-202217677078-A
Country	US
Kind code	B2
Filing date	Feb 22, 2022
Priority date	Sep 30, 2021
Publication date	Oct 7, 2025
Grant date	Oct 7, 2025

Abstract

Disclosed herein is a spin-orbit torque device including a lower ferromagnetic layer, a non-magnetic layer bonded to the lower ferromagnetic layer, and an upper ferromagnetic layer bonded to the non-magnetic layer, wherein a magnetization orientation of the lower ferromagnetic layer is randomly distributed. According to the present disclosure, it is possible to provide a magnetic memory device which cannot be physically duplicated and has reconfigurability using a spin-orbit torque.

First claim

The invention claimed is:

1. A spin-orbit torque for a physically unclonable functions (PUF) device, comprising:
a lower ferromagnetic layer;
a non-magnetic layer bonded to the lower ferromagnetic layer; and
an upper ferromagnetic layer bonded to the non-magnetic layer;
wherein the lower ferromagnetic layer has horizontal anisotropy and the upper ferromagnetic layer has anisotropy perpendicular to a plane direction of the upper ferromagnetic layer; and
wherein a ratio of magnetic domains with a magnetization direction of +x and magnetic domains with a magnetization direction of-x formed within the lower ferromagnetic layer is 50:50.

2. The spin-orbit torque device of claim 1 , wherein a switching polarity of the upper ferromagnetic layer is determined according to a random magnetization orientation of the lower ferromagnetic layer.

3. The spin-orbit torque device of claim 2 , wherein each of the upper ferromagnetic layer and the lower ferromagnetic layer includes any one among a CoFeB alloy, a CoFe alloy, and a NiFe alloy.

4. The spin-orbit torque device of claim 3 , wherein the non-magnetic layer includes any one of titanium (Ti) and tantalum (Ta).

5. A spin-orbit torque for a physically unclonable functions (PUF) device, comprising:
an antiferromagnetic layer;
a lower ferromagnetic layer bonded to the antiferromagnetic layer;
a non-magnetic layer bonded to the lower ferromagnetic layer; and
an upper ferromagnetic layer which is bonded to the non-magnetic layer and which has perpendicular anisotropy;
wherein a ratio of magnetic domains with a magnetization direction of +x and magnetic domains with a magnetization direction of-x formed within the lower ferromagnetic layer is 50:50; and
wherein exchange coupling anisotropy is formed between the antiferromagnetic layer and the lower ferromagnetic layer.

6. The spin-orbit torque device of claim 5 , wherein the lower ferromagnetic layer is demagnetized.

7. The spin-orbit torque device of claim 6 , wherein a switching polarity of the upper ferromagnetic layer is determined according to a random magnetization orientation of the lower ferromagnetic layer.

8. The spin-orbit torque device of claim 7 , wherein:
each of the upper ferromagnetic layer and the lower ferromagnetic layer includes any one among a CoFeB alloy, a CoFe alloy, and a NiFe alloy; and
the antiferromagnetic layer includes any one of IrMn and PtMn.

9. A method of manufacturing a spin-orbit torque device, comprising:
preparing the spin-orbit torque device of claim 1 ; and
demagnetizing the lower ferromagnetic layer of the spin-orbit torque.

10. The method of claim 9 , wherein the demagnetizing of the lower ferromagnetic layer includes:
heating the spin-orbit torque device; and
applying a magnetic field to the spin-orbit torque device.

11. The method of claim 10 , wherein the heating of the spin-orbit torque device includes heating the lower ferromagnetic layer at a temperature that is greater than or equal to a Neél temperature of the lower ferromagnetic layer.

12. The method of claim 11 , wherein the applying of the magnetic field includes alternating and applying a magnetic field to the spin-orbit torque device in an orientation opposite to a forward orientation by gradually reducing a magnitude of the magnetic field.

Assignees

• Hyundai Motor Co Ltd
• Kia Corp
• Korea Advanced Inst Sci & Tech

Inventors

• Lee Ji-Sung
• Kwon Joon-Hyun
• Noh Su-Jung
• Lee Han-Saem
• Park Byong-Guk
• Kang Jaimin
• Kim Jeong-Mok
• Lee Soogil

Classifications

• G11C11/1695

  Protection circuits or methods · CPC title

• G11C11/1675

  Writing or programming circuits or methods · CPC title

• H10B61/00

  Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices · CPC title

• H01F10/329

  Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect · CPC title

• H01F10/3286

  Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy · CPC title