SPIN-ORBIT-TORQUE MAGNETIZATION ROTATIONAL ELEMENT, SPIN-ORBIT-TORQUE MAGNETORESISTANCE EFFECT ELEMENT, AND MAGNETIC MEMORY

• US 20200136023A1
• Filed: 09/23/2019
• Published: 04/30/2020
• Est. Priority Date: 10/31/2018
• Status: Active Grant

• Current Assignee: TDK Corporation
• Original Assignee: TDK Corporation
• Inventors: TSUMITA, Atsushi, SHIOKAWA, Yohei, SASAKI, Tomoyuki
• Granted Patent: US 11,056,641 B2
• Time in Patent Office: Days
• CPC Class Codes: G11C 11/155 with cylindrical configuration
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: G11C 11/1659 Cell access
• CPC Class Codes: G11C 11/1675 Writing or programming circuits or methods
• CPC Class Codes: G11C 11/18 using Hall-effect devices
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H01F 10/329 Spin-exchange coupled multilayers wherein the magnetisation of the free layer is switched by a spin-polarised current, e.g. spin torque effect
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/80 Constructional details
• CPC Class Codes: H10N 50/85 Magnetic active materials
• CPC Class Codes: H10N 52/80 Constructional details

Abstract

A spin-orbit-torque magnetization rotational element includes: a first ferromagnetic layer; and a spin-orbit torque wiring in which a first surface faces the first ferromagnetic layer and a long axis extends in a first direction when viewed in plan view from a lamination direction of the first ferromagnetic layer, wherein the first surface spreads along a reference plane orthogonal to the lamination direction of the first ferromagnetic layer, the spin-orbit torque wiring contains a first virtual cross-section which passes through a first end of the first ferromagnetic layer in the first direction and is orthogonal to the first direction and a second virtual cross-section which passes through a second end of the first ferromagnetic layer in the first direction and is orthogonal to the first direction, and an area of the first virtual cross-section is different from an area of the second virtual cross-section.

Claims

1. A spin-orbit-torque magnetization rotational element, comprising:

a first ferromagnetic layer; and

a spin-orbit torque wiring in which a first surface faces the first ferromagnetic layer and a long axis extends in a first direction when viewed in plan view from a lamination direction of the first ferromagnetic layer,

wherein the first surface spreads along a reference plane orthogonal to the lamination direction of the first ferromagnetic layer,

the spin-orbit torque wiring contains a first virtual cross-section which passes through a first end of the first ferromagnetic layer in the first direction and is orthogonal to the first direction and a second virtual cross-section which passes through a second end of the first ferromagnetic layer in the first direction and is orthogonal to the first direction, and

an area of the first virtual cross-section is different from an area of the second virtual cross-section.

2. The spin-orbit-torque magnetization rotational element according to claim 1,

wherein widths of the spin-orbit torque wiring in a second direction orthogonal to the first direction are different in the first virtual cross-section and the second virtual cross-section when viewed in plan view from the lamination direction of the first ferromagnetic layer.

3. The spin-orbit-torque magnetization rotational element according to claim 1,

wherein thicknesses of the spin-orbit torque wiring are different in the first virtual cross-section and the second virtual cross-section.

4. The spin-orbit-torque magnetization rotational element according to claim 1,

wherein the first ferromagnetic layer has a narrow width portion whose width in the second direction orthogonal to the first direction is locally narrower between the first end and the second end when viewed in plan view from the lamination direction of the first ferromagnetic layer.

5. The spin-orbit-torque magnetization rotational element according to claim 4,

wherein a plurality of the narrow width portions are provided between the first end and the second end.

6. A spin-orbit-torque magnetoresistance effect element, comparing:

the spin-orbit-torque magnetization rotational element according to claim 1;

a magnetization fixed layer located on a side of the first ferromagnetic layer opposite to the spin-orbit torque wiring; and

a first non-magnetic layer located between the magnetization fixed layer and the first ferromagnetic layer.

7. The spin-orbit-torque magnetoresistance effect element according to claim 6, further comprising:

a magnetic field application mechanism for applying a magnetic field from the first end toward the second end when the area of the first virtual cross-section is larger than the area of the second virtual cross-section and applying a magnetic field from the second end toward the first end when the area of the first virtual cross-section is smaller than the area of the second virtual cross-section.

8. The spin-orbit-torque magnetoresistance effect element according to claim 6,

wherein the magnetization fixed layer has a second ferromagnetic layer, a second non-magnetic layer, and a third ferromagnetic layer in this order from a position close to the first ferromagnetic layer,

a product of a saturation magnetization and a volume of the second ferromagnetic layer is larger than a product of a saturation magnetization and a volume of the third ferromagnetic layer,

orientation directions of the magnetizations in the second ferromagnetic layer and the third ferromagnetic layer are opposite to each other, and

the magnetization fixed layer applies a magnetic field from the second end toward the first end to the first ferromagnetic layer.

9. The spin-orbit-torque magnetoresistance effect element according to claim 8,

wherein the spin-orbit torque wiring has a spin Hall angle which has a positive polarity, and

the spin-orbit torque wiring mainly includes any metal element selected from the group consisting of those of Groups 8, 9, 10, 11, and 12.

10. The spin-orbit-torque magnetoresistance effect element according to claim 6,

wherein the magnetization fixed layer has a second ferromagnetic layer, a second non-magnetic layer, and a third ferromagnetic layer in this order from a position close to the first ferromagnetic layer,

a product of a saturation magnetization and a volume of the second ferromagnetic layer is smaller than a product of a saturation magnetization and a volume of the third ferromagnetic layer,

orientation directions of the magnetizations of the second ferromagnetic layer and the third ferromagnetic layer are opposite to each other, and

the magnetization fixed layer applies a magnetic field from the first end toward the second end to the first ferromagnetic layer.

11. The spin-orbit-torque magnetoresistance effect element according to claim 10,

wherein the spin-orbit torque wiring has a spin Hall angle which has a negative polarity, and

the spin-orbit torque wiring mainly includes any metal element selected from the group consisting of those of Groups 3, 4, 5, and 6.

12. A magnetic memory, comprising:

a plurality of the spin-orbit-torque magnetoresistance effect elements according claim 6.

13. The spin-orbit-torque magnetization rotational element according to claim 2,

wherein thicknesses of the spin-orbit torque wiring are different in the first virtual cross-section and the second virtual cross-section.

14. The spin-orbit-torque magnetization rotational element according to claim 2,

wherein the first ferromagnetic layer has a narrow width portion whose width in the second direction orthogonal to the first direction is locally narrower between the first end and the second end when viewed in plan view from the lamination direction of the first ferromagnetic layer.

15. The spin-orbit-torque magnetization rotational element according to claim 3,

wherein the first ferromagnetic layer has a narrow width portion whose width in the second direction orthogonal to the first direction is locally narrower between the first end and the second end when viewed in plan view from the lamination direction of the first ferromagnetic layer.

16. The spin-orbit-torque magnetization rotational element according to claim 13,

wherein the first ferromagnetic layer has a narrow width portion whose width in the second direction orthogonal to the first direction is locally narrower between the first end and the second end when viewed in plan view from the lamination direction of the first ferromagnetic layer.

17. A spin-orbit-torque magnetoresistance effect element, comparing:

the spin-orbit-torque magnetization rotational element according to claim 2;

a magnetization fixed layer located on a side of the first ferromagnetic layer opposite to the spin-orbit torque wiring; and

a first non-magnetic layer located between the magnetization fixed layer and the first ferromagnetic layer.

18. A spin-orbit-torque magnetoresistance effect element, comparing:

spin-orbit-torque magnetization rotational element according to claim 3;

a magnetization fixed layer located on a side of the first ferromagnetic layer opposite to the spin-orbit torque wiring; and

a first non-magnetic layer located between the magnetization fixed layer and the first ferromagnetic layer.

19. A spin-orbit-torque magnetoresistance effect element, comparing:

the spin-orbit-torque magnetization rotational element according to claim 4;

a magnetization fixed layer located on a side of the first ferromagnetic layer opposite to the spin-orbit torque wiring; and

a first non-magnetic layer located between the magnetization fixed layer and the first ferromagnetic layer.

20. A spin-orbit-torque magnetoresistance effect element, comparing:

the spin-orbit-torque magnetization rotational element according to claim 5;

a magnetization fixed layer located on a side of the first ferromagnetic layer opposite to the spin-orbit torque wiring; and

a first non-magnetic layer located between the magnetization fixed layer and the first ferromagnetic layer.