MAGNETORESISTIVE ELEMENT

• US 20090091863A1
• Filed: 10/01/2008
• Published: 04/09/2009
• Est. Priority Date: 10/03/2007
• Status: Active Grant

• Current Assignee: Kioxia Corporation
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Asao, Yoshiaki, Hosotani, Keiji
• Granted Patent: US 8,604,569 B2
• Time in Patent Office: Days
• US Class Current: 360/324.2
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11C 11/161 details concerning the memory cell structure, e.g. the layers of the ferromagnetic memory cell
• CPC Class Codes: H01F 10/1933 Perovskites
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3263 the exchange coupling being symmetric, e.g. for dual spin valve, e.g. NiO/Co/Cu/Co/Cu/Co/NiO
• CPC Class Codes: H01F 10/3286 Spin-exchange coupled multilayers having at least one layer with perpendicular magnetic anisotropy
• CPC Class Codes: H10B 61/22 of the field-effect transistor [FET] type
• CPC Class Codes: H10N 50/10 Magnetoresistive devices
• CPC Class Codes: H10N 50/85 Magnetic active materials

Abstract

A magnetoresistive element includes a first electrode layer, a first fixed layer provided on the first electrode layer and having a fixed magnetization direction, a first intermediate layer provided on the first fixed layer and made of a metal oxide, a free layer provided on the first intermediate layer and having a variable magnetization direction, and a second electrode layer provided on the free layer. At least one of the first electrode layer and the second electrode layer contains a conductive metal oxide.

Claims

1. A magnetoresistive element comprising:

a first electrode layer;

a first fixed layer provided on the first electrode layer and having a fixed magnetization direction;

a first intermediate layer provided on the first fixed layer and made of a metal oxide;

a free layer provided on the first intermediate layer and having a variable magnetization direction; and

a second electrode layer provided on the free layer,

wherein at least one of the first electrode layer and the second electrode layer contains a conductive metal oxide.

2. The magnetoresistive element according to claim 1, wherein the first intermediate layer is made of magnesium oxide or aluminum oxide.

3. The magnetoresistive element according to claim 1, wherein the conductive metal oxide is an NaCl-type metal oxide, a spinel-type metal oxide, a perovskite-ReO₃-type metal oxide, a corundum-type metal oxide or a rutile-MoO₂-type metal oxide.

4. The magnetoresistive element according to claim 1, further comprising:

a second intermediate layer provided on the free layer and made of a nonmagnetic material; and

a second fixed layer provided on the second intermediate layer and having a fixed magnetization direction.

5. The magnetoresistive element according to claim 4, wherein the second intermediate layer is made of copper (Cu), aluminum (Al), silver (Ag) or gold (Au).

6. The magnetoresistive element according to claim 1, wherein at least one of the fixed layer and the free layer is formed by laminating a first magnetic layer, a nonmagnetic layer and a second magnetic layer in this order.

7. A magnetoresistive element comprising:

a first fixed layer having a fixed magnetization direction;

a free layer having a variable magnetization direction; and

a first intermediate layer provided between the first fixed layer and the free layer and made of a metal oxide,

wherein at least one of the first fixed layer and the free layer is formed by laminating a first magnetic layer, a nonmagnetic layer and a second magnetic layer in this order, and

the nonmagnetic layer contains a conductive metal oxide.

8. The magnetoresistive element according to claim 7, wherein the intermediate layer is made of magnesium oxide or aluminum oxide.

9. The magnetoresistive element according to claim 7, wherein the conductive metal oxide is an NaCl-type metal oxide, a spinel-type metal oxide, a perovskite-ReO₃-type metal oxide, a corundum-type metal oxide or a rutile-MoO₂-type metal oxide.

10. The magnetoresistive element according to claim 7, wherein the first magnetic layer and the second magnetic layer are antiferromagnetically or ferromagnetically exchange-coupled.

11. The magnetoresistive element according to claim 7, further comprising:

a second fixed layer having a fixed magnetization direction; and

a second intermediate layer provided between the free layer and the second fixed layer and made of a nonmagnetic material.

12. A magnetoresistive element comprising:

a laminated structure including a first fixed layer having a fixed magnetization direction, a free layer having a variable magnetization direction and a first intermediate layer provided between the first fixed layer and the free layer and made of a metal oxide; and

a protective film provided on the circumferential surface of the laminated structure and containing an insulating metal oxide.

13. The magnetoresistive element according to claim 12, wherein the first intermediate layer is made of magnesium oxide or aluminum oxide.

14. The magnetoresistive element according to claim 12, wherein the insulating metal oxide is magnesium oxide, aluminum oxide, silicon oxide or iron oxide.

15. The magnetoresistive element according to claim 12, wherein the laminated structure includes a second fixed layer having a fixed magnetization direction, and a second intermediate layer provided between the free layer and the second fixed layer and made of a nonmagnetic material.

16. A magnetoresistive element comprising:

a laminated structure including a first fixed layer having a fixed magnetization direction, a free layer having a variable magnetization direction and a first intermediate layer provided between the first fixed layer and the free layer and made of a metal oxide;

a protective film provided on a circumferential surface of the laminated structure and made of an insulator; and

a circumferential wall provided on a circumferential surface of the protective film and made of a metal oxide.

17. The magnetoresistive element according to claim 16, wherein the first intermediate layer is made of magnesium oxide or aluminum oxide.

18. The magnetoresistive element according to claim 16, wherein the metal oxide is an NaCl-type metal oxide, a spinel-type metal oxide, a perovskite-ReO₃-type metal oxide, a corundum-type metal oxide or a rutile-MoO₂-type metal oxide.

19. The magnetoresistive element according to claim 16, wherein the metal oxide is magnesium oxide, aluminum oxide, silicon oxide or iron oxide.

20. The magnetoresistive element according to claim 16, wherein the laminated structure includes a second fixed layer having a fixed magnetization direction, and a second intermediate layer provided between the free layer and the second fixed layer and made of a nonmagnetic material.