Magnetoresistive effect element, magnetic head, and magnetic disk apparatus

• US 20070223150A1
• Filed: 10/13/2006
• Published: 09/27/2007
• Est. Priority Date: 03/27/2006
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yuasa, Hiromi, Fuji, Yoshihiko, Iwasaki, Hitoshi, Kurosaki, Yoshinari
• Granted Patent: US 8,917,485 B2
• Time in Patent Office: Days
• US Class Current: 360/324.110
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/398 Specially shaped layers
• CPC Class Codes: G11B 5/455 Arrangements for functional testing of heads; Measuring arrangements for heads
• CPC Class Codes: G11C 11/16 using elements in which the storage effect is based on magnetic spin effect
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 10/3259 Spin-exchange-coupled multilayers comprising at least a nanooxide layer [NOL], e.g. with a NOL spacer
• 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: H10N 50/10 Magnetoresistive devices

Abstract

A magnetoresistive effect element includes a magnetization fixed layer including a first crystal grain, having a magnetization direction which is fixed substantially in one direction, a spacer layer arranged on the magnetization fixed layer and having an insulating layer and a metal conductor penetrating the insulating layer, and a magnetization free layer including a second crystal grain, arranged on the spacer layer to oppose the metal conductor and having a magnetization direction which changes corresponding to an external magnetic field.

Claims

1. A magnetoresistive effect element, comprising:

a magnetization fixed layer including a first crystal grain, having a magnetization direction which is fixed substantially in one direction;

a spacer layer arranged on the magnetization fixed layer and having an insulating layer and a metal conductor penetrating the insulating layer; and

a magnetization free layer including a second crystal grain, arranged on the spacer layer to oppose the metal conductor and having a magnetization direction which changes corresponding to an external magnetic field.

2. The magnetoresistive effect element according to claim 1, wherein the metal conductor and the first crystal grain are arranged vertically to correspond with each other.

3. The magnetoresistive effect element according to claim 2, wherein at least apart of the metal conductor is formed immediately below inside the range of 30 to 70 when a diameter of the second crystal grain is expressed by a relative value from 0 to 100.

4. The magnetoresistive effect element according to claim 2, wherein the first crystal grain, the metal conductor and the second crystal grain are arranged vertically to correspond with each other.

5. The magnetoresistive effect element according to claim 1, wherein the second crystal grain is smaller than the first crystal grain.

6. The magnetoresistive effect element according to claim 1, wherein a grain diameter of the second crystal grain is 3 nanometers or larger and 10 nanometers or smaller.

7. The magnetoresistive effect element according to claim 1, wherein a grain diameter of the first crystal grain is 5 nanometers or larger and 20 nanometers or smaller.

8. The magnetoresistive effect element according to claim 7, wherein a grain diameter of the second crystal grain is 3 nanometers or larger and 10 nanometers or smaller.

9. The magnetoresistive effect element according to claim 1, further comprising

a first metal layer arranged between the magnetization free layer and the spacer layer, the first metal layer having a first component in common with the metal conductor.

10. The magnetoresistive effect element according to claim 9, wherein the first component has at least one of copper, gold, and silver.

11. The magnetoresistive effect element according to claim 10, wherein a film thickness of the first metal layer is 0.2 nanometer or larger and 1.5 nanometer or smaller.

12. The magnetoresistive effect element according to claim 1, further comprising

a second metal layer arranged between the magnetization fixed layer and the spacer layer, the second metal layer having a second component in common with the metal conductor.

13. The magnetoresistive effect element according to claim 12, wherein the second component has at least one of copper, gold, and silver.

14. The magnetoresistive effect element according to claim 12, wherein a film thickness of the second metal layer is 0.1 nanometer or larger and 1.0 nanometer or smaller.

15. The magnetoresistive effect element according to claim 12, wherein the first metal layer is thicker than the second metal layer.

16. The magnetoresistive effect element according to claim 1, wherein the magnetization fixed layer includes an iron-cobalt layer having a body-centered cubic structure or a cobalt-iron layer having a face-centered cubic structure, and the magnetization free layer includes a cobalt-iron alloy layer.

17. The magnetoresistive effect element according to claim 1, wherein at least either of the magnetization fixed layer or the magnetization free layer has a crystal structure which is at least one of face-centered cubic (111) orientation, body-centered cubic (110) orientation, hexagonal close-packed (001) orientation, and hexagonal close-packed (110) orientation perpendicular to a film face thereof and has a dispersion angle of crystal orientation being 4.0 degrees or smaller.

18. The magnetoresistive effect element according to claim 1, wherein the metal conductor has a diameter of 2 nanometers or larger and 6 nanometers or smaller.

19. The magnetoresistive effect element according to claim 1, wherein the metal conductor has a crystal structure, and the insulating layer has an amorphous structure.

20. The magnetoresistive effect element according to claim 1, wherein the insulating layer has an oxide, a nitride, or an oxynitride which includes at least one kind of element selected from the group consisting of aluminum, silicon, hafnium, titanium, tantalum, molybdenum, tungsten, niobium, magnesium, chromium, and zirconium.

21. The magnetoresistive effect element according to claim 1, further comprising

a pair of electrodes which passes a current from the magnetization fixed layer to the magnetization free layer.

22. A magnetic head comprising a magnetoresistive effect element according to claim 21.

23. A magnetic disk apparatus comprising a magnetic head according to claim 22.