Magnetoresistance effect device, magnetic head therewith, magnetic recording/reproducing head, and magnetic storing apparatus

• US 20010043448A1
• Filed: 04/19/2001
• Published: 11/22/2001
• Est. Priority Date: 08/26/1996
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Sahashi, Masashi, Iwasaki, Hitoshi, Kamiguchi, Yuzo, Saito, Kazuhiro, Fuke, Hiromi
• Granted Patent: US 6,690,553 B2
• Time in Patent Office: Days
• US Class Current: 360/324.12
• CPC Class Codes: B82Y 10/00 Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic
• CPC Class Codes: B82Y 25/00 Nanomagnetism, e.g. magnetoimpedance, anisotropic magnetoresistance, giant magnetoresistance or tunneling magnetoresistance
• CPC Class Codes: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/09 Digital recording
• 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 5/3967 Composite structural arrangements of transducers, e.g. inductive write and magnetoresistive read G11B5/3906 takes precedence
• CPC Class Codes: H01F 10/3268 the exchange coupling being asymmetric, e.g. by use of additional pinning, by using antiferromagnetic or ferromagnetic coupling interface, i.e. so-called spin-valve [SV] structure, e.g. NiFe/Cu/NiFe/FeMn
• CPC Class Codes: H10B 61/00 Magnetic memory devices, e.g. magnetoresistive RAM [MRAM] devices
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A magnetoresistance effect device comprises a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order on the front surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, at least the second ferromagnetic film having a shape corresponding to a magnetic field detecting portion. The bias magnetic field applying films are disposed on a conductive film of the magnetic multi-layer film at outer portions of both edge portions of the magnetic field detecting portion of the magnetoresistance effective film. Alternatively, the second ferromagnetic film has a first portion corresponding to the magnetic field detecting portion and a second portion corresponding to the outer portions of both the edge portions of the magnetic field detecting portion, the film thickness of the second portion being smaller than the film thickness of the first portion. The bias magnetic field applying films are formed at the outer portions of both the edge portions of the magnetic field detecting portion of the second ferromagnetic film. With the reversely structured magnetoresistance effect film and the laminate positions of the bias magnetic field applying films, in addition to suppressing the reproduction fringe and Barkhausen noise, the decrease of contact resistance, the suppression of insulation detect, and good linear response characteristic can be accomplished.

Claims

1. A magnetoresistance effect device, comprising:

a substrate having a main surface;

a magnetoresistance effect film composed of a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order above the main surface portion of the substrate, the magnetic multi-layer film having giant magnetoresistance effect, the second ferromagnetic film disposed in a magnetic field detecting portion;

a pair of bias magnetic field applying films adjacent to the both edge portions of the magnetic field detecting portion, the bias magnetic field applying films disposed on a conductive film selected from the group consisting of the antiferromagnetic film, the first ferromagnetic film, and the non-magnetic film; and

a pair of electrodes for supplying a current to the magnetoresistance effect film.

2. The magnetoresistance effect device as set forth in

claim 1

,

wherein said bias magnetic field applying film is selected from the group consisting of a hard magnetic film and a laminate film of a ferromagnetic film and an antiferromagnetic film.

3. The magnetoresistance effect device as set forth in

claim 1

,

wherein the antiferromagnetic film is composed of at least one type of metal type antiferromagnetic material selected from the group consisting of IrMn alloy, RhMn alloy, RuMn alloy, PdPtMn alloy, CrMnPt alloy, FeMn alloy, NiMn alloy, and PtMn alloy.

4. The magnetoresistance effect device as set forth in

claim 3

,

wherein a metal film having a fcc phase is formed below the antiferromagnetic film as a base film.

5. The magnetoresistance effect device as set forth in

claim 1

,

wherein at least one of the first ferromagnetic film or the second ferromagnetic film is composed of CoFe alloy.

6. The magnetoresistance effect device as set forth in

claim 1

,

wherein a magnetic film with an intermediate lattice constant of those of the antiferromagnetic film and the first ferromagnetic film is disposed therebetween.

7. The magnetoresistance effect device as set forth in

claim 1

,

wherein a magnetic film is disposed between the antiferromagnetic film and the first ferromagnetic film, and

wherein a diffusion barrier layer is disposed between the first ferromagnetic film and the magnetic film.

8. The magnetoresistance effect device as set forth in

claim 1

,

wherein a soft magnetic assist film is formed on the second ferromagnetic film.

9. The magnetoresistance effect device as set forth in

claim 1

,

wherein the distance between said electrodes is smaller than the distance between said bias magnetic field applying films.

14. The magnetoresistance effect device as set forth in

claim 1

,

wherein the antiferromagnetic film is composed of at least one metal type antiferromagnetic material selected from the group consisting of IrMn alloy, RhMn alloy, RuMn alloy, PdPtMn alloy, CrMnPt alloy, FeMn alloy, NiMn alloy, and PtMn alloy.

15. The magnetoresistance effect device as set forth in

claim 14

,

wherein a metal film having a fcc phase is formed below the antiferromagnetic film as a base film.

24. A magnetic head, comprising:

a lower magnetic shield layer;

the magnetoresistance effect device of

claim 1

,

10

, or 19, said magnetoresistance effect device being formed on said lower magnetic shield layer through a lower reproduction magnetic gap; and

an upper magnetic shield layer formed on the magnetoresistance effect device through an upper reproduction magnetic gap.

25. A magnetic recording/reproducing head, comprising:

a reproducing head having the magnetoresistance effect head of

claim 24

; and

a recording head having a lower magnetic pole in common with said lower magnetic shield layer of the magnetoresistance effect head, a record magnetic gap formed on said lower magnetic pole, and an upper magnetic pole formed on said record magnetic gap.

26. A magnetic storing apparatus, comprising:

the magnetoresistance effect device of

claim 1

,

10

, or 19;

a write electrode for storing information to a magnetoresistance effect film of the magnetoresistance effect device; and

a read electrode, composed of an electrode of the magnetoresistance effect device, for reproducing information stored in the magnetoresistance effect film.

10. A magnetoresistance effect device, comprising:

a substrate having a main surface;

a magnetoresistance effect film composed of a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order above the main surface of said substrate, the magnetic multi-layer film having giant magnetoresistance effect, the second ferromagnetic film having a first portion corresponding to a magnetic field detecting portion and a second portion corresponding to outer portions of both edge portions of the magnetic field detecting portion, the film thickness of the second portion being smaller than the film thickness of the first portion;

a pair of bias magnetic field applying films disposed on the second ferromagnetic film at the outer portions of both the edge portions of the magnetic field detecting portion; and

a pair of electrodes for supplying a current to said magnetoresistance effect films.

11. The magnetoresistance effect device as set forth in

claim 10

,

wherein said bias magnetic field applying film is selected from the group consisting of an antiferromagnetic film, a hard magnetic film, and a laminate film of a ferromagnetic film and an antiferromagnetic film.

12. The magnetoresistance effect device as set forth in

claim 10

,

wherein said bias magnetic field applying films are antimagnetic films, and

wherein the film thickness of the second ferromagnetic film at the outer portions of both the edge portions of the magnetic field detecting portion is in the range from 2 to 5 nm.

13. The magnetoresistance effect device as set forth in

claim 11

,

wherein said bias magnetic field applying films are hard magnetic films or laminate films, and

wherein the total magnetical film thickness of the hard magnetic films and the second ferromagnetic film at the outer portions of both the edge portions of the magnetic detecting portion is twice or more the magnetical film thickness of the second ferromagnetic film at the outer portions of both the edge portions of the magnetic detecting portion.

16. The magnetoresistance effect device as set forth in

claim 10

,

wherein at least one of the first ferromagnetic film or the second ferromagnetic film is composed of CoFe alloy.

17. The magnetoresistance effect device as set forth in

claim 10

,

wherein a magnetic film is disposed between the antiferromagnetic film and the first ferromagnetic film, and

wherein a diffusion barrier layer is disposed between the first ferromagnetic film and the magnetic film.

18. The magnetoresistance effect device as set forth in

claim 10

,

wherein the distance between said electrodes is smaller than the distance between said bias magnetic field applying films.

19. A magnetoresistance effect device, comprising:

a substrate having a main surface;

a magnetoresistance effect film composed of a magnetic multi-layer film having at least an antiferromagnetic film, a first ferromagnetic film, a non-magnetic film, and a second ferromagnetic film formed in the order above the main surface of said substrate, the magnetic multi-layer film having giant magnetoresistance effect, said magnetoresistance effect film having a magnetic field detecting portion;

a pair of bias magnetic field applying films formed on the second ferromagnetic film at outer portions of both edge portions of the magnetic field detecting portion of said magnetoresistance effect film; and

a pair of electrodes for supplying a current to said magnetoresistance effect film.

20. The magnetoresistance effect device as set forth in

claim 19

,

wherein the film thickness of the second ferromagnetic film is in the range from 2 to 10 nm.

21. The magnetoresistance effect device as set forth in

claim 19

,

wherein a high resistance protection film is formed on said magnetoresistance effect film and said bias magnetic field applying films.

22. The magnetoresistance effect device as set forth in

claim 19

,

wherein the distance between said electrodes is smaller than the distance between said bias magnetic field applying films.

23. The magnetoresistance effect device as set forth in

claim 19

,

wherein said bias magnetic field applying films are composed of an antiferromagnetic film.