Magnetoresistive effect device utilizing a magnetization-coupling layer which couples adjacent ferromagnetic layers perpendicularly

• US 6,710,984 B1
• Filed: 09/25/2000
• Issued: 03/23/2004
• Est. Priority Date: 09/24/1999
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yuasa, Hiromi, Kamiguchi, Yuzo
• Primary Examiner(s): HEINZ, ALLEN J
• Application Number:
  US09/668,471
• Time in Patent Office: 1,275 Days
• Field of Search: 360/324--32
• US Class Current: 360/324.11
• 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 5/00 Recording by magnetisation or demagnetisation of a record carrier; Reproducing by magnetic means; Record carriers therefor G11B11/00 and G11B13/00 take precedence
• 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 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/3925 the two parts being thin films
• 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

Abstract

A magnetoresistance effect element has two ferromagnetic films separated by an interlayer film coupling the magnetization of one ferromagnetic layer in a direction perpendicular to the magnetization direction of the other ferromagnetic film, with an antiferromagnetic layer disposed adjacent to one of the ferromagnetic layers, and a free magnetic layer disposed adjacent to an antiferromagnetic film. The heat treatment for producing in the free layer a simple magnetic domain and the heat treatment for fixing the magnetizations of the ferromagnetic layers are simultaneously carried out. Thereby, because maintaining a difference between the blocking temperature of the antiferromagnetic layer adjacent to the free layer and the blocking temperature of an antiferromagnetic layer adjacent to the pin layer becomes unnecessary, an antiferromagnetic layer having a high exchange coupling magnetic field and a high blocking temperature can be selected. Also, because the allowable range to the dispersion of the exchange coupling magnetic field is widen, thinning of the film of the antiferromagnetic layer can be realized and the magnetoresistance effect element can be suitably applied to a magnetic reproducing head requiring a narrow gap.

Claims

1. A magnetoresistance effect element comprising:

a first ferromagnetic layer having a magnetization of a first direction,

a magnetization-coupling layer formed on the first ferromagnetic layer,

a second ferromagnetic layer formed on the magnetization-coupling layer, perpendicularly magnetic coupled with the first ferromagnetic layer by the magnetization-coupling layer, and having a magnetization of a direction substantially perpendicular to the first direction by the perpendicular magnetic coupling,

a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having a magnetization substantially parallel to the first direction at zero magnetic field.

2. The magnetoresistance effect element according to claim 1, further comprising a first antiferromagnetic layer and a second antiferromagnetic layer, the first magnetic layer disposed on the first ferromagnetic layer and exchange coupled with the first ferromagnetic layer, and the second ferromagnetic layer formed on the third ferromagnetic layer and exchange coupled with the third ferromagnetic layer.

3. The magnetoresistance effect element according to claim 1, wherein the magnetization-coupling layer has a mixed phase layer containing two kinds of oxides of a same metal each having a different valence number, or a laminated film containing two oxide layers of a same metal each having a different valence number.

4. The magnetoresistance effect element according to claim 3, wherein the oxides are selected from a group consisting of FeO, Fe₃O₄, α

—

Fe₂O₃, and γ

—

Fe₂O₃.

5. The magnetoresistance effect element according to claim 3, wherein the oxides are selected from a group consisting of CrO, Cr₂O₃, CrO₂, Cr₂O₅, CrO₃, and CrO₅.

6. The magnetoresistance effect element according to claim 3, wherein the oxides are MnO and MnO₂.

7. The magnetoresistance effect element according to claim 1, wherein the second ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field, and the third ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

8. The magnetoresistance effect element according to claim 1, wherein the third ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field, and the second ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

9. A magnetoresistance effect element, comprising:

a first ferromagnetic layer having the magnetization of a first direction,

an insertion layer formed on the first ferromagnetic layer and having a mixed phase film containing two kinds of oxides of a same metal each having a different valence number, or a laminated film having two oxide layers of a same metal each having a different valence number,

a second ferromagnetic layer formed on the insertion layer and having a magnetization of a direction substantially perpendicular to the first direction, a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having a magnetization of a direction substantially parallel to the first direction at zero magnetic field.

10. The magnetoresistance effect element according to claim 9, further comprising a first antiferromagnetic layer and a second antiferromagnetic layer, the first antiferromagnetic layer disposed on the first ferromagnetic layer and exchange coupled with the first ferromagnetic layer, and the second antiferromagnetic layer disposed on the third ferromagnetic layer and exchange coupled with the third ferromagnetic layer.

11. The magnetoresistance effect element according to claim 9, wherein the oxides are selected from a group consisting of FeO, Fe₃O₄, α

—

Fe₂O₃, and γ

—

Fe₂O₃.

12. The magnetoresistance effect element according to claim 9, wherein the oxides are selected from a group consisting of CrO, Cr₂O₃, CrO₂, Cr₂O₅, CrO₃, and CrO₅.

13. The magnetoresistance effect element according to claim 9, wherein the oxides are MnO and MnO₂.

14. The magnetoresistance effect element according to claim 9, wherein the second ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field, and the third ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

15. The magnetoresistance effect element according to claim 9, wherein the third ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field and the second ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

16. A magnetoresistance effect head, comprising:

a first ferromagnetic layer having a magnetization of a first direction,

a magnetization-coupling layer formed on the first ferromagnetic layer,

a second ferromagnetic layer formed on the magnetization-coupling layer, perpendicularly magnetic coupled with the first ferromagnetic layer by the magnetization-coupling layer, and having a magnetization of a direction substantially perpendicular to the first direction,

a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having a magnetization of a direction substantially parallel to the first direction at zero magnetic field.

17. The magnetoresistance effect head according to claim 16, further comprising a first antiferromagnetic layer and a second antiferromagnetic layer, the first antiferromagnetic layer formed on the first ferromagnetic layer and exchange coupled with the first ferromagnetic layer, and the second antiferromagnetic layer formed on the third ferromagnetic layer and exchange coupled with the third ferromagnetic layer.

18. The magnetoresistance effect head according to claim 16, wherein the magnetization coupling layer has a mixed phase film containing two kinds of oxides of a same metal each having a different valence number or a laminated film containing two oxide layers of a same metal each having a different valence number.

19. The magnetoresistance effect head according to claim 18, wherein the oxides are selected from a group consisting of FeO, Fe₃O₄, α

—

Fe₂O₃, and γ

—

Fe₂O₃.

20. The magnetoresistance effect head according to claim 18, wherein the oxides are selected from a group consisting of CrO, Cr₂O₃, CrO₂, Cr₂O₅, CrO₃, and CrO₅.

21. The magnetoresistance effect head according to claim 18, wherein the oxides are MnO and MnO₂.

22. The magnetoresistance effect head according to claim 16, wherein the second ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field and the third ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

23. The magnetoresistance effect head according to claim 16, wherein the third ferromagnetic layer is a magnetization free layer whose magnetization is free to rotate in a signal magnetic field and the second ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

24. The magnetoresistance effect head according to claim 16, wherein the magnetoresistance effect element is disposed apart from a medium facing surface, and further comprising magnetic yokes, the magnetic yokes extending from the medium facing surface to the magnetoresistance effect element and providing signal magnetic field from the medium facing surface to the magnetoresistance effect element.

25. A magnetoresistance effect head, comprising:

a first ferromagnetic layer having the magnetization of a first direction,

an insertion layer formed on the first ferromagnetic layer and having a mixed phase film containing two kinds of oxides of a same metal each having a different valence number, or a laminated film formed by laminating two oxide layers of a same metal each having a different valence number,

a second ferromagnetic layer formed on the insertion layer and having magnetization of a direction substantially perpendicular to the first direction, a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having a magnetization of a direction substantially parallel to the first direction at zero magnetic field.

26. The magnetoresistance effect head according to claim 25, wherein the oxides are selected from a group consisting of FeO, Fe₃O₄, α

—

Fe₂O₃, and γ

—

Fe₂O₃.

27. The magnetoresistance effect head according to claim 25, wherein the oxides are selected from a group consisting of CrO, Cr₂O₃, CrO₂, Cr₂O₅, CrO₃, and CrO₅.

28. The magnetoresistance effect head according to claim 25, wherein the oxides are MnO and MnO₂.

29. The magnetoresistance effect head according to claim 25, wherein the second ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field and the third ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

30. The magnetoresistance effect head according to claim 25, wherein the third ferromagnetic layer is a magnetization free layer whose magnetization is substantially free to rotate in a signal magnetic field and the second ferromagnetic layer is a magnetization fixed layer whose magnetization is substantially fixed in the signal magnetic field.

31. The magnetoresistance effect head according to claim 25, wherein the magnetoresistance effect element is disposed apart from a medium facing surface, and further comprising magnetic yokes, the magnetic yokes extending from the medium facing surface to the magnetoresistance effect element and providing a signal magnetic field from the medium facing surface to the magnetoresistance effect element.

32. A magnetic reproducing apparatus, comprising:

a magnetic recording medium and a magnetoresistance effect head reproducing a magnetic information recorded in the magnetic recording medium, the magnetoresistance effect element comprising;

a first ferromagnetic layer having a magnetization of the a first direction,

a magnetization-coupling layer formed on the first ferromagnetic layer,

a second ferromagnetic layer formed on the magnetization-coupling layer, perpendicularly magnetic coupled with the first ferromagnetic layer by the magnetization-coupling layer, and having a magnetization substantially perpendicular to the first direction, a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having a magnetization of a direction substantially parallel to the first direction at zero magnetic field.

33. A magnetic reproducing apparatus comprising:

a magnetic recording medium and a magnetoresistance effect head reproducing a magnetic information recorded in the magnetic recording medium, wherein the magnetoresistance effect element comprising;

a first ferromagnetic layer having magnetization of a first direction,

an insertion layer formed on the first ferromagnetic layer and having a mixed phase film containing two kinds of oxides of a same metal each having a different valence number or a laminated film of two oxide layers of a same metal each having a different valence number,

a second ferromagnetic layer formed on the insertion layer, and having magnetization of a direction substantially perpendicular to the first direction, a non-magnetic layer, and

a third ferromagnetic layer formed on the non-magnetic layer and having the magnetization of a direction substantially perpendicular to the first direction.

34. A magnetic laminate, comprising:

a first ferromagnetic layer having a magnetization of a first direction,

a second ferromagnetic layer having a second magnetization of a direction substantially perpendicular to the first direction, and

an insertion layer formed between the first and second ferromagnetic layers and having a mixed phase film containing two kinds of oxides of a same metal, each having a different valence number, or a laminated film containing two oxide layers of a same metal, each having a different valence number.

35. The magnetic laminate according to claim 34, wherein the oxides are selected from a group consisting of FeO, Fe₃O₄, α

—

Fe₂O₃, and γ

—

Fe₂O₃.

36. The magnetic laminate according to claim 34, wherein the oxides are selected from a group consisting of CrO, Cr₂O₃, CrO₂, Cr₂O₅, CrO₃, and CrO₅.

37. The magnetic laminate according to claim 34, wherein the oxides are MnO and MnO₂.

38. A magnetoresistance element, comprising:

a spin valve film comprising a first ferromagnetic layer having a magnetization substantially fixed in a first direction, a nonmagnetic layer formed on the first ferromagnetic layer, and a second ferromagnetic layer having a magnetization in a second direction substantially perpendicular to the first direction;

a magnetic coupling layer formed on either one of the first and second ferromagnetic layers; and

a first ferromagnetic layer formed on the magnetic coupling layer and having a magnetization in a direction substantially perpendicular to the magnetization direction of the one of the first and the second ferromagnetic layers.