Magnetoresistive element, magnetoresistive head and magnetic reproducing apparatus

• US 7,196,877 B2
• Filed: 12/23/2003
• Issued: 03/27/2007
• Est. Priority Date: 12/26/2002
• Status: Expired due to Fees

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yoshikawa, Masatoshi, Iwasaki, Hitoshi, Takagishi, Masayuki, Tateyama, Kohichi, Funayama, Tomomi
• Primary Examiner(s): Chen; Tianjie
• Application Number:
  US10/743,130
• Publication Number:
  US 20040190204A1
• Time in Patent Office: 1,190 Days
• Field of Search: 360/324.2, 360/314, 360/324, 360/325, 360/126, 360/324.1, 360/324.12, 296/030.8, 365/173, 438/3
• US Class Current: 360/324.1
• 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 5/313 Disposition of layers
• CPC Class Codes: G11B 5/3143 including additional layers for improving the electromagnetic transducing properties of the basic structure, e.g. for flux coupling, guiding or shielding G11B5/3116, G11B5/312 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: H01F 10/30 characterised by the composition of the intermediate layers , e.g. seed, buffer, template, diffusion preventing, cap layers H01F10/06 and H01F10/32 take precedence
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• 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: H10N 50/10 Magnetoresistive devices

Abstract

A magnetoresistive element includes a magnetoresistive film having a magnetization pinned layer, a magnetization free layer, and a nonmagnetic intermediate layer. A magnetization direction of the magnetization pinned layer is substantially fixed in an external magnetic field, a magnetization direction of the magnetization free layer is configured to change in the external magnetic field, and the nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer and has a stacked structure of a first non-metallic intermediate layer/a metal intermediate layer/a second non-metallic intermediate layer. The magnetoresistive element also includes a pair of electrodes coupled to the magnetoresistive film and is configured to provide a current in a direction substantially perpendicular to a surface of the magnetoresistive film.

Claims

1. A magnetoresistive element, comprising:

a magnetoresistive film comprising a magnetization pinned layer, a magnetization free layer, and a nonmagnetic intermediate layer, a magnetization direction of the magnetization pinned layer substantially fixed in an external magnetic field, a magnetization direction of the magnetization free layer configured to change in the external magnetic field, the nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer and having a stacked structure of a first non-metallic intermediate layer/a metal intermediate layer/a second non-metallic intermediate layer, which are stacked in a thickness direction; and

a pair of electrodes coupled to the magnetoresistive film and configured to provide a current in a direction substantially perpendicular to a surface of the magnetoresistive film.

2. The magnetoresistive element according to claim 1, wherein the metal intermediate layer has a thickness in a range of 0.5 nm to 20 nm.

3. The magnetoresistive element according to claim 1, wherein the first non-metallic intermediate layer is formed adjacent to the magnetization free layer, and the magnetoresistive element further comprising a first interface metal layer formed between the magnetization free layer and the first non-metallic intermediate layer.

4. The magnetoresistive element according to claim 1, wherein the second non-metallic intermediate layer is formed adjacent to the magnetization pinned layer, and the magnetoresistive element further comprising a second interface metal layer formed between the magnetization pinned layer and the second non-metallic intermediate layer.

5. The magnetoresistive element according to claim 4, wherein the second interface metal layer contains at least one metal selected from the group consisting of Al, Cu, Au, Ag, Pt, Pd, Ir and Os.

6. The magnetoresistive element according to claim 1, wherein the metal intermediate layer contains at least one metal selected from the group consisting of Al, Cu, Au, Ag, Pt, Pd, Ir and Os.

7. The magnetoresistive element according to claim 1, wherein each of the first and second non-metallic intermediate layers has a structure in which a columnar conductive phase is formed in an insulating phase formed of an oxide, an oxynitride or a nitride.

8. The magnetoresistive element according to claim 7, wherein the insulating phase contains an oxide, an oxynitride or a nitride of at least one element selected from the group consisting of B, Si, Ge, Ta, W, Nb, Al, Mo, P, V, As, Sb, Zr, Ti, Zn, Pb, Th, Be, Cd, Sc, La, Y, Pr, Cr, Sn, Ga, In, Rh, Pd, Mg, Li, Ba, Ca, Sr, Mn, Fe, Co, Ni, Rb and a rare earth metal, and the conductive phase contains an element selected from the group consisting of Cu, Au, Ag, Pt, Pd, Ir and Os.

9. The magnetoresistive element according to claim 7, wherein the columnar conductive phase has a size of 10 nm or less.

10. The magnetoresistive element according to claim 7, wherein an area ratio of the conductive phase in each of the surfaces of the first and second non-metallic intermediate layers is in a range of 1% to 20%.

11. The magnetoresistive element according to claim 7, wherein the conductive phases in the first and second non-metallic intermediate layers and the metal intermediate layer are formed of the same material.

12. The magnetoresistive element according to claim 7, wherein the conductive phases in the first and second non-metallic intermediate layers and the metal intermediate layer are formed of different materials.

13. The magnetoresistive element according to claim 1, further comprising an antiferromagnetic layer formed in contact with the magnetization pinned layer.

14. The magnetic reproducing apparatus according to claim 1, wherein the second non-metallic intermediate layer is formed adjacent to the magnetization pinned layer, and the magnetoresistive element further comprising a second interface metal layer formed between the magnetization pinned layer and the second non-metallic intermediate layer.

15. A magnetic reproducing head, comprising:

a magnetoresistive film comprising a magnetization pinned layer, a magnetization free layer, and a nonmagnetic intermediate layer, a magnetization direction of the magnetization pinned layer substantially fixed in an external magnetic field, a magnetization direction of the magnetization free layer configured to change in the external magnetic field, the nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer and having a stacked structure of a first non-metallic intermediate layer/a metal intermediate layer/a second non-metallic intermediate layer, which are stacked in a thickness direction; and

a pair of electrodes coupled to the magnetoresistive film and configured to provide a current in a direction substantially perpendicular to a surface of the magnetoresistive film.

16. The magnetic reproducing head according to claim 15, the magnetoresistive element further comprising a first interface metal layer formed between the magnetization free layer and the first non-metallic intermediate layer.

17. The magnetic reproducing head according to claim 15, the magnetoresistive element further comprising a second interface metal layer formed between the magnetization pinned layer and the second non-metallic intermediate layer.

19. The magnetic reproducing apparatus according to claim 17, wherein the second non-metallic intermediate layer is formed adjacent to the magnetization free layer, and the magnetoresistive element further comprising a second interface metal layer formed between the magnetization free layer and the second non-metallic intermediate layer.

18. A magnetic reproducing apparatus, comprising:

a magnetic reproducing head, the magnetic reproducing head comprising a magnetoresistive film comprising a magnetization pinned layer, a magnetization free layer, and a nonmagnetic intermediate layer, a magnetization direction of the magnetization pinned layer substantially fixed in an external magnetic field, a magnetization direction of the magnetization free layer configured to change in the external magnetic field, the nonmagnetic intermediate layer formed between the magnetization pinned layer and the magnetization free layer and having a stacked structure of a first non-metallic intermediate layer/a metal intermediate layer/a second non-metallic intermediate layer, which are stacked in a thickness direction; and

a pair of electrodes coupled to the magnetoresistive film and configured to provide a current in a direction substantially perpendicular to a surface of the magnetoresistive film.