Magnetoresistive effect element, magnetic head and magnetic reproducing apparatus

• US 7,218,483 B2
• Filed: 06/21/2002
• Issued: 05/15/2007
• Est. Priority Date: 06/22/2001
• Status: Expired due to Term

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yoshikawa, Masatoshi, Yuasa, Hiromi, Sahashi, Masashi, Koui, Katsuhiko, Iwasaki, Hitoshi
• Primary Examiner(s): Chen; Tianjie
• Application Number:
  US10/175,960
• Publication Number:
  US 20030011945A1
• Time in Patent Office: 1,789 Days
• Field of Search: 360/324.1, 360/324.2, 360/314, 365/97, 257/77, 257/432, 369/240, 362/303, 296/031.3, 296/031.4, 313/310, 372/45.01
• 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: B82Y 40/00 Manufacture or treatment of nanostructures
• CPC Class Codes: G01R 33/093 using multilayer structures, e.g. giant magnetoresistance sensors thin magnetic films H01F10/00
• 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 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects
• CPC Class Codes: G11B 5/3909 Arrangements using a magnetic tunnel junction
• CPC Class Codes: G11B 5/3929 Disposition of magnetic thin films not used for directly coupling magnetic flux from the track to the MR film or for shielding
• CPC Class Codes: H01F 10/1936 Half-metallic, e.g. epitaxial CrO2 or NiMnSb films
• 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: H01F 10/3281 only by use of asymmetry of the magnetic film pair itself, i.e. so-called pseudospin valve [PSV] structure, e.g. NiFe/Cu/Co
• CPC Class Codes: H01F 41/305 applying the spacer or adjusting its interface, e.g. in order to enable particular effect different from exchange coupling
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A spin valve type magnetoresistive effect element for vertical electric conduction includes a magnetoresistive effect film in which a resistance adjustment layer made of a material containing conductive carriers not more than 10²²/cm³ is inserted. Thus the resistance value of a portion in change of spin-relied conduction is raised to an adequate value, thereby to increase the resistance variable amount.

Claims

1. A magnetoresistive effect element comprising:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose direction of magnetization varies in response to an external magnetic field, a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer, and a resistance adjustment layer interposed between said magnetization-pinned layer and said magnetization free layer and containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^x)Si, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi; and

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect film,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.

2. A magnetoresistive effect element according to claim 1, wherein said resistance adjustment layer is interposed at least in one of a location between said magnetization-pinned layer and said nonmagnetic metallic intermediate layer and a location between said magnetization free layer and said nonmagnetic metallic intermediate layer.

3. A magnetoresistive effect element according to claim 1, wherein said resistance adjustment layer is interposed in said nonmagnetic metallic intermediate layer.

4. A magnetoresistive effect element according to claim 1, wherein a thickness of said resistance adjustment layer is equal to or less than 1 nm.

5. A magnetoresistive effect element according to claim 1, further comprising an insulating layer located adjacent to said resistance adjustment layer and made of an oxide.

6. A magnetoresistive effect element according to claim 5, wherein said insulating layer is located nearer to a supply side of electrons forming said sense current with respect to said resistance adjustment layer.

7. A magnetoresistive effect element according to claim 1, wherein said resistance adjustment layer contains a quantity of conductive carriers not more than 10²²/cm³.

8. A magnetoresistive effect element comprising:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose direction of magnetization varies in response to an external magnetic field, and a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer;

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect film, wherein said nonmagnetic intermediate layer is a resistance adjustment layer containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^xSi, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.

9. A magnetoresistive effect element according to claim 8, wherein a thickness of said resistance adjustment layer is equal to or less than 3 nm.

10. A magnetoresistive effect element according to claim 8, further comprising an insulating layer located adjacent to said resistance adjustment layer and made of an oxide.

11. A magnetoresistive effect element according to claim 10, wherein said insulating layer is located nearer to a supply side of electrons forming said sense current with respect to said resistance adjustment layer.

12. A magnetoresistive effect element according to claim 8, wherein said resistance adjustment layer contains a quantity of conductive carriers not more than 10²²/cm³.

13. A magnetic head comprising a magnetoresistive effect element having:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose direction of magnetization varies in response to an external magnetic field, a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer, and a resistance adjustment layer interposed between said magnetization-pinned layer and said magnetization free layer and containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^x)Si, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi; and

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect films,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.

14. A magnetic head comprising a magnetoresistive effect element having:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose—

direction of magnetization varies in response to an external magnetic field, and a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer;

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect film,

wherein said nonmagnetic intermediate layer is a resistance adjustment layer containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^x)Si, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.

15. A magnetic reproducing apparatus which reads information magnetically recorded in a magnetic recording medium, said magnetic reproducing apparatus comprising a magnetoresistive effect element having:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose direction of magnetization varies in response to an external magnetic field, a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer, and a resistance adjustment layer interposed between said magnetization-pinned layer and said magnetization free layer and containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^x)Si, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi; and

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect film,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.

16. A magnetic reproducing apparatus which reads information magnetically recorded in a magnetic recording medium, said magnetic reproducing apparatus comprising a magnetoresistive effect element having:

a magnetoresistive effect film including a magnetization-pinned layer having a magnetic film whose direction of magnetization is pinned substantially in one direction, a magnetization free layer having a magnetic film whose direction of magnetization varies in response to an external magnetic field, and a nonmagnetic metallic intermediate layer interposed between said magnetization-pinned layer and said magnetization free layer;

a pair of electrodes electrically coupled to said magnetoresistive effect film to supply a sense current substantially vertically of the film plane of said magnetoresistive effect film,

wherein said nonmagnetic intermediate layer is a resistance adjustment layer containing, as a major component, one material selected from the group consisting of CoSi, (Co^1-xFe^x)Si, (Co^1-xNi^x)Si, (Co^1-xMn^x)Si, (Co^1-xCr^x)Si and FeSi,

wherein the magnetization-pinned layer includes first and second ferromagnetic layers, and an anti-parallel coupling layer disposed between the first and second ferromagnetic layers, the anti-parallel coupling layer coupling the first and second ferromagnetic layers in an anti-parallel magnetization direction.