Magnetoresistance effect element, magnetic head and magnetic recording and/or reproducing system

• US 20060164764A1
• Filed: 03/27/2006
• Published: 07/27/2006
• Est. Priority Date: 10/20/2000
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Yoshikawa, Masatoshi, Iwasaki, Hitoshi, Kamiguchi, Yuuzo, Koui, Katsuhiko, Yoda, Hiroaki, Takagishi, Masayuki, Nagata, Tomohiko, Yuasa, Hiromi, Sahashi, Masashi
• Granted Patent: US 7,515,386 B2
• Time in Patent Office: Days
• US Class Current: 360/324.100
• 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: 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 5/3133 including layers not usually being a part of the electromagnetic transducer structure and providing additional features, e.g. for improving heat radiation, reduction of power dissipation, adaptations for measurement or indication of gap depth or other properties of the structure G11B5/3106 takes precedence
• 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 5/39 using magneto-resistive devices or effects
• 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 5/3929 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 10/3259 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
• CPC Class Codes: Y10T 428/1114 having tunnel junction effect

Abstract

There is provided a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers to be controlled, and a magnetic head and magnetic recording and/or reproducing system using the same. In a magnetoresistance effect element wherein a sense current is caused to flow in a direction perpendicular to the plane of the film, a resistance regulating layer is provided in at least one of a pinned layer, a free layer and an non-magnetic intermediate layer. The resistance regulating layer contains, as a principal component, an oxide, a nitride, a fluoride, a carbide or a boride. The resistance regulating layer may be a continuous film or may have pin holes. Thus, it is possible to provide a practical magnetoresistance effect element which has an appropriate value of resistance, which can be sensitized and which has a small number of magnetic layers, while effectively utilizing the scattering effect depending on spin.

Claims

1-20. -20. (canceled)

21. A magnetoresistance effect element comprising:

a magnetoresistance effect film including a magnetization fixed layer having a ferromagnetic film in which the direction of magnetization is substantially fixed to one direction, a magnetization free layer having a ferromagnetic film in which the direction of magnetization varies in response to an external magnetic field, and a non-magnetic intermediate layer provided between the magnetization fixed layer and the magnetization free layer;

a pair of electrodes which are electrically connected to the magnetoresistance effect film and configured to apply a current in a direction perpendicular to the plane of the magnetoresistance effect film; and

a resistance regulating layer containing an oxide, a nitride, a fluoride, a carbide or a boride;

the resistance regulating layer formed in the non-magnetic intermediate layer or on the interface between the non-magnetic intermediate layer and at least one of the magnetization fixed layer and the magnetization free layer, and

the ferromagnetic film of at least one of the magnetization fixed layer and the magnetization free layer comprising a stacked structure which has at least a non-magnetic layer and two first magnetic layers sandwiching the non-magnetic layer, magnetizations of the first magnetic layers are substantially parallel to each other and substantially arranged in the same direction.

22. A magnetoresistance effect element as set forth in claim 21, wherein the non-magnetic layer has a film thickness of 2 nm or less.

23. A magnetoresistance effect element as set forth in claim 21, wherein the ferromagnetic film of at least one of the magnetization fixed layer and the magnetization free layer comprises at least a second magnetic layer formed of Fe or an Fe base alloy.

24. A magnetoresistance effect element as set forth in claim 21, wherein the ferromagnetic film of at least one of the magnetization fixed layer and the magnetization free layer contains at least one selected from the group consisting of FeNi, FeCo, FeSi, FeMo, and FeAl.

25. A magnetoresistance effect, element as set forth in claim 21, wherein the ferromagnetic film of at least one of the magnetization fixed layer and the magnetization free layer is formed of a Co base alloy and contains at least one selected from the group consisting of Fe, Ni, Au, Ag, Cu, Pd, Pt, Ir, Rh, Ru, Os, and Hf as an additional element.

26. A magnetoresistance effect element as set forth in claim 21, wherein the non-magnetic layer contains at least one selected from the group consisting of Cu, Ag, Au, Rh, Ru, Mn, Cr, Re, Os, and Ir.

27. A magnetoresistance effect element as set forth in claim 21, wherein the resistance regulating layer has a hole or holes provided with metal therein, two adjacent layers which contact the resistance regulating layer have an electric conduction substantially limited to conduction through the hole of the resistance regulating layer.

28. A magnetoresistance effect element comprising:

a magnetoresistance effect film including a magnetization fixed layer having a ferromagnetic film in which the direction of magnetization is substantially fixed to one direction, a magnetization free layer having a ferromagnetic film in which the direction of magnetization varies in response to an external magnetic field, and a non-magnetic intermediate layer provided between the magnetization fixed layer and the magnetization free layer;

a pair of electrodes which are electrically connected to the magnetoresistance effect film and configured to apply a current in a direction perpendicular to the plane of the magnetoresistance effect film; and

a resistance regulating layer containing an oxide, a nitride, a fluoride, a carbide or a boride;

the resistance regulating layer formed in the non-magnetic intermediate layer or on the interface between the non-magnetic intermediate layer and at least one of the magnetization fixed layer and the magnetization free layer,

the ferromagnetic film of the magnetization fixed layer comprising a stacked structure, which has at least a non-magnetic layer and two first magnetic layers sandwiching the non-magnetic layer, and a second magnetic layer formed of Fe or an Fe base alloy having a body-centered cubic structure, magnetizations of the first magnetic layers are substantially parallel to each other and substantially arranged in the same direction, and

the ferromagnetic film of the magnetization free layer comprising a third magnetic layer formed of Fe or an Fe base alloy having a body-centered cubic structure and a fourth magnetic layer having a face-centered cubic structure stacked on the third magnetic layer.

29. A magnetoresistance effect element as set forth in claim 28, wherein the resistance regulating layer has a hole or holes provided with metal therein, two adjacent layers which contact the resistance regulating layer have an electric conduction substantially limited to conduction through the hole of the resistance regulating layer.