Magnetoresistive effect element, and magnetic head and magnetic reproducing apparatus including the same

• US 20060077596A1
• Filed: 10/13/2005
• Published: 04/13/2006
• Est. Priority Date: 10/13/2004
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yuasa, Hiromi, Iwasaki, Hitoshi
• Granted Patent: US 7,515,387 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 5/3929 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: G11B 5/398 Specially shaped layers

Abstract

A spin-valve magnetoresistive effect film includes a magnetization fixed layer, a magnetization free layer, and a nonmagnetic intermediate layer interposed therebetween. The nonmagnetic intermediate layer has a conduction part disposed in an insulation layer and made of a nonmagnetic metal material. The ferromagnetic film stacked on an upper side of the nonmagnetic intermediate layer, out of ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer has a perpendicular orientation part which is disposed above the conduction part and whose crystal growth direction is substantially perpendicular to a film plane, and a non-perpendicular orientation part which exists in a portion other than the perpendicular orientation part. A magnetoresistive effect element has a pair of electrodes passing a sense current in a direction perpendicular to the film plane of the spin-valve magnetoresistive effect film.

Claims

1. A magnetoresistive effect element, comprising:

a magnetization fixed layer having a ferromagnetic film whose magnetization direction is fixed substantially in one direction;

a magnetization free layer having a ferromagnetic film whose magnetization direction changes according to an external magnetic field;

a nonmagnetic intermediate layer having an insulation layer and a conduction part, the insulation layer being interposed between the magnetization fixed layer and the magnetization free layer, and the conduction part being disposed in the insulation layer so as to connect the magnetization fixed layer and the magnetization free layer and made of a nonmagnetic metal material; and

a pair of electrodes arranged so as to pass a sense current in a direction substantially perpendicular to film planes of the magnetization fixed layer, the nonmagnetic intermediate layer, and the magnetization free layer,

wherein the ferromagnetic film stacked on an upper side of the nonmagnetic intermediate layer, out of the ferromagnetic films constituting the magnetization fixed layer and the magnetization free layer, has a perpendicular orientation part and a non-perpendicular orientation part, the perpendicular orientation part being disposed above the conduction part, with crystal growth direction thereof substantially perpendicular to the film plane, and the non-perpendicular orientation part existing in a portion other than the perpendicular orientation part.

2. The magnetoresistive effect element as set forth in claim 1,

wherein the nonmagnetic metal material constituting the conduction part is mainly made of at least one selected from cu (copper), gold (Au), silver (Ag), platinum (Pt), chromium (Cr), tantalum (Ta), titanium (Ti), and manganese (Mn).

3. The magnetoresistive effect element as set forth in claim 1,

wherein the conduction part has a dimension in a range from 2 to 5 nm.

4. The magnetoresistive effect element as set forth in claim 1,

wherein the conduction part realizes point contact between the magnetization fixed layer and the magnetization free layer to increase a resistance value of a portion where the magnetization fixed layer, the nonmagnetic intermediate layer, and the magnetization free layer are stacked.

5. The magnetoresistive effect element as set forth in claim 1,

wherein the insulation layer has a thickness of 5 nm or less.

6. The magnetoresistive effect element as set forth in claim 1,

wherein the conduction part has a crystalline state with crystal orientation.

7. The magnetoresistive effect element as set forth in claim 1,

wherein the conduction part has a crystalline state with a crystal growth direction being substantially perpendicular to the film plane.

8. The magnetoresistive effect element as set forth in claim 1,

wherein the non-perpendicular orientation part has an amorphous state, a low-crystalline state, or a crystalline state with an orientation direction being different from an orientation direction of the perpendicular orientation part.

9. The magnetoresistive effect element as set forth in claim 1,

wherein the non-perpendicular orientation part is disposed above the insulation layer with an amorphous state and has an amorphous state or a low-crystalline state.

10. The magnetoresistive effect element as set forth in claim 1,

wherein the magnetization free layer is disposed on an upper side of the magnetization fixed layer via the nonmagnetic intermediate layer, and the ferromagnetic film constituting the magnetization free layer has the perpendicular orientation part and the non-perpendicular orientation part.

11. The magnetoresistive effect element as set forth in claim 1,

wherein the magnetization fixed layer is stacked with an antiferromagnetic layer.

12. The magnetic head comprising the magnetoresistive effect element as set forth in claim 1.

13. A magnetic reproducing apparatus, comprising:

a magnetic recording medium; and

a magnetic head which reads information magnetically recorded on the magnetic recording medium and includes the magnetoresistive effect element as set forth in claim 1.