Magnetoresistance effect element, magnetic head and magnetic reproducing apparatus

• US 20020191354A1
• Filed: 03/29/2002
• Published: 12/19/2002
• Est. Priority Date: 03/30/2001
• Status: Active Grant

• Current Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Original Assignee: Kabushiki Kaisha Toshiba (Toshiba Corporation)
• Inventors: Fukuzawa, Hideaki, Yoshikawa, Masatoshi, Yuasa, Hiromi, Sahashi, Masashi, Iwasaki, Hitoshi, Koi, Katsuhiko
• Granted Patent: US 6,754,053 B2
• Time in Patent Office: Days
• 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 5/3143 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 10/324 Exchange coupling of magnetic film pairs via a very thin non-magnetic spacer, e.g. by exchange with conduction electrons of the spacer
• CPC Class Codes: H01F 10/3254 the spacer being semiconducting or insulating, e.g. for spin tunnel junction [STJ]
• CPC Class Codes: H01F 41/325 applying a noble metal capping on a spin-exchange-coupled multilayer, e.g. spin filter deposition
• CPC Class Codes: H10N 50/10 Magnetoresistive devices

Abstract

A magnetoresistance effect film including a magnetically pinned layer, a non-magnetic intermediate layer and a magnetically free layer has sidewall layers covering at least side surfaces of the magnetically pinned layer and the non-magnetic intermediate layer. The sidewall layers are made of a high-resistance oxide, nitride, fluoride, boride, sulfide or carbide having a specular reflection effect against conduction electrons, thereby to prevent non-elastic scattering of electrons and missing of spin information on side surfaces of the magnetoresistance effect film.

Claims

1. A magnetoresistance effect element comprising:

a magnetoresistance effect film having a magnetically pinned layer which includes a ferromagnetic film whose magnetization direction is pinned substantially in one direction, a magnetically free layer which includes a ferromagnetic film whose magnetization direction varies with an external magnetic field, and a non-magnetic intermediate layer interposed between the magnetically pinned layer and the magnetically free layer;

a pair of electrodes electrically connected to the magnetoresistance effect film to carry a current in a direction approximately perpendicular to the film plane of the magnetoresistance effect film; and

sidewall layers formed at least on side surfaces of the magnetically pinned layer, the non-magnetic intermediate layer and the magnetically free layer of the magnetoresistance effect film.

2. A magnetoresistance effect element according to claim 1, wherein;

the sidewall layer formed on side surfaces of the magnetically pinned layer contains as a major component thereof at least one compound selected from oxides, fluorides, nitrides, carbides, sulfides and borides containing a major element of the magnetically pinned layer,

the sidewall layer formed on side surfaces of the magnetically free layer contains as a major component thereof at least one compound selected from oxides, fluorides, nitrides, carbides, sulfides and borides containing a major element of the magnetically free layer, and

the sidewall layer formed on side surfaces of the non-magnetic intermediate layer contains as a major component thereof at least one compound selected from oxides, fluorides, nitrides, carbides, sulfides and borides containing a major component of the non-magnetic intermediate layer.

3. A magnetoresistance effect element according to claim 1, wherein the sidewall layers are substantially amorphous, and contain as a major component thereof an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind elements selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Zr, Hf, Y, Ti, Ta, Zn, Pb, Cr, Sn, Ga, Cu and rare-earth elements.

4. A magnetoresistance effect element according to claim 1, wherein,

the sidewall layers are substantially amorphous,

the sidewall layers include at least one kind of elements selected from the group consisting of Fe, Co and Ni, and at least one kind of elements selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Zr, Y, Ti, Ta, Zn, Pb, Cr, Sn, Ga, N, O, F, S, C, Cu and rare-earth elements, and

the sidewall layers are ferromagnetic.

5. A magnetoresistance effect element according to claim 1, wherein,

the sidewall layers include a crystal phase containing as a major component thereof at least one kind of elements selected from the group consisting of Fe, Co and Ni, and an amorphous phase containing as a major component thereof an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of elements selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Zr, Ti, Ta, Zn, Pb, Cr, Sn, Ga and rare-earth elements.

6. A magnetoresistance effect element according to claim 1, wherein the sidewall layers contain as a major component thereof an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of elements selected from the group consisting of B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Y, Zr, Ti, Ta, Zn, Pb, Cr, Sn, Ga and rare-earth elements, and

the sidewall layers are in form of a mixture phase mixing an amorphous phase and a crystalline phase.

7. A magnetoresistance effect element according to claim 1, wherein the sidewall layers contain as a major component thereof an oxide, fluoride, nitride, boride, carbide or sulfide of at least one kind of elements selected from the group consisting of Fe, Co, Ni, Mn, B, Al, Si, Ge, W, Nb, Mo, P, V, Sb, Hf, Zr, Ti, Ta, Zn, Pb, Cr, Sn, Ga and rare-earth elements, and

the sidewall layers are substantially crystalline.

8. A magnetoresistance effect element according to claim 1 wherein thickness of the sidewall layers is in the range from 0.5 nm to 10 nm.

9. A magnetic head including a magnetoresistance effect element according to claim 1.