Antiparallel-pinned type spin valve sensor having ultra-thin freelayers

• US 20030189800A1
• Filed: 04/03/2002
• Published: 10/09/2003
• Est. Priority Date: 04/03/2002
• Status: Active Grant

• Current Assignee: International Business Machines Corporation
• Original Assignee: International Business Machines Corporation
• Inventors: Pinarbasi, Mustafa
• Granted Patent: US 6,826,021 B2
• Time in Patent Office: Days
• US Class Current: 360/324.12
• 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 5/3116 Shaping of layers, poles or gaps for improving the form of the electrical signal transduced, e.g. for shielding, contour effect, equalizing, side flux fringing, cross talk reduction between heads or between heads and information tracks G11B5/3113, G11B5/245 take precedence
• CPC Class Codes: G11B 5/3903 using magnetic thin film layers or their effects, the films being part of integrated structures

Abstract

An antiparallel (AP) pinned type spin valve (SV) sensor having ultra-thin freelayers includes a cap layer made of tantalum (Ta); a copper (Cu) layer formed beneath the cap layer; a freelayer structure which includes a first layer made of nickel-iron (NiFe), a second layer made of ruthenium (Ru), a third layer made of nickel-iron (NiFe), and a nanolayer made of cobalt-iron (CoFe); and a spacer layer made of copper (Cu). This structure provides a method to optimize the net freelayer moment by an optimal combination of CoFe and NiFe for a high magnetoresistive coefficient (dR/R) and soft magnetic properties.

Claims

1. A spin valve (SV) sensor, comprising:

a cap layer made of tantalum (Ta);

a copper (Cu) layer formed beneath the cap layer;

a freelayer structure which includes;

a first layer made of nickel-iron (NiFe);

a second layer made of ruthenium (Ru);

a third layer made of nickel-iron (NiFe);

a nanolayer made of cobalt-iron (CoFe); and

a spacer layer made of copper (Cu).

2. The SV sensor of claim 1, wherein a net freelayer thickness of the SV is less than 50 Angstroms.

3. The SV sensor of claim 1, wherein the nanolayer has a thickness that is no more than 30 Angstroms.

4. The SV sensor of claim 1, wherein a net freelayer thickness of the SV is less than 50 Angstroms and the nanolayer has a thickness that is no more than 30 Angstroms.

5. The SV sensor of claim 1, wherein the SV sensor comprises an antiparauel-pinned (AP) type sensor.

6. The SV sensor of claim 1, further comprising:

a first antiparallel (AP) pinned layer;

a second AP-pinned layer; and

an antiparallel coupling (APC) layer disposed between the first and the second AP-pinned layers.

7. A magnetic head, comprising:

a spin valve (SV) sensor which includes;

a cap layer made of tantalum (Ta);

a copper (Cu) layer formed beneath the cap layer;

a freelayer structure which includes a first layer made of nickel-iron (NiFe), a second layer made of ruthenium (Ru), a third layer made of nickel-iron (NiFe), and a nanolayer made of cobalt-iron (CoFe); and

a spacer layer made of copper (Cu).

8. The magnetic head of claim 7, wherein a net freelayer thickness of the SV sensor is less than 50 Angstroms.

9. The magnetic head of claim 7, wherein the nanolayer has a thickness that is no more than 30 Angstroms.

10. The magnetic head of claim 7, wherein a net freelayer thickness of the SV sensor is less than 50 Angstroms and the nanolayer has a thickness that is no more than 30 Angstroms.

11. The magnetic head of claim 7, wherein the SV sensor comprises an antiparallel (AP) pinned type sensor.

12. The magnetic head of claim 7, further comprising:

a first antiparallel (AP)-pinned layer;

a second AP-pinned layer; and

an antiparallel coupling (APC) layer disposed between the first and the second AP-pinned layers.

13. A disk drive, comprising:

a magnetic head with a spin valve (SV) sensor which includes;

a cap layer made of tantalum (Ta);

a copper (Cu) layer formed beneath the cap layer;

a freelayer structure which includes a first layer made of nickel-iron (NiFe), a second layer made of ruthenium (Ru), a third layer made of nickel-iron (NiFe), and a nanolayer made of cobalt-iron (CoFe); and

a spacer layer made of copper (Cu).

14. The disk drive of claim 13, wherein a net freelayer thickness of the SV sensor is less than 50 Angstroms.

15. The disk drive of claim 13, wherein the nanolayer has a thickness that is no more than 30 Angstroms.

16. The disk drive of claim 13, wherein a net freelayer thickness of the SV sensor is less than 50 Angstroms and the nanolayer has a thickness that is no more than 30 Angstroms.

17. The disk drive of claim 13, wherein the SV sensor comprises an antiparallel (AP) pinned type sensor.

18. The disk drive of claim 13, further comprising:

a first antiparallel (AP)-pinned layer;

a second AP-pinned layer; and

an antiparallel coupling (APC) layer disposed between the first and the second AP-pinned layers.