Magnetoresistive sensor having a high resistance soft magnetic layer between sensor stack and shield

• US 20040184196A1
• Filed: 03/18/2003
• Published: 09/23/2004
• Est. Priority Date: 03/18/2003
• Status: Active Grant

• Current Assignee: HGST Netherlands B.V. (Western Digital Corporation)
• Original Assignee: Hitachi Global Storage Technologies Netherlands BV (Western Digital Corporation)
• Inventors: Jayasekara, Wipul P.
• Granted Patent: US 6,995,957 B2
• Time in Patent Office: Days
• US Class Current: 360/319
• 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 5/012 Recording on, or reproducing or erasing from, magnetic disks G11B17/00, G11B19/00 take precedence
• CPC Class Codes: G11B 5/3103 Structure or manufacture of integrated heads or heads mechanically assembled and electrically connected to a support or housing
• 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 5/3146 magnetic layers
• 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 5/40 Protective measures on heads, e.g. against excessive temperature G11B5/31 takes precedence; protection against wear G11B5/255 ; protective structure of the head: see under structures, e.g. G11B5/3106

Abstract

A magnetoresistive sensor has a high resistance soft magnetic layer disposed between the sensor stack and at least one magnetic shield. The presence of the high resistance soft magnetic layer allows a smaller magnetic read gap to be achieved which results in higher recording density. The susceptibility of the magnetoresistive sensor to defects and electrostatic damage is improved. A disk drive is provided having the novel magnetoresistive sensor.

Claims

1. A magnetoresistive sensor, comprising:

a magnetoresistive sensor stack responsive to an external magnetic field;

a first and second magnetic shield wherein said magnetoresistive sensor stack is disposed between said first and second magnetic shield;

a first insulating layer disposed between said magnetoresistive sensor stack and said first magnetic shield;

a second insulating layer disposed between said magnetoresistive sensor stack and said second magnetic shield;

a high resistance soft magnetic layer disposed between at least one of said insulating layers and one of said magnetic shields.

3. A magnetoresistive sensor as in claim 1 wherein said high resistance soft magnetic layer has a composition of A-B-C where A is selected from the group consisting of Fe and Co, B is selected from the group consisting of Hf, Y, Ta, and Zr, and C is selected from the group consisting of O and N.

4. A magnetoresistive sensor as in claim 1 wherein said high resistance soft magnetic layer has a composition of CoFeHfO.

5. A magnetoresistive sensor as in claim 1 wherein said high resistance soft magnetic layer has a composition of FeHfN.

6. A magnetoresistive sensor as in claim 3 wherein said high resistivity soft magnetic layer has a magnetic moment greater than about 80 emu/cc.

7. A magnetoresistive sensor as in claim 3 wherein said high resistivity soft magnetic layer has a resistivity greater than 2000 micro-ohm-cm.

8. A magnetoresistive sensor as in claim 3 wherein said high resistivity soft magnetic layer has a permeability greater than about 200.

9. A magnetoresistive sensor as in claim 1 wherein said high resistance soft magnetic layer has a thickness of about 0.07 microns to about 2 microns.

10. A magnetoresistive sensor as in claim 1 wherein said insulating layer comprises a material selected from the group consisting of alumina, silicon oxide, silicon nitride, and tantalum oxide.

2. A magnetoresistive sensor, comprising:

a magnetoresistive sensor stack responsive to an external magnetic field;

a first and second magnetic shield wherein said magnetoresistive sensor stack is disposed between said first and second magnetic shields;

a first insulating layer disposed between said magnetoresistive sensor stack and said first magnetic shield;

a second insulating layer disposed between said magnetoresistive sensor stack and said second magnetic shield; and

,

a first high resistance soft magnetic layer disposed between said first insulating layer and said first magnetic shield and a second high resistance soft magnetic layer disposed between said second insulating layer and said second magnetic shield.

11. A disk drive, comprising:

a magnetic disk;

a write head for writing information to said disk;

a magnetoresistive sensor for reading information from said disk, wherein said magnetoresistive sensor includes;

a magnetoresistive sensor stack responsive to an external magnetic field;

a first and second magnetic shield wherein said magnetoresistive sensor stack is disposed between said first and second magnetic shield;

a first insulating layer disposed between said magnetoresistive sensor stack and said first magnetic shield;

a second insulating layer disposed between said magnetoresistive sensor stack and said second magnetic shield; and

,

a high resistance soft magnetic layer disposed between at least one of said insulating layers and one of said magnetic shields.

12. A disk drive as in claim 11 wherein said high resistance soft magnetic layer has a composition of A-B-C where A is selected from the group consisting of Fe and Co, B is selected from the group consisting of Hf, Y, Ta, and Zr, and C is selected from the group consisting of O and N.

13. A disk drive as in claim 11 wherein said high resistance soft magnetic layer has a composition of CoFeHfO.

14. A disk drive as in claim 11 wherein said high resistance soft magnetic layer has a composition of FeHfN.

15. A disk drive as in claim 11 wherein said high resistance soft magnetic layer has a magnetic moment greater than about 80 emu/cc.

16. A disk drive as in claim 11 wherein said high resistance soft magnetic layer has a resistivity greater than about 2000 micro-ohm-cm.

17. A disk drive as in claim 11 wherein permeability is greater than about 200.

18. A disk drive as in claim 11 wherein said first and second insulating layers comprise a material selected from the group consisting of alumina, silicon oxide, silicon nitride, and tantalum oxide.