Magnetic recording head with a side shield structure for controlling side reading of thin film read sensor

• US 6,943,993 B2
• Filed: 02/11/2003
• Issued: 09/13/2005
• Est. Priority Date: 02/11/2003
• Status: Expired due to Term

• Current Assignee: JP Morgan Chase Bank, N.A. (JP Morgan Chase & Co)
• Original Assignee: Western Digital (Fremont) Incorporated (Western Digital Corporation)
• Inventors: Chang, Thomas Young, Gong, Heng, Zhang, Jing, Chen, Yingjian
• Primary Examiner(s): EVANS, JEFFERSON A
• Application Number:
  US10/364,799
• Publication Number:
  US 20040156148A1
• Time in Patent Office: 945 Days
• Field of Search: 360/317, 360/319, 360/126, 360/324.1, 360/324.11, 360/324.12, 360/324.2
• 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: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• 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 5/313 Disposition of layers
• 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 5/3146 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 5/3909 Arrangements using a magnetic tunnel junction
• 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 5/3935 Flux closure films not being part of the track flux guides
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers

Abstract

Side shield structures magnetically shielding a read sensor to block side reading of tracks on a magnetic media. The read heads include bottom and top magnetic shield layers, a read sensor or magnetically sensitive element between the bottom and top magnetic shield layers, and a side shield assembly formed of magnetically shielding material positioned between the bottom and top magnetic shield layers and adjacent at least a portion of the read sensor. In current-in-plane embodiments, the side shield assembly includes a pair of side shields of magnetically shielding material adjacent a lower portion of the read sensor formed on a lower read gap. In current-perpendicular-to-plane embodiments, the side shield assembly includes a pair of side shields extending from the bottom magnetic shield adjacent lower sides of the read sensor and/or a pair of side shields extending from the top magnetic shield adjacent upper sides of the read sensor.

Claims

1. A read head for reading data from a magnetic media having a plurality of adjacent circular tracks, comprising:

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor including electrically conducting material disposed between the bottom and top magnetic shield layers configured for sensing changes in magnetic properties of a track on the magnetic media positioned under the read sensor;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent to the read sensor, the side shield assembly adapted to magnetically shield the read sensor from reading magnetic signals of a track adjacent to the track under the read sensor, wherein the side shield assembly includes a first side shield element that is positioned adjacent to a first side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a shielding distance and wherein the side shield assembly further includes a second side shield element that is positioned adjacent to a second side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a distance about equal to the shielding distance;

a bottom electrical contact layer deposited over the first and second side shield elements and the bottom magnetic shield layer;

a pair of read gap elements positioned on the bottom electrical contact layer adjacent to the first and second sides of the read sensor, and

a top electrical contact layer positioned over the read gap elements and the read sensor.

2. The read head of claim 1, further including a pair of bias elements comprising hard magnetic material deposed adjacent the first and second sides of the read sensor between the read gap elements and the bottom electrical contact layer.

3. The read head of claim 1, wherein the side shield assembly further includes a third side shield element extending a top shielding distance from the top magnetic shield layer adjacent the first side of the read sensor and a fourth side shield element extending the top shielding distance from the top magnetic shield layer adjacent the second side of the read sensor.

4. The read head of claim 3, wherein the read gap elements abut the first and second sides of the read sensor such that the top electrical contact layer and the adjacent third and fourth side shield elements extend the top shielding distance proximal to the first and second sides of the read sensor spaced apart by the read gap elements.

5. A method of fabricating a thin film read head having improved shielding against side reading, comprising:

providing a substrate;

depositing a film of magnetic insulation material over the substrate to form a bottom magnetic shield layer;

forming first and second side shield elements on the bottom magnetic shield layer, the first and second side shield elements being spaced apart for insertion of additional materials on the bottom magnetic shield layer and comprising a magnetic insulation material;

depositing a film of electrically conductive material over the first and second side shield elements and the bottom magnetic shield layer at the space defined between the first and second side shield elements;

forming a magnetically sensitive element on the deposited electrically conductive film between the first and second side shield elements;

forming a pair of read gap elements adjacent sides of the magnetically sensitive element;

depositing an additional film of electrically conductive material over the read gap elements and the magnetically sensitive element; and

forming a top magnetic shield layer of magnetic insulation material on the additional film of electrically conductive material.

6. The method of claim 5, wherein the forming of the first and second side shield elements includes removing a portion of the magnetic insulation material of the bottom magnetic shield layer.

7. The method of claim 6, wherein the magnetic insulation material of the bottom magnetic shield layer is a soft magnetic alloy.

8. The method of claim 5, wherein the forming of the top magnetic shield layer includes forming third and fourth side shield elements of extending toward the first and second side shield elements along the sides of the magnetically sensitive element.

9. The method of claim 8, wherein the forming of the read gap elements includes patterning recesses to define the third and fourth side shield elements.

10. The method of claim 5, further including forming a pair of bias elements adjacent the sides of the magnetically sensitive element between the film of electrically conductive material and the read gap elements, the bias elements comprising a hard magnetic material.

11. A method of fabricating a thin film read head having improved shielding against side reading, comprising:

providing a substrate;

depositing a film of magnetic insulation material over the substrate to form a bottom magnetic shield layer;

forming a magnetically sensitive element on the bottom magnetic shield layer having first and second sides;

forming first and second side shield elements comprising a magnetic insulation material adjacent the first and second sides of the magnetically sensitive element;

forming a top magnetic shield layer of magnetic insulation material over the magnetically sensitive element the first and second side shield elements;

deposition a first layer of read gap material on the bottom magnetic shield layer prior to the forming of the magnetically sensitive element;

forming a pair of bias elements on the first and second side shield elements of hard magnetic material adjacent the first and second sides of the magnetically sensitive element;

forming a pair of electrical leads over the bias elements contacting the first and second sides of the magnetically sensitive element; and

depositing a second layer of read gap material over the electrical leads and the magnetically sensitive element.

12. A system for storing and retrieving digital data to and from a magnetic recording media, comprising:

a head assembly positionable adjacent the magnetic recording media comprising;

a write head; and

a read head comprising;

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor including electrically conducting material disposed between the bottom and top magnetic shield layers configured for sensing changes in magnetic properties of a track on the magnetic media positioned under the read sensor;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent to the read sensor, the side shield assembly adapted to magnetically shield the read sensor from reading magnetic signals of a track adjacent to the track under the read sensor, wherein the side shield assembly comprises a first layer of magnetically shielding material deposited on the bottom read gap layer adjacent to the first side of the read sensor and a second layer of magnetically shielding material deposited on the bottom read gap layer adjacent to the second side of the read sensor;

a pair of electrical contacts positioned between the bottom and top magnet shield layers contacting first and second sides of the read sensor;

a bottom read gap layer disposed between the bottom magnetic shield layer and the read sensor and the side shield assembly;

a top read gap layer disposed between the top magnetic shield layer and the read sensor and the pair of electrical contacts; and

a pair of hard magnetic elements positioned adjacent to the first and second sides of the read sensor between the first and second layers of magnetically shielding material and the electrical contacts; and

a drive device for coupling to the media so as to move the media with respect to the head assembly.

13. The system of claim 12, wherein the magnetically shielding material is selected from the group of alloys consisting of a NiFe alloy, a CoZrNb alloy, and a CoNiFe alloy.

14. A read head for reading data from a magnetic media having a plurality of adjacent circular tracks, comprising:

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor including electrically conducting material disposed between the bottom and top magnetic shield layers that is configured for sensing changes in magnetic properties of a track on the magnetic media that is positioned under the read sensor;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent to the read sensor, the side shield assembly being adapted to magnetically shield the read sensor from reading magnetic signals of a track that is adjacent to the track under the read sensor;

a pair of electrical contacts positioned between the bottom and top magnet shield layers and contacting first and second sides of the read sensor;

a bottom read gap layer disposed between the bottom magnetic shield layer and the read sensor and the side shield assembly;

a top read gap layer disposed between the top magnetic shield layer and the read sensor and the pair of electrical contacts, wherein the side shield assembly comprises a first layer of magnetically shielding material deposited on the bottom read gap layer adjacent to the first side of the read sensor and a second layer of magnetically shielding material deposited on the bottom read gap layer adjacent to the second side of the read sensor; and

a pair of hard magnetic elements positioned adjacent to the first and second sides of the read sensor between the first and second layers of magnetically shielding material and the electrical contacts.

15. The read head of claim 14, wherein the magnetically shielding material is selected from the group of alloys consisting of a NiFe alloy, a CoZrNb alloy, and a CoNiFe alloy.

16. A system for storing and retrieving digital data to and from a magnetic recording media, comprising:

a head assembly positionable adjacent the magnetic recording media comprising;

a write head; and

a read head comprising;

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor including electrically conducting material disposed between the bottom and top magnetic shield layers configured for sensing changes in magnetic properties of a track on the magnetic media positioned under the read sensor;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent the read sensor, the side shield assembly adapted to magnetically shield the read sensor from reading magnetic signals of a track adjacent the track under the read sensor, wherein the side shield assembly includes a first side shield element that is positioned adjacent to a first side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a shielding distance and wherein the side shield assembly further includes a second side shield element that is positioned adjacent to a second side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a distance about equal to the shielding distance; and

a bottom electrical contact layer deposited over the first and second side shield elements and the bottom magnetic shield layer;

a pair of read gap elements positioned on the bottom electrical contact layer adjacent the first and second sides of the read sensor; and

a top electrical contact layer positioned over the read gap elements and the read sensor; and

a drive device for coupling to the media so as to move the media with respect to the head assembly.

17. The system of claim 16, the read head further including a pair of bias elements comprising hard magnetic material deposed adjacent to the first and second sides of the read sensor between the read gap elements and the bottom electrical contact layer.

18. The system of claim 16, wherein the side shield assembly further includes a third side shield element extending a top shielding distance away from the top magnetic shield layer adjacent to the first side of the read sensor and a fourth side shield element extending away from the top magnetic shield layer for the top shielding distance adjacent to the second side of the read sensor.

19. The system of claim 18, wherein the read gap elements abut the first and second sides of the read sensor such that the top electrical contact layer and the adjacent third and fourth side shield elements are proximal to the first and second sides of the read sensor and are spaced apart from the first and second sides of the read sensor by the read gap elements.

20. A read head for reading data from a magnetic media having a plurality of adjacent circular tracks, comprising:

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor disposed between the bottom and top magnetic shield layers;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent to the read sensor, the side shield assembly adapted to magnetically shield the read sensor from reading magnetic signals of a track that is adjacent to the track under the read sensor;

a bottom electrical contact layer deposited over the first and second side shield elements and the bottom magnetic shield layer;

a pair of read gap elements positioned on the bottom electrical contact layer adjacent to the first and second sides of the read sensor, and

a top electrical contact layer positioned over the read gap elements and the read sensor;

wherein the side shield assembly further includes a first top side shield element positioned adjacent to the first side of the read sensor and extending away from the top magnetic shield layer toward the bottom magnetic shield layer for a shielding distance and further including a second top side shield element positioned adjacent to the second side of the read sensor and extending away from the top magnetic shield layer toward the bottom magnetic shield layer for a distance equal to about the shielding distance; and

wherein the read gap elements abut the first and second sides of the read sensor such that the top electrical contact layer and the first and second top side shield elements are proximal to the first and second sides of the read sensor but are spaced apart from the read sensor by the read gap elements.

21. A read head for reading data from a magnetic media having a plurality of adjacent circular tracks, comprising:

a bottom magnetic shield layer;

a top magnetic shield layer;

a read sensor disposed between the bottom and top magnetic shield layers;

a side shield assembly positioned between the bottom and top magnetic shield layers and adjacent the read sensor, wherein the side shield assembly includes a first side shield element that is positioned adjacent to a first side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a shielding distance and wherein the side shield assembly further includes a second side shield element that is positioned adjacent to a second side of the read sensor and that extends away from the bottom magnetic shield layer toward the top magnetic shield layer for a distance about equal to the shielding distance, the first and second side shield elements being formed integrally with the bottom magnetic shield layer and comprising a magnetically insulating material; and

a bottom electrical contact layer deposited over the first and second side shield elements and the bottom magnetic shield layer.