IP Library Granted Patent US 8,867,178
Granted Patent B2
US 8,867,178 · App. 13/653,301 · Granted Oct 21, 2014

Read sensor with a hard bias layer having a high static field resistance

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Quick Facts
Patent No.
US 8,867,178
App. No.
13/653,301
Granted
Oct 21, 2014
Kind
B2
Abstract

In one embodiment, a magnetic sensor comprises a read element and a magnetic-domain-control film positioned on both sides of the read element in a cross-track direction. The magnetic-domain-control film has a flare shape which causes the magnetic-domain-control film to flare away in an element height direction from the depthwise end of read element and extending in both directions away from the read element in a cross-track direction. In another embodiment, a method for forming a magnetic sensor includes forming a read element and forming a magnetic-domain-control film positioned on both sides of the read element in a cross-track direction, wherein the magnetic-domain-control film has a flare shape which causes the magnetic-domain-control film to flare away from the depthwise end of read element extending in both directions in a cross-track direction.

Claims (51)

1. A magnetic sensor, comprising:

a read element; and

a magnetic-domain-control film positioned on both sides of the read element in a cross-track direction,

wherein the magnetic-domain-control film has a flare shape which causes the magnetic-domain-control film to flare away in an element height direction from a depthwise end of the read element and extending in both directions away from the read element in the cross-track direction,

wherein the flare shape comprises a starting portion of the magnetic-domain-control film positioned adjacent the read element, the starting portion having a depthwise end that is about parallel with a depthwise end of the read element,

wherein a length of the starting portion in the cross-track direction is less than about 60 nm,

wherein a depthwise length (hPM) at an end portion of the magnetic-domain-control film is about 1.2 to about 2.0 times a depthwise length (SH) of the read element, and

wherein the read element has a width in the cross-track direction at an air bearing surface (ABS) thereof that changes along a track direction that is oriented perpendicular to the cross-track direction.

2. The magnetic sensor as recited in claim 1 , wherein the flare shape causes portions of the magnetic-domain-control film positioned farther from the read element to have a greater height in the element height direction than portions of the magnetic-domain-control film positioned nearer to the read element.

3. The magnetic sensor as recited in claim 1 , wherein the read element has a shape at the ABS thereof that comprises:

a lower portion characterized by lower sides which slant toward each other along a direction from a bottom of the read element toward a top of the read element at a first angle; and

an upper portion characterized by upper sides which slant away from each other along a direction from the top of the read element toward the bottom of the read element at a second angle.

4. The magnetic sensor as recited in claim 1 , wherein the flare shape, on both sides of the read element in the cross-track direction, further comprises:

an end portion of the magnetic-domain-control film that has a depthwise end that is about parallel with the depthwise end of the read element; and

a flared end portion of the magnetic-domain-control film, extending between the starting portion and the end portion, that has a depthwise end that is angled relative to the depthwise end of the read element.

5. The magnetic sensor as recited in claim 4 , wherein a flare angle of the flare shape is in a range from about 30° to about 60°, the flare angle being measured at a flare start position where a line extending from the depthwise end of the read element intersects with the depthwise end of the flared end portion of the magnetic-domain-control film.

6. The magnetic sensor as recited in claim 4 , wherein the flare shape causes a gap length distance along the depthwise end of the starting portion of the magnetic-domain-control film, on both sides of the read element in the cross-track direction, to be no greater than about 60 nm, wherein a flare start position is positioned where a line extending from the depthwise end of the read element intersects with the depthwise end of the flared end portion of the magnetic-domain-control film.

7. The magnetic sensor as recited in claim 4 , wherein the length of the starting portion in the cross-track direction is less than about 40 nm.

8. The magnetic sensor as recited in claim 1 , wherein a flare angle of the flare shape is in a range from about 30° to about 60°, the flare angle being measured at a flare start position where a line extending from the depthwise end of the read element intersects with a depthwise end of a flared end portion of the magnetic-domain-control film.

9. The magnetic sensor as recited in claim 1 , wherein the magnetic-domain-control film comprises: Co, Fe, Pt, or an alloy comprising one or more of Co, Fe, and Pt.

10. A magnetic data storage system, comprising:

at least one magnetic head comprising a magnetic sensor as recited in claim 1 ;

a magnetic medium;

a drive mechanism for passing the magnetic medium over the at least one magnetic head; and

a controller electrically coupled to the at least one magnetic head for controlling operation of the at least one magnetic head.

11. A method for forming a magnetic sensor, the method comprising:

forming a read element having a width in a cross-track direction at an air bearing surface (ABS) thereof that changes along a track direction that is oriented perpendicular to the cross-track direction; and

forming a magnetic-domain-control film positioned on both sides of the read element in the cross-track direction,

wherein the magnetic-domain-control film has a flare shape which causes the magnetic-domain-control film to flare away in an element height direction from a depthwise end of the read element and extending in both directions away from the read element in the cross-track direction,

wherein the flare shape comprises a starting portion of the magnetic-domain-control film positioned adjacent the read element, the starting portion having a depthwise end that is about parallel with a depthwise end of the read element,

wherein a length of the starting portion in the cross-track direction is less than about 60 nm,

wherein a depthwise length (hPM) at an end portion of the magnetic-domain-control film is about 1.2 to about 2.0 times a depthwise length (SH) of the read element.

12. The method as recited in claim 11 , wherein the flare shape causes portions of the magnetic-domain-control film positioned farther from the read element to have a greater height in an element height direction than portions of the magnetic-domain-control film positioned nearer to the read element.

13. The method as recited in claim 11 , wherein the read element has a shape at the ABS thereof that comprises:

a lower portion characterized by lower sides which slant toward each other along a direction from a bottom of the read element toward a top of the read element at a first angle; and

an upper portion characterized by upper sides which slant away from each other along a direction from the top of the read element toward the bottom of the read element at a second angle.

14. The method as recited in claim 11 , wherein the flare shape, on both sides of the read element in the cross-track direction, further comprises:

an end portion of the magnetic-domain-control film that has a depthwise end that is about parallel with the depthwise end of the read element; and

a flared end portion of the magnetic-domain-control film, extending between the starting portion and the end portion, that has a depthwise end that is angled relative to the depthwise end of the read element.

15. The method as recited in claim 14 , wherein the flare shape causes a gap length distance along the depthwise end of the starting portion of the magnetic-domain-control film, on both sides of the read element in the cross-track direction, to be no greater than about 60 nm, wherein a flare start position is positioned where a line extending from the depthwise end of the read element intersects with the depthwise end of the flared end portion of the magnetic-domain-control film.

16. The method as recited in claim 14 , wherein the length of the starting portion in the cross-track direction is less than about 40 nm.

17. The method as recited in claim 11 , wherein a flare angle of the flare shape is in a range from about 30° to about 60°, the flare angle being measured at a flare start position where a line extending from the depthwise end of the read element intersects with a depthwise end of a flared end portion of the magnetic-domain-control film.

18. The method as recited in claim 11 , wherein the magnetic-domain-control film comprises: Co, Fe, Pt, or an alloy comprising one or more of Co, Fe, and Pt.

19. A magnetic sensor, comprising:

a read element having a width in a cross-track direction at an air bearing surface (ABS) thereof that changes along a track direction that is oriented perpendicular to the cross-track direction; and

a magnetic-domain-control film positioned on both sides of the read element in the cross-track direction, the magnetic-domain-control film having a flare shape which causes the magnetic-domain-control film to flare away in an element height direction from a depthwise end of the read element and extending in both directions away from the read element in the cross-track direction,

wherein the flare shape causes portions of the magnetic-domain-control film positioned farther from the read element to have a greater height in the element height direction than portions of the magnetic-domain-control film positioned nearer to the read element, and

wherein the flare shape, on both sides of the read element in the cross-track direction, is defined by three different portions:

a starting portion of the magnetic-domain-control film, positioned adjacent the read element, that has a depthwise end that is about parallel with a depthwise end of the read element, wherein a length of the starting portion in the cross-track direction is less than about 60 nm;

an end portion of the magnetic-domain-control film that has a depthwise end that is about parallel with the depthwise end of the read element; and

a flared end portion of the magnetic-domain-control film, extending between the starting portion and the end portion, that has a depthwise end that is angled relative to the depthwise end of the read element.

Assignments (5)
PATENT COLLATERAL AGREEMENT - DDTL LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 067045/0156 →
PATENT COLLATERAL AGREEMENT - A&R LOAN AGREEMENT Recorded Aug 21, 2023
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A.
Reel/Frame 064715/0001 →
RELEASE OF SECURITY INTEREST AT REEL 052915 FRAME 0566 Recorded Feb 8, 2022
From: JPMORGAN CHASE BANK, N.A.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 059127/0001 →
SECURITY INTEREST Recorded Feb 6, 2020
From: WESTERN DIGITAL TECHNOLOGIES, INC.
To: JPMORGAN CHASE BANK, N.A., AS AGENT
Reel/Frame 052915/0566 →
ASSIGNMENT OF ASSIGNOR'S INTEREST Recorded Dec 6, 2016
From: HGST NETHERLANDS B.V.
To: WESTERN DIGITAL TECHNOLOGIES, INC.
Reel/Frame 040826/0327 →