Magnetic sensing element with ESD resistance improved by adjusting the lengths of antiferromagnetic layers and free layer in the height direction

• US 6,867,952 B2
• Filed: 01/16/2003
• Issued: 03/15/2005
• Est. Priority Date: 01/22/2002
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Hasegawa, Naoya
• Primary Examiner(s): HEINZ, ALLEN J
• Application Number:
  US10/345,881
• Publication Number:
  US 20030179519A1
• Time in Patent Office: 789 Days
• Field of Search: 360/324.12
• 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 2005/0016 of magnetoresistive transducers
• 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
• CPC Class Codes: G11B 5/3932 Magnetic biasing films
• CPC Class Codes: Y10T 29/49034 Treating to affect magnetic properties

Abstract

A magnetic sensing element having a reduced electrical resistance and a large exchange anisotropic magnetic field between a free layer and antiferromagnetic layers for exchange biasing is provided. The magnetic sensing element includes second antiferromagnetic layers and a free magnetic layer, and the length of the second antiferromagnetic layers in a height direction in side regions disposed at the lateral sides of a track width region is larger than the length of the free magnetic layer in the height direction in the track width region.

Claims

1. A magnetic sensing element comprising:

a laminate comprising;

a first antiferromagnetic layer;

a pinned magnetic layer on the first antiferromagnetic layer;

a nonmagnetic material layer on the pinned magnetic layer; and

a free magnetic layer on the nonmagnetic material layer; and

a pair of second antiferromagnetic layers on the free magnetic layer, the second antiferromagnetic layers being separated from each other in a track width direction by a gap therebetween,

wherein a length of the second antiferromagnetic layers in a height direction is larger than a length of the free magnetic layer in the height direction in a track width region.

2. The magnetic sensing element according to claim 1,

wherein at least part of an inner end face of each of the second antiferromagnetic layers is a vertical face, a curved face, or a slope that extends in the height direction, in which the vertical faces, the curved faces, or the slopes of the second antiferromagnetic layers are separated from each other with a gap corresponding to a track width therebetween, and

wherein a length of the vertical faces, the curved faces, or the slopes in the height direction is larger than the length of the free magnetic layer in the height direction in the track width region.

3. The magnetic sensing element according to claim 2, wherein the vertical faces, the curved faces, or the slopes of the second antiferromagnetic layers have a length in the height direction of 1 μ

m or more.

4. The magnetic sensing element according to claim 2, wherein the vertical faces, the curved faces, or the slopes of the second antiferromagnetic layers have a length in the height direction of 10 μ

m or less.

5. The magnetic sensing element according to claim 1, wherein the length of the free magnetic layer in the height direction at side regions at lateral sides of the track width region is larger than the length at the free magnetic layer in the height direction in the track width region.

6. The magnetic sensing element according to claim 5, wherein at least part of an inner end face of the free magnetic layer at the side regions is a vertical face, a curved face, or a slope that extends in the height direction,

wherein a length of the vertical face, the curved face, or the slope of the free magnetic layer in the height direction is larger than the length of the free magnetic layer in the height direction in the track width region.

7. The magnetic sensing element according to claim 6, wherein the vertical face, the curved face, or the slope of the free magnetic layer has a length in the height direction of 1 μ

m or more.

8. The magnetic sensing element according to claim 6, wherein the vertical, the curved face, or the slope of the free magnetic layer has a length in the height direction of 10 μ

m or less.

9. The magnetic sensing element according to claim 1, wherein the second antiferromagnetic layers completely cover portions of the free magnetic layer at side regions.

10. The magnetic sensing element according to claim 1, further comprising electrode layers on the second antiferromagnetic layers, the electrode layers comprising a conductive material having a resistivity lower than that an antiferromagnetic material of the second antiferromagnetic layers.

11. The magnetic sensing element according to claim 10, wherein the electrode layers completely cover top faces of the second antiferromagnetic layers.

12. The magnetic sensing element according to claim 1, wherein a thickness of the second antiferromagnetic layers or a thickness electrode layers at side regions is smaller in region behind a rear end face of the free magnetic layer in the height direction than in regions from a face of the magnetic sensing element opposing a recording medium up to the rear end face of the free magnetic layer.