GMR magnetic sensing element having an antiferromagnetic layer extending beyond the track width and method for making the same

• US 7,050,276 B2
• Filed: 06/13/2003
• Issued: 05/23/2006
• Est. Priority Date: 06/13/2002
• Status: Expired due to Fees

• Current Assignee: TDK Corporation
• Original Assignee: ALPS Electric Company Limited (Alps Alpine Co., Ltd.)
• Inventors: Nishiyama, Yoshihiro
• Primary Examiner(s): CASTRO, ANGEL A
• Application Number:
  US10/461,809
• Publication Number:
  US 20030231436A1
• Time in Patent Office: 1,075 Days
• Field of Search: 360/324.11, 360/324.12, 360/324.1, 360/324.2
• US Class Current: 360/324.11
• 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
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers

Abstract

A magnetic sensing element with improved magnetic detection output and a method for making the same are provided. In the magnetic sensing element, the length of an upper pinned magnetic layer an upper antiferromagnetic layer in a track width direction is larger than the length of a free magnetic layer in the track width direction. In making the magnetic sensing element, there is no need to remove side portions of the upper pinned magnetic layer and the upper antiferromagnetic layer. The materials of the upper pinned magnetic layer and the upper antiferromagnetic layer are thus prevented from redepositing on two side faces of the free magnetic layer during milling.

Claims

1. A magnetic sensing element comprising a composite film comprising, in order from the bottom:

a free magnetic layer;

a first nonmagnetic material layer;

a first pinned magnetic layer; and

a first antiferromagnetic layer,

wherein an electric current flows in the composite film in a direction perpendicular to a surface of each layer of the composite film,

wherein a length of the antiferromagnetic layer in a track width direction is larger than a length of the free magnetic layer in the track width direction,

wherein the composite film further comprising a current limiting layer disposed between the first nonmagnetic material layer and the first pinned magnetic layer,

wherein the current limiting layer comprises an insulating component and a conductive component, and

wherein a length of the current limiting layer in the track width direction is equal to a length of the first nonmagnetic material layer in the track width direction.

2. The magnetic sensing element according to claim 1, the composite film further comprising:

a second nonmagnetic material layer;

a second pinned magnetic material layer; and

a second antiferromagnetic material layer, which are disposed under the free magnetic layer,

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

3. The magnetic sensing element according to claim 2, wherein, side faces of the first nonmagnetic layer, the free magnetic layer and the second nonmagnetic layer are aligned with each other and form sloped side faces on the track width direction.

4. The magnetic sensing element according to claim 1, wherein, side faces of the first nonmagnetic layer and the free magnetic layer are aligned with each other and form sloped side faces on the track width direction.

5. The magnetic sensing element according to claim 1, wherein, the first pinned magnetic layer comprises of a first magnetic sublayer, a second magnetic sublayer and an intermediate sublayer disposed between the magnetic sublayers.

6. The magnetic sensing element according to claim 1, wherein, the first nonmagnetic layer comprises of a lower nonmagnetic sublayer and upper nonmagnetic sublayer,

side faces of the lower nonmagnetic sublayer of the first nonmagnetic layer and the free magnetic are aligned with each other and form sloped side faces on the track width direction, and

wherein a length of the current limiting layer in the track width direction is about equal to a length of the lower nonmagnetic sublayer of the first nonmagnetic layer in the track width direction.

7. A magnetic sensing element comprising a composite film comprising, in order from the top:

a first antiferromagnetic layer,

a first pinned magnetic layer,

a first nonmagnetic layer;

a free magnetic layer;

a second nonmagnetic layer;

a second pinned magnetic layer; and

a second antiferromagnetic layer,

wherein an electric current flows in the composite film in a direction perpendicular to a surface of each layer of the composite film,

wherein each length of the first and second antiferromagnetic layers in a track width direction is larger than a length of the free magnetic layer in the track width direction, and

wherein a length of the second pinned magnetic layer in the track width direction is larger than the length of the free magnetic layer in the track width direction.

8. The magnetic sensing element according to claim 7, wherein a length of the first pinned magnetic layer in the track width direction is larger than the length of the free magnetic layer in the track width direction.

9. The magnetic sensing element according to claim 7, the composite film further comprising a current limiting layer disposed between the first nonmagnetic layer and the first pinned magnetic layer,

wherein the current limiting layer comprises an insulating component and a conductive component, and

wherein a length of the current limiting layer in the track width direction is about equal to a length of the first nonmagnetic layer in the track width direction.

10. The magnetic sensing element according to claim 7, wherein, side faces of the first nonmagnetic layer, the free magnetic layer and the second nonmagnetic layer are aligned with each other and form sloped side faces on the track width direction.

11. The magnetic sensing element according to claim 7, wherein, the first pinned magnetic layer comprises a first magnetic sublayer, a second magnetic sublayer and an intermediate sublayer disposed between the magnetic sublayers.

12. The magnetic sensing element according to claim 7, wherein, the first nonmagnetic layer comprises of a lower nonmagnetic sublayer and upper nonmagnetic sublayer,

side faces of the lower nonmagnetic sublayer of the first nonmagnetic material layer and the free magnetic are aligned with each other and form sloped side faces on the track width direction, and

wherein a length of the current limiting layer in the track width direction is about equal to a length of the lower nonmagnetic sublayer of the first nonmagnetic layer in the track width direction.

13. A magnetic sensing element comprising a composite film comprising, in order from the bottom:

a free magnetic layer;

a first nonmagnetic layer;

a first pinned magnetic layer; and

a first antiferromagnetic layer,

wherein an electric current flows in the composite film in a direction perpendicular to a surface of each layer of the composite film,

wherein a length of the first antiferromagnetic layer in a track width direction is larger than a length of the free magnetic layer in the track width direction,

wherein side faces of the first nonmagnetic layer and the free magnetic layer are aligned with each other and form sloped side faces on the track width direction, and

wherein the composite film further comprises;

a second nonmagnetic layer;

a second Dinned magnetic layer; and

a second antiferromagnetic layer, which are disposed under the free magnetic layer,

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

14. The magnetic sensing element according to claim 13, wherein, side faces of the first nonmagnetic layer, the free magnetic layer and the second nonmagnetic layer are aligned with each other and form sloped side faces on the track width direction.

15. The magnetic sensing element according to claim 13, wherein, the first pinned magnetic layer comprises of a first magnetic sublayer, a second magnetic sublayer and an intermediate sublayer disposed between the magnetic sublayers.