Free layer for CPP GMR having iron rich NiFe

• US 7,390,529 B2
• Filed: 05/26/2004
• Issued: 06/24/2008
• Est. Priority Date: 05/26/2004
• Status: Expired due to Fees

• Current Assignee: Headway Technologies Incorporated
• Original Assignee: Headway Technologies Incorporated
• Inventors: Chen, Yu-Hsia, Tong, Ru-Ying, Li, Min, Horng, Cheng T., Han, Cherng Chyi
• Primary Examiner(s): Bashore; Alain L
• Application Number:
  US10/854,651
• Publication Number:
  US 20050264954A1
• Time in Patent Office: 1,490 Days
• Field of Search: 427/127, 427/128, 427/132, 427/131, 296/030.7, 360/324.12
• US Class Current: 427/127
• 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: B82Y 40/00 Manufacture or treatment of nanostructures
• 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 5/3929 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: H01F 10/3272 by use of anti-parallel coupled [APC] ferromagnetic layers, e.g. artificial ferrimagnets [AFI], artificial [AAF] or synthetic [SAF] anti-ferromagnets
• CPC Class Codes: H01F 41/302 for applying spin-exchange-coupled multilayers, e.g. nanostructured superlattices spin-exchange-coupled multilayers H01F10/32
• CPC Class Codes: Y10T 29/49032 Fabricating head structure or component thereof
• CPC Class Codes: Y10T 29/49043 Depositing magnetic layer or coating
• CPC Class Codes: Y10T 29/49044 Plural magnetic deposition layers

Abstract

By using a free layer that includes a NiFe layer containing between 65 and 72 atomic percent iron, an improved CPP GMR device has been created. The resulting structure yields a higher CPP GMR ratio than prior art devices, while maintaining free layer softness and acceptable magnetostriction. A process for manufacturing the device is also described.

Claims

1. A process to manufacture a CPP GMR read head, comprising:

depositing, in unbroken succession on a lower lead layer, a seed layer and a pinning layer;

on said pinning layer, depositing a pinned layer;

depositing a non magnetic spacer layer on said pinned layer;

on said non magnetic spacer layer, depositing a free layer that further comprises a layer of nickel iron, containing between about 65 and 72 atomic percent iron, and a layer of cobalt iron containing about 25 atomic percent iron; and

on said free layer, depositing a capping layer and then an upper lead layer, thereby forming said CPP GMR read head.

2. The process described in claim 1 wherein said pinning layer is IrMn deposited to a thickness between 45 and 80 Angstroms.

3. The process described in claim 1 wherein said layer of nickel iron is deposited to a thickness of between about 15 and 50 Angstroms.

4. The process described in claim 1 wherein said layer of cobalt iron is deposited to a thickness of between about 3 and 15 Angstroms.

5. The process described in claim 1 wherein said pinned layer is a synthetic antiferromagnet that comprises oppositely magnetized ferromagnetic layers separated by an antiferromagnetic coupling layer.

6. A process to manufacture a CPP GMR read head, comprising:

depositing, in unbroken succession on a lower lead layer, a seed layer and a pinning layer;

on said pinning layer, depositing a pinned layer;

depositing a non magnetic spacer layer on said pinned layer;

on said non magnetic spacer layer, depositing a free layer that further comprises a layer of nickel iron, containing between about 65 and 72 atomic percent iron, and a layer of cobalt iron containing between about 9 and 75 atomic percent iron; and

on said free layer, depositing a capping layer and then an upper lead layer, thereby forming said CPP GMR read head.

7. The process described in claim 6 wherein said pinning layer is IrMn deposited to a thickness between 45 and 80 Angstroms.

8. The process described in claim 6 wherein said layer of nickel iron is deposited to a thickness of between about 15 and 50 Angstroms.

9. The process described in claim 6 wherein said layer of cobalt iron is deposited to a thickness of between about 3 and 15 Angstroms.

10. The process described in claim 6 wherein said pinned layer is a synthetic antiferromagnet that comprises oppositely magnetized ferromagnetic layers separated by an antiferromagnetic coupling layer.

11. A process to manufacture a CPP GMR read head, comprising:

depositing, in unbroken succession on a lower lead layer, a seed layer and a pinning layer;

on said pinning layer, depositing a pinned layer;

depositing a non magnetic spacer layer on said pinned layer;

on said non magnetic spacer layer, depositing a free layer that is a layer of nickel iron, containing between about 65 and 72 atomic percent iron; and

on said free layer, depositing a capping layer and then an upper lead layer, thereby forming said CPP GMR read head.

12. The process described in claim 11 wherein said pinning layer is IrMn deposited to a thickness between 45 and 80 Angstroms.

13. The process described in claim 11 wherein said layer of nickel iron is deposited to a thickness of between about 15 and 50 Angstroms.

14. The process described in claim 11 wherein said pinned layer is a synthetic antiferromagnet that comprises oppositely magnetized ferromagnetic layers separated by an antiferromagnetic coupling layer.

15. A process to manufacture a CPP GMR read head, comprising:

depositing, in unbroken succession on a lower lead layer, a seed layer and a pinning layer;

on said pinning layer, depositing a pinned layer;

depositing a non magnetic spacer layer on said pinned layer;

on said non magnetic spacer layer, depositing a free layer that further comprises a first layer of nickel iron, containing between about 65 and 72 atomic percent iron, and a second layer of nickel iron containing between about 16 and 21 atomic percent iron; and

on said free layer, depositing a capping layer and then an upper lead layer, thereby forming said CPP GMR read head.

16. The process described in claim 15 wherein said pinning layer is IrMn deposited to a thickness between 45 and 80 Angstroms.

17. The process described in claim 15 wherein said first layer of nickel iron is deposited to a thickness of between about 5 and 30 Angstroms.

18. The process described in claim 15 wherein said second layer of nickel iron is deposited to a thickness of between about 10 and 45 Angstroms.

19. The process described in claim 15 wherein said pinned layer is a synthetic antiferromagnet that comprises oppositely magnetized ferromagnetic layers separated by an antiferromagnetic coupling layer.