Single top spin valve heads for ultra-high recording density

• US 6,522,507 B1
• Filed: 05/12/2000
• Issued: 02/18/2003
• Est. Priority Date: 05/12/2000
• Status: Expired due to Fees

• Current Assignee: Headway Technologies Incorporated (TDK Corporation)
• Original Assignee: Headway Technologies Incorporated (TDK Corporation)
• Inventors: Tong, Ru-Ying, Li, Min, Horng, Cheng T.
• Primary Examiner(s): OMETZ, DAVID LOUIS
• Application Number:
  US09/570,017
• Time in Patent Office: 1,012 Days
• Field of Search: 360/324.1, 360/324.11, 360/324.12, 360/324.2, 296/030.7, 296/030.8, 296/030.9, 296/031.3, 296/031.4, 148/108, 148/121
• 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: G11B 5/3163 Fabrication methods or processes specially adapted for a particular head structure, e.g. using base layers for electroplating, using functional layers for masking, using energy or particle beams for shaping the structure or modifying the properties of the basic 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: Y10T 29/49044 Plural magnetic deposition layers

Abstract

A method for fabricating a single top spin valve head that is capable of reading ultra-high density recordings. Said top spin valve has a CoFe free layer for high GMR ratio, which is grown on a NiCr/Ru layer to provide better magnetic properties and has a ferromagnetically coupled CoFe/NiCr/CoFe laminated pinned layer for thermal stability and robustness.

Claims

1. A method for fabricating a single top spin valve read head for ultra-high recording densities comprising:

providing a seed layer formed over an Al₂O₃ substrate;

forming over said seed layer a buffer layer which provides an enhancement of specular reflection of conduction electrons;

forming over said buffer layer a layer of ferromagnetic material which will function as a magnetically free layer;

forming over said ferromagnetic layer a spacer layer of non-magnetic material;

forming over said spacer layer a laminated pinned layer;

forming over said laminated pinned layer a pinning layer;

forming over said pinning layer a capping layer;

annealing said fabrication a first time to fix the magnetization of the pinned layer;

annealing said fabrication a second time to reset the magnetization of the magnetically free layer.

2. The method of claim 1 wherein the seed layer is a layer of either NiCr or NiFeCr and is formed to a thickness of between 40 angstroms and 70 angstroms.

3. The method of claim 1 wherein said buffer layer is a layer of material selected from the group consisting of Ru, Rh and Ir and is formed to a thickness of between 3 angstroms and 25 angstroms.

4. The method of claim 1 wherein the non-magnetic spacer layer is a layer of Cu and is formed to a thickness of between 18 angstroms and 30 angstroms.

5. The method of claim 1 wherein the laminated pinned layer consists of a first ferromagnetic layer, on which is formed a non magnetic spacer layer, on which is formed a second ferromagnetic layer, the resulting structure being ferromagnetically coupled.

6. The method of claim 5 wherein said first ferromagnetic layer is a layer of CoFe formed to a thickness of between 8 angstroms and 20 angstroms, the non-magnetic spacer layer is a layer of NiCr formed to a thickness between 2 angstroms and 5 angstroms and the second ferromagnetic layer is a layer of CoFe formed to a thickness of between 4 angstroms and 10 angstroms.

7. The method of claim 6 wherein the thicknesses of the first and second ferromagnetic layers are in a ratio of 2:

1.

8. The method of claim 5 wherein said first ferromagnetic layer is selected from the group consisting of Co, CoFe, CoFeB and NiFe and is formed to a thickness of between 8 angstroms and 20 angstroms, the non-magnetic spacer layer is selected from the group consisting of NiCr and NiFeCr and is formed to a thickness of between 2 angstroms and 5 angstroms and the second ferromagnetic layer is selected from the group consisting of Co, CoFe, CoFeB and NiFe and is formed to a thickness of between 4 angstroms and 10 angstroms.

9. The method of claim 8 wherein the thicknesses of the two ferromagnetic layers are in a ratio of 2:

1 or approximately 2;

1.

10. The method of claim 1 wherein the pinning layer is a layer of MnPt or MnPtPd and is formed to a thickness of between 100 angstroms and 300 angstroms.

11. The method of claim 1 wherein the pinning layer is a layer of IrMn and is formed to a thickness of between 50 angstroms and 150 angstroms.

12. The method of claim 1 wherein the capping layer is a layer of material selected from the group consisting of NiCr, NiFeCr and Ta and is formed to a thickness of between 20 angstroms and 50 angstroms.

13. The method of claim 1 wherein the first anneal is at 280°

C. for 5 hours in a transverse magnetic field of 2000 Oe.

14. The method of claim 1 wherein the second anneal is at 290°

C. for 30 minutes in a magnetic field of 50 Oe in the longitudinal direction.

15. The structure of claim 1 wherein the first anneal is at 280°

C. for 5 hours in a transverse magnetic field of 2000 Oe.

16. The structure of claim 1 wherein the second anneal is at 290°

C. for 30 minutes in a magnetic field of 50 Oe in the longitudinal direction.

17. A single top spin valve read head for ultra-high recording densities comprising:

a seed layer formed on an Al₂O₃ substrate;

a buffer layer, which provides an enhancement of specular reflection of conduction electrons, formed on said seed layer;

a layer of ferromagnetic material which functions as a magnetically free layer formed over said buffer layer and having its magnetization set by a second anneal;

a spacer layer of non-magnetic material formed over said ferromagnetic layer;

a laminated pinned layer formed over said spacer layer and having its magnetization fixed by a first anneal;

a pinning layer formed over said laminated pinned layer;

a capping layer formed over said pinning layer.

18. The structure of claim 17 wherein the seed layer is a layer of either NiCr or NiFeCr and is formed to a thickness of between 40 angstroms and 70 angstroms.

19. The structure of claim 17 wherein the material of said buffer layer is a layer of material selected from the group consisting of Ru, Rh and Ir and is formed to a thickness of between 3 angstroms and 25 angstroms.

20. The structure of claim 17 wherein the non-magnetic spacer layer is a layer of Cu and is formed to a thickness of between 18 angstroms and 30 angstroms.

21. The structure of claim 17 wherein the laminated pinned layer consists of a first ferromagnetic layer, on which is formed a non magnetic spacer layer, on which is formed a second ferromagnetic layer, the resulting structure being ferromagnetically coupled.

22. The structure of claim 21 wherein said first ferromagnetic layer is a layer of CoFe deposited to a thickness of between 8 angstroms and 20 angstroms, the non-magnetic spacer layer is a layer of NiCr formed to a thickness between 2 angstroms and 5 angstroms and the second ferromagnetic layer is a layer of CoFe formed to a thickness of between 4 angstroms and 10 angstroms.

23. The structure of claim 22 wherein the thicknesses of the first and second ferromagnetic layers are in a ratio of 2:

1.

24. The structure of claim 21 wherein said first ferromagnetic layer is selected from the group consisting of Co, CoFe, CoFeB and NiFe and is formed to a thickness of between 8 angstroms and 20 angstroms, the non-magnetic spacer layer is selected from the group consisting of NiCr and NiFeCr and is formed to a thickness of between 2 angstroms and 5 angstroms and the second ferromagnetic layer is selected from the group consisting of Co, CoFe, CoFeB and NiFe and is formed to a thickness of between 4 angstroms and 10 angstroms.

25. The structure of claim 24 wherein the thicknesses of the two ferromagnetic layers are in a ratio of 2:

1 or approximately 2;

1.

26. The structure of claim 17 wherein the pinning layer is a layer of MnPt or MnPtPd and is formed to a thickness of between 100 angstroms and 300 angstroms.

27. The structure of claim 17 wherein the pinning layer is a layer of IrMn and is formed to a thickness of between 50 angstroms and 150 angstroms.

28. The structure of claim 17 wherein the capping layer is a layer of material selected from the group consisting of NiCr, NiFeCr and Ta and is formed to a thickness of between 20 angstroms and 50 angstroms.