Magnetoresistive sensor having specular sidewall layers

• US 20050099738A1
• Filed: 11/06/2003
• Published: 05/12/2005
• Est. Priority Date: 11/06/2003
• Status: Active Grant

• Current Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Original Assignee: Seagate Technology LLC (Seagate Technology Holdings Plc)
• Inventors: Xue, Song S., Kautzky, Michael C., Anderson, Paul E., Ryan, Patrick J., Tang, Xuefei
• Granted Patent: US 7,158,353 B2
• Time in Patent Office: Days
• US Class Current: 360/324.1
• 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: G11B 2005/3996 large or giant magnetoresistive effects [GMR], e.g. as generated in spin-valve [SV] devices
• CPC Class Codes: G11B 5/3906 Details related to the use of magnetic thin film layers or to their effects

Abstract

A transducing head includes a multilayered magnetoresistive sensor having an air bearing sidewall opposite aback sidewall and a first sidewall opposite a second sidewall. A specular layer is positioned on at least one of the air bearing sidewall, the back sidewall, the first sidewall, and the second sidewall. Each sidewall is transverse to the layers of the magnetoresistive sensor.

Claims

1. A transducing head comprising:

a multilayered magnetoresistive sensor having an air bearing sidewall opposite a back sidewall and a first sidewall opposite a second sidewall, each of the sidewalls being transverse to the layers of the magnetoresistive sensor; and

a first specular layer positioned upon a sidewall selected from the group consisting of the air bearing sidewall and the back sidewall.

2. The transducing head of claim 1 wherein the first specular layer is an oxidized metallic layer.

3. The transducing head of claim 1 and further comprising a copper layer positioned between the first specular layer and the selected sidewall.

4. The transducing head of claim 3 wherein the copper layer has a thickness less than about 10 Angstroms.

5. The transducing head of claim 1 and further comprising a second specular layer positioned upon the unselected sidewall.

6. The transducing head of claim 5 wherein the specular layer positioned upon the air bearing sidewall has a thickness in a range of about 5 Angstroms to about 20 Angstroms.

7. The transducing head of claim 5 wherein the specular layer positioned upon the back sidewall has a thickness in a range of about 5 Angstroms to about 100 Angstroms.

8. The transducing head of claim 1 and further comprising first and second side specular layers respectively positioned upon the first and second sidewalls.

9. The transducing head of claim 1 wherein the magnetoresistive sensor is a current-perpendicular-to-plane magnetoresistive sensor.

10. The transducing head of claim 9 and further comprising first and second side specular layers respectively positioned upon the first and second sidewalls, wherein the first and second side specular layers are oxidized metallic layers.

11. The transducing head of claim 10 wherein the first and second side specular layers each have a thickness in a range of about 5 Angstroms to about 100 Angstroms.

12. The transducing head of claim 10 and further comprising a first copper layer positioned between the first side specular layer and the first sidewall and a second copper layer positioned between the second side specular layer and the second sidewall.

13. The transducing head of claim 12 wherein the first and second copper layers each have a thickness less than about 10 Angstroms.

14. The transducing head of claim 9 wherein at least one layer of the magnetoresistive sensor is a half metal layer.

15. The transducing head of claim 14 wherein the at least one half metal layer is formed of a material selected from the group consisting of Fe₃O₄, CrO₂, NiMnSb, LaBaMnO₃, Sr₂FeMoO₆, and Sr₂FeReO₆.

16. The transducing head of claim 14 wherein the at least one half metal layer has a thickness in a range of about 5 Angstroms to about 50 Angstroms.

17. The transducing head of claim 1 wherein the magnetoresistive sensor is a current-in-plane magnetoresistive sensor.

18. The transducing head of claim 17 and further comprising first and second side specular layers respectively positioned upon the first and second sidewalls, wherein the first and second side specular layers are formed of a specular material having high spin polarization and high electrical conductivity.

19. The transducing head of claim 18 wherein the first and second side specular layers of formed of a cobalt-iron alloy having an iron composition in a range of about 10 atomic percent to about 80 atomic percent.

20. The transducing head of claim 18 wherein the first and second side specular layers each have a thickness in a range of about 20 Angstroms to about 100 Angstroms.

21. The transducing head of claim 17 wherein at least one layer of the magnetoresistive sensor is an in-plane specular layer positioned adjacent a free layer of the magnetoresistive sensor.

22. The transducing head of claim 21 wherein the in-plane specular layer is an oxidized metallic layer.

23. The transducing head of claim 21 wherein the in-plane specular layer is a partially oxidized magnetic layer.

24. The transducing head of claim 21 wherein the in-plane specular layer has a thickness in a range of about 5 Angstroms to about 20 Angstroms.

25. A multilayered magnetoresistive sensor having an air bearing sidewall opposite a back sidewall and a first sidewall opposite a second sidewall, each of the air bearing sidewall, the back sidewall, and the first and second sidewalls is transverse to the layers of the magnetoresistive sensor, the magnetoresistive sensor comprising:

an air bearing specular layer positioned upon the air bearing sidewall;

a back specular layer positioned upon the back sidewall;

a first sidewall specular layer positioned upon the first sidewall; and

a second sidewall specular layer positioned upon the second sidewall.

26. The magnetoresistive sensor of claim 25 wherein each specular layer is separated from the sidewall upon which it is positioned by a copper layer having a thickness less than about 5 Angstroms.

27. The magnetoresistive sensor of claim 25 wherein the air bearing specular layer is an oxidized metallic layer having a thickness in a range of about 5 Angstroms to about 20 Angstroms.

28. The magnetoresistive sensor of claim 25 wherein the back specular layer is an oxidized metallic layer having a thickness in a range of about 5 Angstroms to about 100 Angstroms.

29. The magnetoresistive sensor of claim 25 wherein the first and second sidewall specular layers are oxidized metallic layers having a thickness in a range of about 5 Angstroms to about 100 Angstroms.

30. The magnetoresistive sensor of claim 25 wherein the first and second sidewall specular layers are cobalt-iron layers having an iron composition in a range of about 10 atomic percent to about 80 atomic percent and having a thickness in a range of about 20 Angstroms to about 100 Angstroms.

31. A current-in-plane magnetoresistive sensor comprising at least four sidewalls transverse to a plurality of layers forming the magnetoresistive sensor, at least one of the four sidewalls having a specular layer positioned thereon.

32. The current-in-plane magnetoresistive sensor of claim 31 wherein the at least four sidewalls comprise an air bearing sidewall opposite a back sidewall and a first sidewall opposite a second sidewall.

33. The current-in-plane magnetoresistive sensor of claim 32 wherein the specular layer is positioned upon the air bearing sidewall and comprises an oxidized metallic layer having a thickness in a range of about 5 Angstroms to about 20 Angstroms.

34. The current-in-plane magnetoresistive sensor of claim 33 wherein specular layer is separated from the air bearing sidewall by a copper layer having a thickness less than about 5 Angstroms.

35. The current-in-plane magnetoresistive sensor of claim 32 wherein the specular layer is positioned upon the back sidewall and comprises an oxidized metallic layer having a thickness in a range of about 5 Angstroms to about 100 Angstroms.

36. The current-in-plane magnetoresistive sensor of claim 32 wherein specular layer is separated from the back sidewall by a copper layer having a thickness less than about 5 Angstroms.

37. The current-in-plane magnetoresistive sensor of claim 32 wherein the specular layer is positioned upon the first sidewall and is formed of a specular material having high spin polarization and high electrical conductivity.

38. The current-in-plane magnetoresistive sensor of claim 32 wherein the specular layer is positioned the first sidewall and comprises a cobalt-iron layer having an iron composition in a range of about 10 atomic percent to about 80 atomic percent and having a thickness in a range of about 20 Angstroms to about 100 Angstroms.

39. The current-in-plane magnetoresistive sensor of claim 32 wherein at least one layer of the magnetoresistive sensor is an in-plane specular layer positioned adjacent a free layer of the magnetoresistive sensor and having a thickness in a range of about 5 Angstroms to about 20 Angstroms.

40. The current-in-plane magnetoresistive sensor of claim 39 wherein the in-plane specular layer is an oxidized metallic layer.

41. The current-in-plane magnetoresistive sensor of claim 39 wherein the in-plane specular layer is a partially oxidized magnetic layer.

42. A multilayered magnetoresistive device comprising:

a top surface opposite a bottom surface;

a sidewall connecting the top surface to the bottom surface, the sidewall being transverse to the layers of the magnetoresistive and extending a perimeter about the magnetoresistive sensor;

a specular layer positioned upon the sidewall.

43. A magnetic memory device comprising the magnetoresistive device of claim 42.