Claims
- 1. A patterned, synthetic longitudinally exchange biased GMR sensor with narrow effective trackwidth comprising:
a substrate; a seed layer; a first layer of antiferromagnetic material formed on the seed layer, said layer being a first antiferromagnetic pinning layer; a synthetic antiferromagnetic pinned layer formed on said first antiferromagnetic pinning layer, the magnetization of said pinned layer being pinned by exchange coupling to said first antiferromagnetic pinning layer; a non-magnetic spacer layer formed on said pinned layer; a ferromagnetic free layer formed on said non-magnetic spacer layer; a non-magnetic antiferromagnetically coupling layer formed on said ferromagnetic free layer; a longitudinal biasing layer formed on said coupling layer, said biasing layer being formed as two discrete, disconnected and laterally separated ferromagnetic segments, laterally and symmetrically disposed to either side of the antiferromagnetically coupling layer and wherein said segments are separated by a portion of said biasing layer which has been rendered non-magnetic and defines a physical trackwidth and wherein the ferromagnetic segments of said biasing layer are antiferromagnetically exchange coupled to said free layer through said antiferromagnetically coupling layer to form a synthetic antiferromagnetic exchange biased configuration; a patterned antiferromagnetic pinning layer formed as two separate, disconnected segments, wherein a segment is formed on each ferromagnetic segment of said patterned, longitudinal biasing layer and is coexstensive with said segment, and wherein each of said patterned antiferromagnetic layer segments is exchange coupled to said longitudinal biasing layer segment; a conductive lead layer formed on said antiferromagnetic layer and coextensive with it.
- 2. The sensor of claim 1 wherein the first and second antiferromagnetic layers are chosen from the group of antiferromagnetic materials consisting of PtMn, IrMn, NiMn, PdPtMn and FeMn.
- 3. The sensor of claim 1 wherein the first antiferromagnetic layer is a layer of PtMn and is formed to a thickness of between approximately 80 and 150 angstroms, but preferably approximately 100 angstroms.
- 4. The sensor of claim 1 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first and second ferromagnetic layer separated by a non-magnetic antiferromagnetically coupling layer and wherein the magnetizations of said first and second ferromagnetic layers are antiparallel and transversely oriented.
- 5. The sensor of claim 4 wherein the first and second ferromagnetic layers are layers of ferromagnetic material chosen from the group consisting of CoFe, NiFe and CoFeNi.
- 6. The sensor of claim 4 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 9 angstroms but where approximately 7.5 angstroms is preferred.
- 7. The sensor of claim 4 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first layer of CoFe, formed to a thickness of between approximately 12 and 20 angstroms with 15 angstroms being preferred and a second layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with 20 angstroms being preferred, with a layer of Ru between said layers of thickness between approximately 7 and 9 angstroms with approximately 7.5 angstroms being preferred.
- 8. The sensor of claim 1 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 13 and 25 angstroms, where approximately 18 angstroms is preferred.
- 9. The sensor of claim 1 wherein the ferromagnetic free layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, and combinations thereof.
- 10. The sensor of claim 1 wherein the ferromagnetic free layer is a bilayer comprising a first ferromagnetic layer on which is formed a second ferromagnetic layer wherein said first ferromagnetic layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, and combinations thereof and wherein said second ferromagnetic layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, and combinations thereof.
- 11. The sensor of claim 11 wherein the ferromagnetic free layer is a bilayer comprising a layer of CoFe of thickness between approximately 5 and 15 angstroms, where 10 angstroms is preferred, on which is formed a layer of NiFe of thickness between approximately 15 and 30 angstroms, where approximately 20 angstroms is preferred.
- 12. The sensor of claim 1 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between 7 and 9 angstroms, where approximately 7.5 angstroms is preferred.
- 13. The sensor of claim 12 wherein the patterned ferromagnetic longitudinal biasing layer is a layer of CoFe formed to a thickness between approximately 10 and 25 angstroms with 15 angstroms being preferred and wherein said biasing layer and said ferromagnetic free layer are antiferromagnetically coupled by said antiferromagnetically coup ling layer and the magnetizations of said biasing layer and said ferromagnetic free layer are antiparallel and longitudinally oriented.
- 14. The sensor of claim 13 wherein the patterned antiferromagnetic pinning layer is a layer of IrMn formed to a thickness between approximately 35 and 55 angstroms, where approximately 40 angstroms is preferred.
- 15. The sensor of claim 1 wherein the seed layer is a layer of NiCr formed to a thickness of between approximately 50 and 65 angstroms, but where approximately 60 angstroms is preferred.
- 16. A method for fabricating a patterned, synthetic longitudinally exchange biased GMR sensor with narrow effective trackwidth comprising:
providing a substrate; forming a seed layer on said substrate; forming a first layer of antiferromagnetic material on the seed layer, said layer of antiferromagnetic material being a pinning layer; forming a synthetic antiferromagnetic pinned layer on said first antiferromagnetic pinning layer; forming a non-magnetic spacer layer on said pinned layer; forming a ferromagnetic free layer on said non-magnetic spacer layer; forming a non-magnetic antiferromagnetically coupling layer on said ferromagnetic free layer; forming a ferromagnetic, longitudinal biasing layer on said coupling layer, whereby said free layer, coupling layer and biasing layer comprise a synthetic antiferromagnetic configuration; forming a second antiferromagnetic pinning layer on said longitudinal biasing layer; forming a conductive lead layer on said antiferromagnetic layer; annealing the resulting structure with a first anneal for a first annealing time, at a first annealing temperature and in a first external magnetic field; annealing the resulting structure with a second anneal for a second annealing time, at a second annealing temperature and in a second external magnetic field; removing, by an etching process, a central portion of said conductive lead layer and the portion of said second antiferromagnetic pinning layer directly beneath said central portion, exposing, thereby, an upper surface of said longitudinal biasing layer beneath said pinning layer and forming, thereby, two discrete, disconnected and laterally separated segments, laterally and symmetrically disposed to either side of said longitudinal biasing layer and separated by the desired physical trackwidth of said sensor; oxidizing the portion of the ferromagnetic longitudinal biasing layer whose said upper surface has been exposed, said oxidation extending the entire width and thickness of said portion and destroying, thereby, the ferromagnetic properties of said layer within said oxidized portion and said oxidation being stopped by the upper surface of said non-magnetic antiferromagnetically coupling layer.
- 17. The method of claim 16 wherein the seed layer is a layer of NiCr formed to a thickness of between approximately 50 and 65 angstroms but where approximately 60 angstroms is preferred.
- 18. The method of claim 16 wherein the first and second antiferromagnetic layers are chosen from the group of antiferromagnetic materials consisting of MnPt, IrMn, NiMn, PdPtMn and FeMn.
- 19. The method of claim 17 wherein the first antiferromagnetic layer is a layer of MnPt and is formed to a thickness of between approximately 50 and 65 angstroms, but preferably approximately 100 angstroms.
- 20. The method of claim 16 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first ferromagnetic layer, a non-magnetic antiferromagnetically coupling layer formed on said first layer and a second ferromagnetic layer formed on said coupling layer.
- 21. The method of claim 20 wherein the first and second ferromagnetic layers are layers of ferromagnetic material chosen from the group consisting of CoFe, NiFe and CoFeNi.
- 22. The method of claim 20 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru.
- 23. The method of claim 22 wherein the first ferromagnetic layer i s a layer of CoFe, formed to a thickness of between approximately 12 and 20 angstroms with 15 angstroms being preferred, the second ferromagnetic layer is a layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with 20 angstroms being preferred, and the antiferromagnetically coupling layer of Ru is formed to a thickness between approximately 7 and 9 angstroms with approximately 7.5 angstroms being preferred.
- 24. The method of claim 16 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 13 and 25 angstroms, where approximately 18 angstroms is preferred.
- 25. The method of claim 16 wherein the ferromagnetic free layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, alloys thereof and laminates thereof.
- 26. The method of claim 16 wherein the first ferromagnetic layer is formed as a bilayer comprising a first ferromagnetic layer of CoFe of thickness between approximately 5 and 15 angstroms, but where 10 angstroms is preferred, on which is formed a second ferromagnetic layer of NiFe of thickness between approximately 15 and 30 angstroms, but where approximately 20 angstroms is preferred.
- 27. The method of claim 16 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 9 angstroms, but where approximately 7.5 angstroms is preferred.
- 28. The method of claim 29 wherein the ferromagnetic biasing layer is a layer of CoFe formed to a thickness between approximately 10 and 25 angstroms with approximately 15 angstroms being preferred.
- 29. The method of claim 28 wherein the second antiferromagnetic layer is a layer of IrMn formed to a thickness between approximately 35 and 55 angstroms, with approximately 40 angstroms being preferred.
- 30. The method of claim 16 wherein the first anneal sets the magnetization of the synthetic antiferromagnetic pinned layer to the transverse direction, which is the direction perpendicular to the air bearing surface of the sensor.
- 31. The method of claim 32 wherein the first anneal is for between approximately 3 and 6 hours but where approximately 5 hours is preferred, at a temperature of between approximately 250° C. and 280° C. but where 280° C. is preferred and with a magnetic field of between approximately 6 kOe and 12 kOe, but where approximately 10 kOe is preferred.
- 32. The method of claim 16 wherein the second anneal antiferromagnetically couples the ferromagnetic free layer to the longitudinal bias layer and sets its magnetization in the longitudinal direction creating, thereby, a synthetic, longitudinally biased exchange coupled configuration.
- 33. The method of claim 32 wherein the second anneal is for between approximately 30 and 60 minutes but where approximately 30 minutes is preferred, at a temperature of between approximately 250° C. and 280° C., but where approximately 250° C. is preferred and with a magnetic field of between approximately 250 and 500 Oe but where approximately 250 Oe is preferred.
- 34. A patterned, synthetic transversely exchange biased GMR sensor with narrow effective trackwidth comprising:
a substrate; a seed layer; a first layer of antiferromagnetic material formed on the seed layer, said antiferromagnetic layer being a pinning layer; a synthetic antiferromagnetic pinned layer formed on said first antiferromagnetic pinning layer; a non-magnetic spacer layer formed on said pinned layer; a ferromagnetic free layer formed on said non-magnetic spacer layer; a non-magnetic antiferromagnetically coupling layer formed on said ferromagnetic free layer; a transversely biasing layer formed on said coupling layer, said biasing layer being formed as two discrete, disconnected and laterally separated ferromagnetic segments, laterally and symmetrically disposed to either side of the antiferromagnetically coupling layer and wherein said segments are separated by a portion of said biasing layer which has been rendered non-magnetic and defines a physical trackwidth and wherein the ferromagnetic segments of said biasing layer are antiferromagnetically exchange coupled to said free layer through said antiferromagnetically coupling layer to form a synthetic antiferromagnetic exchange biased configuration; a patterned antiferromagnetic pinning layer formed as two separate, disconnected segments, wherein a segment is formed on each ferromagnetic segment of said patterned, transversely biasing layer and is coexstensive with said segment, and wherein each of said patterned antiferromagnetic layer segments is exchange coupled to said transversely biasing layer segment; a conductive lead layer formed on said antiferromagnetic layer and coextensive with it.
- 35. The sensor of claim 34 wherein the first and second antiferromagnetic layers are layers of the same antiferromagnetic material and said material is chosen from the group of antiferromagnetic materials consisting of MnPt, IrMn, NiMn, PdPtMn and FeMn.
- 36. The sensor of claim 34 wherein the first antiferromagnetic layer is a layer of MnPt and is formed to a thickness of between approximately 80 and 150 angstroms, but preferably approximately 100 angstroms.
- 37. The sensor of claim 34 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first and second ferromagnetic layer separated by a non-magnetic antiferromagnetically coupling layer and wherein the magnetizations of said first and second ferromagnetic layers are antiparallel and transversely oriented.
- 38. The sensor of claim 37 wherein the first and second ferromagnetic layers are layers of ferromagnetic material chosen from the group consisting of CoFe, NiFe and CoFeNi.
- 39. The sensor of claim 37 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru or a layer of Rh.
- 40. The sensor of claim 37 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first layer of CoFe, formed to a thickness of between approximately 12 and 20 angstroms with 15 angstroms being preferred and a second layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with 20 angstroms being preferred, with a layer of Ru between said layers of thickness between approximately 7 and 9 angstroms with approximately 7.5 angstroms being preferred.
- 41. The sensor of claim 37 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first layer of CoFe, formed to a thickness of between approximately 12 and 20 angstroms with 15 angstroms being preferred and a second layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with 20 angstroms being preferred, with a layer of Rh between said layers of thickness between approximately 4 and 6 angstroms with approximately 5 angstroms being preferred.
- 42. The sensor of claim 34 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 13 and 25 angstroms, with approximately 18 angstroms being preferred.
- 43. The sensor of claim 34 wherein the ferromagnetic free layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, CoFeNi and combinations and laminates thereof.
- 44. The sensor of claim 34 wherein the ferromagnetic free layer is a bilayer comprising a layer of CoFe of thickness between approximately 5 and 15 angstroms, where 10 angstroms is preferred, on which is formed a layer of NiFe of thickness between approximately 15 and 30 angstroms, where approximately 20 angstroms is preferred.
- 45. The sensor of claim 36 wherein the non-magnetic anti ferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 9 angstroms with approximately 7.5 angstroms being preferred.
- 46. The sensor of claim 36 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Rh formed to a thickness of between approximately 4 and 6 angstroms with approximately 5 angstroms being preferred.
- 47. The sensor of claim 34 wherein the patterned ferromagnetic transversely biasing layer is a layer of CoFe formed to a thickness between approximately 10 and 25 angstroms with approximately 15 angstroms being preferred.
- 48. The sensor of claim 49 wherein said ferromagnetic free layer and said ferromagnetic transversely biasing layer are antiferromagnetically coupled by said antiferromagnetically coupling layer and are transversely magnetized in antiparallel directions.
- 49. The sensor of claim 34 wherein the second antiferromagnetic pinning layer is a layer of MnPt formed to a thickness between approximately 80 and 150 angstroms, with approximately 40 angstroms being preferred.
- 50. The sensor of claim 34 wherein the seed layer is a layer of NiCr formed to a thickness of between approximately 50 and 65 angstroms, but where approximately 60 angstroms is preferred.
- 51. A method for fabricating a patterned, synthetic, transversely exchange biased GMR sensor with narrow effective trackwidth comprising:
providing a substrate; forming a seed layer on said substrate; forming a first layer of antiferromagnetic material on the seed layer, said layer of antiferromagnetic material being a pinning layer; forming a synthetic antiferromagnetic pinned layer on said first antiferromagnetic pinning layer; forming a non-magnetic spacer layer on said pinned layer; forming a ferromagnetic free layer on said non-magnetic spacer layer; forming a non-magnetic antiferromagnetically coupling layer on said ferromagnetic free layer; forming a ferromagnetic, longitudinal biasing layer on said coupling layer, whereby said free layer, coupling layer and biasing layer comprise a synthetic antiferromagnetic configuration; forming a second antiferromagnetic pinning layer on said longitudinal biasing layer; forming a conductive lead layer on said antiferromagnetic layer; annealing the resulting structure for an annealing time, at an annealing temperature and in an external magnetic field; removing, by an etching process, a central portion of said conductive lead layer and the portion of said second antiferromagnetic pinning layer directly beneath said central portion, exposing, thereby, an upper surface of said longitudinal biasing layer beneath said pinning layer and forming, thereby, two discrete, disconnected and laterally separated segments, laterally and symmetrically disposed to either side of said longitudinal biasing layer and separated by the desired physical trackwidth of said sensor; oxidizing the exposed portion of said ferromagnetic longitudinal biasing layer, said oxidation extending the entire width and thickness of said exposed portion and destroying the ferromagnetic properties of said layer and said oxidation being stopped by the upper surface of said non-magnetic antiferromagnetically coupling layer.
- 52. The method of claim 53 wherein the seed layer is a layer of NiCr formed to a thickness of between approximately 50 and 65 angstroms, but where approximately 60 angstroms is preferred.
- 53. The method of claim 51 wherein the first and second antiferromagnetic layers are layers of the same antiferromagnetic material and said material is chosen from the group of antiferromagnetic materials consisting of PtMn, IrMn, NiMn, PdPtMn and FeMn.
- 54. The method of claim 53 wherein the first antiferromagnetic layer is a layer of PtMn and is formed to a thickness of between approximately 80 and 150 angstroms, but preferably approximately 100 angstroms.
- 55. The method of claim 51 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first and second ferromagnetic layer separated by a non-magnetic antiferromagnetically coupling layer.
- 56. The method of claim 55 wherein the first and second ferromagnetic layers are layers of ferromagnetic material chosen from the group consisting of CoFe, NiFe and CoFeNi.
- 57. The method of claim 56 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru or a layer of Rh.
- 58. The method of claim 55 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first layer of CoFe, formed to a thickness of between approximately 12 and 20 angstroms with 15 angstroms being preferred and a second layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with 20 angstroms being preferred, with a layer of Ru between said layers of thickness between approximately 7 and 9 angstroms with approximately 7.5 angstroms being preferred.
- 59. The method of claim 55 wherein the synthetic antiferromagnetic pinned layer is a trilayer comprising a first layer of CoFe, formed to a thickness of between approximately 15 and 20 angstroms with 15 angstroms being preferred and a second layer of CoFe formed to a thickness of between approximately 15 and 25 angstroms with approximately 20 angstroms being preferred, with a layer of Rh between said layers of thickness between approximately 4 and 6 angstroms with 5 angstroms being preferred.
- 60. The method of claim 51 wherein the non-magnetic spacer layer is a layer of Cu formed to a thickness of between approximately 16 and 25 angstroms, with approximately 18 angstroms being preferred.
- 61. The method of claim 51 wherein the ferromagnetic free layer is a layer of ferromagnetic material chosen from the group consisting of CoFe, NiFe, alloys thereof and laminates thereof.
- 62. The method of claim 51 wherein the ferromagnetic layer is formed as a bilayer comprising a first ferromagnetic layer of CoFe of thickness between approximately 5 and 15 angstroms, but where 10 angstroms is preferred, on which is formed a layer of NiFe of thickness between approximately 15 and 30 angstroms, but where approximately 20 angstroms is preferred.
- 63. The method of claim 51 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Ru formed to a thickness of between approximately 7 and 9 angstroms, but where approximately 7.5 angstroms is preferred.
- 64. The method of claim 51 wherein the non-magnetic antiferromagnetically coupling layer is a layer of Rh formed to a thickness of between approximately 4 and 6 angstroms, but where approximately 7.5 angstroms is preferred.
- 65. The method of claim 51 wherein the ferromagnetic biasing layer is a layer of CoFe formed to a thickness between approximately 10 and 25 angstroms with approximately 15 angstroms being preferred.
- 66. The method of claim 54 wherein the second antiferromagnetic layer is a layer of PtMn formed to a thickness between approximately 35 and 55 angstroms, where approximately 40 angstroms is preferred.
- 67. The method of claim 51 wherein the anneal antiferromagnetically exchange couples the ferromagnetic layers of the pinned layer and sets the antiparallel magnetizations of said ferromagnetic layers to the transverse direction, which is the direction perpendicular to the air bearing surface of the sensor and simultaneously antiferromagnetically couples the ferromagnetic free layer and the ferromagnetic biasing layer and sets the antiparallel magnetizations of said free and biasing layers also to the transverse direction..
- 68. The method of claim 53 wherein the anneal is 5 hour 280° C. anneal in a transverse external magnetic field of approximately 10 kOe
- 69. A patterned, synthetic transversely exchange biased GMR sensor with narrow effective trackwidth comprising:
a substrate; a seed layer; a layer of antiferromagnetic material formed on the seed layer, said antiferromagnetic layer being a pinning layer; a synthetic antiferromagnetic pinned layer formed on said first antiferromagnetic pinning layer; a non-magnetic spacer layer formed on said pinned layer; a ferromagnetic free layer formed on said non-magnetic spacer layer; a non-magnetic antiferromagnetically coupling layer formed on said ferromagnetic free layer; a transversely biasing layer formed on said coupling layer, said biasing layer being formed as two discrete, disconnected and laterally separated ferromagnetic segments, laterally and symmetrically disposed to either side of the antiferromagnetically coupling layer and defining, thereby, a physical trackwidth and wherein the ferromagnetic segments of said biasing layer are magnetized in opposite transverse directions and wherein each said segment is antiferromagnetically exchange coupled to a portion of said free layer beneath said segment through said antiferromagnetically coupling layer to form a synthetic antiferromagnetic exchange biased configuration having oppositely directed magnetizations at each side of said configuration; a patterned antiferromagnetic pinning layer formed as two separate, disconnected segments, wherein a segment is formed on each ferromagnetic segment of said patterned, transversely biasing layer and is coexstensive with said segment, and wherein each of said patterned antiferromagnetic layer segments is exchange coupled to said transversely biasing layer segment; a conductive lead layer formed on each of said antiferromagnetic pinning layer segments and coextensive with it.
- 70. The sensor of claim 46 wherein the ferromagnetic free layer is a bilayer comprising a layer of CoFe of thickness between approximately 5 and 15 angstroms, where 10 angstroms is preferred, on which is formed a layer of NiFe of thickness between approximately 15 and 30 angstroms, where approximately 20 angstroms is preferred.
- 71. The sensor of claim 36 wherein the patterned ferromagnetic transversely biasing layer is a layer of CoFe formed to a thickness between approximately 10 and 25 angstroms with approximately 15 angstroms being preferred.
- 72. The sensor of claim 69 wherein each of the patterned antiferromagnetic layer segments is a layer of IrMn formed to a thickness between approximately 35 angstroms and 55 angstroms, where approximately 40 angstroms is preferred.
- 73. A method for fabricating a patterned, synthetic transversely exchange biased GMR sensor with narrow effective trackwidth comprising:
providing a substrate; forming a seed layer on said substrate; forming a layer of antiferromagnetic material on the seed layer, said layer of antiferromagnetic material being a pinning layer; forming a synthetic antiferromagnetic pinned layer on said first antiferromagnetic pinning layer; forming a non-magnetic spacer layer on said pinned layer; forming a ferromagnetic free layer on said non-magnetic spacer layer; forming a non-magnetic antiferromagnetically coupling layer on said ferromagnetic free layer; forming a ferromagnetic, transversely biasing layer on said coupling layer; magnetizing and pinning the synthetic antiferromagnetic pinned layer with the first antiferromagnetic pinning layer; magnetizing and antiferromagnetically pinning with a first patterned antiferromagnetic pinning layer a first portion of said biasing layer in a first transverse direction using a first patterning and magnetizing process whereby said first portion is magnetized and exchange coupled to a first portion of the ferromagnetic free layer; magnetizing and antiferromagnetically pinning with a second patterned antiferromagnetic pinning layer a second portion of said biasing layer in a second transverse direction using a second patterning and magnetizing process whereby said second portion is magnetized in an opposite direction to said first portion and exchange coupled to a second portion of the ferromagnetic free layer removing, by an etching process, a central portion of said biasing layer which is situated between said pinned and magnetized first and second portions to form a trackwidth region of the sensor; forming a conductive lead layer over each of the antiferromagnetically pinned first and second portions of the transversely biasing layer.
- 74. The method of claim 73 wherein the first patterning and magnetizing process comprises:
forming a layer of photoresist material over the biasing layer; removing a portion of said photoresist material to expose a portion of the biasing layer extending longitudinally from one lateral edge of the layer, less than half the longitudinal width of the layer; cleaning said exposed portion with an etching process; depositing additional ferromagnetic material to restore any ferromagnetic material removed by the etching process; forming a layer of antiferromagnetic material over said exposed portion to serve as a pinning layer; annealing the structure so formed at a first annealing temperature for a first annealing time in a first transverse magnetic field directed in a first direction; removing the remaining photoresist.
- 75. The method of claim 73 wherein the second patterning and magnetizing process comprises:
forming a layer of photoresist material over the biasing layer; removing a portion of said photoresist material having the same approximate dimensions as the layer removed in the first patterning and magnetizing process, but symmetrically disposed on the opposite lateral end of the biasing layer; cleaning said exposed portion with an etching process; depositing additional ferromagnetic material to restore any ferromagnetic material removed by the etching process; forming a layer of antiferromagnetic material over said exposed portion to serve as a pinning layer; annealing the structure so formed at a second annealing temperature for a second annealing time in a second transverse magnetic field oppositely directed to the first transverse magnetic field of the first patterning and magnetizing process; removing any remaining photoresist from the structure so formed;
- 76. The process of claim 74 wherein the layer of antiferromagnetic material is a layer of IrMn deposited to a thickness of between approximately 35 and 55 angstroms with approximately 40 angstroms being preferred.
- 77. The process of claim 75 wherein the layer of antiferromagnetic material is a layer of IrMn deposited to a thickness of between approximately 35 and 55 angstroms with approximately 40 angstroms being preferred.
- 78. The process of claim 76 wherein the first anneal is for between approximately 30 and 60 minutes but where approximately 30 minutes is preferred, at a temperature of between approximately 250° C. and 280° C., but where 250° C. is preferred and with a magnetic field of between approximately 250 and 500 Oe but where 250 Oe is preferred.
- 79. The process of claim 77 wherein the second anneal is for between approximately 30 and 60 minutes but where approximately 30 minutes is preferred, at a temperature of between approximately 250° C. and 280° C., but where 250° C. is preferred and with a magnetic field of between approximately 250 and 500 Oe but where 250 Oe is preferred.
RELATED PATENT APPLICATION
[0001] This application is related to Docket No. HT01-032, Serial No. (______) filing date (______), to Docket No. HT01-037, Ser. No. 10/077064, filing date Feb. 15, 2002 and to Docket No. HT01-020, Serial No. (______) filing date (______), assigned to the same assignee as the current invention.