Current perpendicular to plane differential magnetoresistance read head design using a current confinement structure proximal to an air bearing surface
View Patent ↗A current to perpendicular to plane (CPP) differential magnetoresistance (DMR) read head using current confinement proximal to an air bearing surface (ABS) is disclosed. The CPP DMR read head includes a first electrically conductive lead, a first MR sensor formed on the first lead, and a non-magnetic electrically conductive spacer formed on the first MR sensor proximate to the ABS. The CPP DMR read head further includes insulating material on the first MR sensor distal to the ABS. A second MR sensor is formed in contact with the conductive spacer such that the second MR sensor is in electrical contact with the first MR sensor proximate to the ABS and is electrically isolated from the first MR sensor distal to the ABS. A second electrically conductive lead is in contact with the second MR sensor. Sense current injected into the first and the second MR sensor is confined proximate to the ABS.
1. A current perpendicular to plane (CPP) differential magnetoresistance (DMR) read head comprising:
a first electrically conductive lead;
a first MR sensor having a back edge and in contact with the first conductive lead;
a second MR sensor;
a non-magnetic electrically conductive spacer in contact and in between the first MR sensor and the second MR sensor proximal to an air bearing surface (ABS) and wherein the conductive spacer is not in contact with the first MR sensor and the second MR sensor distal to the ABS;
insulating material in between the first MR sensor and the second MR sensor distal to the ABS such that the first MR sensor and the second MR sensor are in electrical contact proximal to the ABS and are electrically isolated distal to the ABS; and
a second electrically conductive lead in contact with the second MR sensor.
2. The CPP DMR read head of claim 1 wherein the first MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
3. The CPP DMR read head of claim 1 wherein the second MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
4. The CPP DMR read head of claim 1 wherein at least one of the first MR sensor and the second MR sensor comprises at least one of a giant MR sensor and a tunneling MR sensor.
5. The CPP DMR read head of claim 1 further including an electronic lapping guide having a back edge coplanar with the back edge of the conductive spacer.
6. The CPP DMR read head of claim 1 wherein at least one of the first conductive lead and the second conductive lead comprise a ferromagnetic shield.
7. A current perpendicular to plane (CPP) differential magnetoresistance (DMR) read head comprising:
a first electrically conductive lead;
a first MR sensor formed on the first conductive lead;
a second MR sensor;
a non-magnetic electrically conductive spacer sandwiched between the first MR sensor and the second MR sensor to define a contact region;
insulating material sandwiched between the first MR sensor and the second MR sensor distal to the ABS to define an isolation region where the first MR sensor and the second MR sensor are in electrical contact in the contact region and are not in electrical contact in the isolation region; and
a second electrically conductive lead in contact with the second MR sensor.
8. The CPP DMR read head of claim 7 wherein the contact region of the conductive spacer contacts the first MR sensor along a length of between about 5 to 30 nanometers proximate to the ABS.
9. The CPP DMR read head of claim 7 wherein the contact region of the conductive spacer contacts the second MR sensor along a length of between about 5 to 30 nanometers proximate to the ABS.
10. The CPP DMR read head of claim 7 wherein at least one of the first MR sensor and the second MR sensor comprises at least one of a giant MR sensor and a tunneling MR sensor.
11. The CPP DMR read head of claim 7 further including an electronic lapping guide having a back edge coplanar with a back edge of the conductive spacer.
12. The CPP DMR read head of claim 7 wherein at least one of the first conductive lead and the second conductive lead comprise a ferromagnetic shield.
13. A magnetic disk drive system comprising:
a magnetic disk; and
a current perpendicular to plane (CPP) differential magnetoresistance (DMR) read head comprising:
a first electrically conductive lead;
a first MR sensor having a back edge and in contact with the first conductive lead;
a second MR sensor;
a non-magnetic electrically conductive spacer in contact and in between the first MR sensor and the second MR sensor proximal to an air bearing surface (ABS) and wherein the conductive spacer is not in contact with the first MR sensor and the second MR sensor distal to the ABS;
insulating material in between the first MR sensor and the second MR sensor distal to the ABS such that the first MR sensor and the second MR sensor are in electrical contact proximal to the ABS and are electrically isolated distal to the ABS; and
a second electrically conductive lead in contact with the second MR sensor.
14. The magnetic disk drive system of claim 13 wherein the first MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
15. The magnetic disk drive system of claim 13 wherein the second MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
16. The magnetic disk drive system of claim 13 wherein at least one of the first MR sensor and the second MR sensor comprises at least one of a giant MR sensor and a tunneling MR sensor.
17. The magnetic disk drive system of claim 13 further including an electronic lapping guide having a back edge coplanar with the back edge of the conductive spacer.
18. The magnetic disk drive system of claim 13 wherein at least one of the first conductive lead and the second conductive lead comprise a ferromagnetic shield.
19. A method of fabricating current perpendicular to plane (CPP) differential magnetoresistance (DMR) read heads, the method comprising:
forming a first MR sensor on a first electrically conductive lead, wherein the first MR sensor has a back edge distal from an air bearing surface (ABS);
forming a non-magnetic electrically conductive spacer on the first MR sensor proximal to an air bearing surface (ABS) to exposes a portion of the first MR sensor proximal to the back edge;
forming insulating material on the first MR sensor to cover the exposed portion of the first MR sensor proximal to the back edge;
forming a second MR sensor on the conductive spacer and the insulating material; and
forming a second electrically conductive lead on the second MR sensor.
20. The method of claim 19 wherein the first MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
21. The method of claim 19 wherein the second MR sensor contacts the conductive spacer along a length of between about 5 to 30 nanometers proximate to the ABS.
22. The method of claim 19 wherein at least one of the first MR sensor and the second MR sensor comprises at least one of a giant MR sensor and a tunneling MR sensor.
23. The method of claim 19 further including an electronic lapping guide having a back edge coplanar with a back edge of the conductive spacer.
24. The method of claim 19 wherein at least one of the first conductive lead and the second conductive lead comprises a ferromagnetic shield.