In-situ exchange biased GMR head for ultra-high density recording with pinning layer-only anneal
View Patent ↗A process for manufacturing a GMR read element of a read/write head for a disk drive having pattern exchange biasing for longitudinal stabilization. An in situ or ex situ GMR anneal of the pinned layer occurs after only the AFM pinning layer and the first pinned layer have been deposited. After the anneal, the upper surface of the first pinned layer is milled with low energy ions to remove oxidation and SIMS inspection determines the amount of oxidation removed and the amount of surface modification required for smoothing. After this, the remaining layers are deposited through the exchange bias layer. A second anneal is then performed at a somewhat lower temperature than the GMR anneal. In this manner, the entire stack is not subjected to the GMR anneal, the upper surface of the first pinned layer can be optimized, and the interface between the free layer and the exchange biased layer is not disturbed.
1. A method for producing a read element of a read/write head for a disk drive, comprising:
depositing a pinning layer;
depositing a pinned layer on top of the pinning layer to form a partial stack;
annealing the partial stack while applying a magnetic field in a first direction;
then depositing an electrically-conductive spacer layer on top of the partial stack after annealing the partial stack;
depositing a free layer on top of the partial stack;
depositing an exchange bias layer on top of the partial stack to form a stack; and
annealing the stack while applying a magnetic field in a second direction, different than the first direction;
wherein the pinned layer deposited before the first anneal is the first pinned layer in a synthetic pinned layer structure, wherein the remaining layers of the synthetic pinned layer structure are deposited subsequent to the first anneal.
2. A method as defined in claim 1 , wherein the first anneal is performed in situ.
3. A method as defined in claim 1 , wherein the first anneal is performed ex situ.
4. A method as defined in claim 1 , further including milling the upper surface of the first pinned layer after the first anneal.
5. A method as defined in claim 4 , wherein the milling is a low energy ion milling operation.
6. A method as defined in claim 4 , further including smoothing the upper surface of the first pinned layer after milling the upper surface of the first pinned layer.
7. A method as defined in claim 1 , further including smoothing the upper surface of the first pinned layer after the first anneal.
8. A method as defined in claim 7 , wherein the smoothing includes ion beam oxidation.
9. A method as defined in claim 7 , wherein the smoothing includes a gas clustering technique.
10. A method as defined in claim 1 , further including etching away a portion of the exchange bias layer to leave a pattern of exchange bias material and then depositing insulator material where the portion of the exchange bias layer was etched away.
11. A method as defined in claim 10 , wherein the etching is performed with reactive ions.
12. A method as defined in claim 1 , wherein the exchange bias layer includes platinum manganese.
13. A method as defined in claim 1 , wherein the exchange bias layer includes a high blocking temperature material that can be annealed at a temperature that is less than the temperature that would change the magnetization direction of the first pinned layer.
14. A method for producing a read element of a read/write head for a disk drive, comprising:
depositing a pinning layer;
depositing a pinned layer on top of the pinning layer to form a partial stack;
annealing the partial stack while applying a magnetic field in a first direction prior to depositing other layers;
then depositing an electrically-conductive spacer layer on top of the partial stack after annealing the partial stack; and
depositing a free layer;
wherein the pinned layer deposited before the anneal is the first pinned layer in a synthetic pinned layer structure, wherein the remaining layers of the synthetic pinned layer structure are deposited subsequent to the anneal.
15. A method as defined in claim 14 , wherein the first anneal is performed in situ.
16. A method as defined in claim 14 , wherein the first anneal is performed ex situ.
17. A method as defined in claim 14 , further including milling the upper surface of the first pinned layer after the first anneal.
18. A method as defined in claim 17 , wherein the milling is a low energy ion milling operation.
19. A method as defined in claim 17 , further including smoothing the upper surface of the first pinned layer after milling the upper surface of the first pinned layer.
20. A method as defined in claim 14 , further including smoothing the upper surface of the first pinned layer after the first anneal.
21. A method as defined in claim 20 , wherein the smoothing includes ion beam oxidation.
22. A method as defined in claim 20 , wherein the smoothing includes a gas clustering technique.
23. A method as defined in claim 14 , further including depositing an exchange bias layer and annealing the stack while applying a magnetic field in a second direction, different than the first direction.
24. A method as defined in claim 23 , further including etching away a portion of the exchange bias layer to leave a pattern of exchange bias material and then depositing insulator material where the portion of the exchange bias layer was etched away.
25. A method as defined in claim 24 , wherein the etching is performed with reactive ions.
26. A method as defined in claim 23 , wherein the exchange bias layer includes platinum manganese.
27. A method as defined in claim 23 , wherein the exchange bias layer includes a high blocking temperature material that can be annealed at a temperature that is less than the temperature that would change the magnetization direction of the first pinned layer.
28. A method for producing a read element of a read/write head for a disk drive, comprising:
depositing a pinning layer;
depositing a pinned layer;
setting the magnetization direction of the pinned layer;
wherein the pinned layer deposited before the magnetization direction is set is the first pinned layer in a synthetic pinned layer structure, wherein the remaining layers of the synthetic pinned layer structure are deposited subsequent to the setting of the magnetization direction of the first pinned layer;
then depositing an electrically-conductive spacer layer on top of the pinned layer after setting the magnetization direction thereof;
depositing a free layer on top of the spacer layer;
depositing an exchange bias layer; and
setting the magnetization direction of the free layer.
29. A method as defined in claim 28 , wherein the setting of the magnetization direction of the first pinned layer is performed in situ.
30. A method as defined in claim 28 , wherein the setting of the magnetization direction of the first pinned layer is performed ex situ.
31. A method as defined in claim 28 , further including milling the upper surface of the first pinned layer after the setting of the magnetization direction of the first pinned layer.
32. A method as defined in claim 31 , wherein the milling is a low energy ion milling operation.
33. A method as defined in claim 31 , further including smoothing the upper surface of the first pinned layer after milling the upper surface of the first pinned layer.
34. A method as defined in claim 28 , further including smoothing the upper surface of the first pinned layer after the setting of the magnetization direction of the first pinned layer.
35. A method as defined in claim 34 , wherein the smoothing includes ion beam oxidation.
36. A method as defined in claim 34 , wherein the smoothing includes a gas clustering technique.
37. A method as defined in claim 28 , further including etching away a portion of the exchange bias layer to leave a pattern of exchange bias material and then depositing insulator material where the portion of the exchange bias layer was etched away.
38. A method as defined in claim 37 , wherein the etching is performed with reactive ions.
39. A method as defined in claim 28 , wherein the exchange bias layer includes platinum manganese.
40. A method as defined in claim 28 , wherein the exchange bias layer includes a high blocking temperature material that can be annealed at a temperature that is less than the temperature that would change the magnetization direction of the first pinned layer.
41. A method for producing a read element of a read/write head for a disk drive, comprising:
depositing a pinning layer;
depositing a first pinned layer of a synthetic pinned layer structure;
annealing the pinning layer while applying a magnetic field in a first direction to the first pinned layer, to set the magnetization direction of the first pinned layer in the first direction;
milling the upper surface of the first pinned layer after the setting of the magnetization direction of the first pinned layer;
smoothing the upper surface of the first pinned layer after milling the upper surface of the first pinned layer;
then depositing the remaining layers of the synthetic pinned layer structure;
depositing an electrically-conductive spacer layer;
depositing a free layer;
depositing an exchange bias layer;
annealing the exchange bias layer while applying a magnetic field in a second direction, different than the first direction, to the free layer, to set the magnetization direction of the free layer in the second direction; and
etching away a portion of the exchange bias layer to leave a pattern of exchange bias material and then depositing insulator material where the portion of the exchange bias layer was etched away.
42. A method as defined in claim 41 , wherein the annealing of the first pinned layer and the setting of the magnetization direction of the first pinned layer is performed in situ.
43. A method as defined in claim 41 , wherein the annealing of the first pinned layer and the setting of the magnetization direction of the first pinned layer is performed ex situ.