Apparatus having a hard bias seedlayer structure for providing improved properties of a hard bias layer
View Patent ↗An apparatus having improved hard bias properties of layers of a magnetoresistance sensor is disclosed. Properties of the hard bias layer are improved using a seedlayer structure that includes at least a layer of silicon and a layer comprising chromium or chromium molybdenum. Further, benefits are achieved when the seedlayer structure includes a layer of tantalum.
1. A magnetic storage system, comprising:
a moveable magnetic recording medium;
an actuator disposed proximate to the moveable magnetic recording medium; and
a read head, coupled to the actuator, for reading data on the moveable magnetic recording medium, the read head comprising
a spin valve structure including:
a ferromagnetic free layer structure that has a magnetic moment;
a ferromagnetic pinned layer structure having a magnetic moment;
a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure; and
an anti-ferromagnetic pinning layer coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
hard magnetic thin films disposed on both sides of the free layer structure; and
a hard bias seedlayer structure adjacent to at least a portion of the spin valve structure, wherein the hard bias seedlayer structure comprises at least a layer consisting of silicon and a layer comprising chromium or chromium molybdenum.
2. The magnetic storage system of claim 1 , wherein the anti-ferromagnetic pinning layer further comprises a layer of platinum manganese.
3. The magnetic storage system of claim 1 , wherein the hard bias seedlayer structure further comprises a layer of tantalum adjacent the silicon layer.
4. The magnetic storage system of claim 3 , wherein the layer of tantalum adjacent the silicon layer further comprises equal thickness of the tantalum and silicon layers.
5. The magnetic storage system of claim 3 , wherein the layer of tantalum adjacent the silicon layer further comprises a tantalum layer with a thickness half a thickness of the silicon layer.
6. The magnetic storage system of claim 3 , wherein the hard bias seedlayer structure further comprises a chromium alloy layer.
7. The magnetic storage system of claim 1 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium.
8. The magnetic storage system of claim 1 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium-molybendum.
9. A magnetic storage system, comprising:
a read head, coupled to the actuator, for reading data on the moveable magnetic recording medium, the read head comprising
a spin valve structure including:
a ferromagnetic free layer structure that has a magnetic moment;
a ferromagnetic pinned layer structure having a magnetic moment;
a nonmagnetic conductive spacer layer between the free layer structure and the pinned layer structure; and
an anti-ferromagnetic pinning layer coupled to the pinned layer structure for pinning the magnetic moment of the pinned layer structure;
hard magnetic thin films disposed on both sides of the free layer structure; and
a hard bias seedlayer structure adjacent to at least a portion of the spin valve structure, wherein the hard bias seedlayer structure comprises at least a layer consisting of silicon and a layer comprising chromium or chromium molybdenum.
10. The magnetic storage system of claim 9 , wherein the anti-ferromagnetic pinning layer further comprising a layer of platinum manganese.
11. The magnetic storage system of claim 9 , wherein the hard bias seedlayer structure further comprises a layer of tantalum adjacent the silicon layer.
12. The magnetic storage system of claim 11 , wherein the layer of tantalum adjacent the silicon layer further comprises equal thickness of the tantalum and silicon layers.
13. The magnetic storage system of claim 11 , wherein the layer of tantalum adjacent the silicon layer further comprises a tantalum layer with a thickness half a thickness of the silicon layer.
14. The magnetic storage system of claim 11 , wherein the hard bias seedlayer structure further comprises a chromium alloy layer.
15. The magnetic storage system of claim 9 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium.
16. The magnetic storage system of claim 9 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium-molybendum.
17. A spin valve sensor, comprising
a spin valve structure including a ferromagnetic free layer, a ferromagnetic pinned layer and an anti-ferromagnetic pinning layer;
hard magnetic thin films disposed on both sides of the spin valve structure; and
a hard bias seedlayer structure adjacent to at least a portion of the spin valve structure, wherein the hard bias seedlayer structure comprises at least a layer consisting of silicon and a layer comprising chromium or chromium molybdenum.
18. The spin valve sensor of claim 17 , wherein the pinning layer comprises platinum manganese.
19. The spin valve sensor of claim 17 , wherein the hard bias seedlayer structure further comprises a layer of tantalum adjacent the silicon layer.
20. The spin valve sensor of claim 19 wherein the layer of tantalum adjacent the silicon layer further comprises equal thicknesses of the tantalum and silicon layers.
21. The spin valve sensor of claim 19 , wherein the layer of tantalum adjacent the silicon layer further comprises a tantalum layer with a thickness half a thickness of the silicon layer.
22. The spin valve sensor of claim 19 , wherein the hard bias seedlayer structure further comprises a chromium alloy layer.
23. The spin valve sensor of claim 17 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium.
24. The spin valve sensor of claim 17 , wherein the hard bias seedlayer structure further comprises a layer of tantalum, silicon and chromium-molybendum.
25. A read sensor, comprises:
means for providing a spin valve structure, means for providing a spin valve structure further comprising:
means for providing a ferromagnetic free layer structure that has a magnetic moment;
means for providing a ferromagnetic pinned layer structure having a magnetic moment;
means for providing a nonmagnetic conductive spacer layer between the means for providing a ferromagnetic free layer structure and the means for providing a ferromagnetic pinned layer structure; and
means for providing an anti-ferromagnetic pinning layer coupled to the means for providing a pinned layer structure for pinning the magnetic moment of the pinned layer structure;
means for providing hard magnetic thin films adjacent to at least a portion of the means for providing a spin valve structure; and
means for providing a hard bias seedlayer structure adjacent the at least a portion of the means for providing a spin valve structure, wherein the means for providing a hard bias seedlayer structure comprises at least a layer consisting of silicon and a layer comprising chromium or chromium molybdenum.
26. A spin valve sensor, comprising
means for providing a spin valve structure including free means, pinned means and an pinning means;
means for providing hard magnetic thin films in an abutting relationship with the means for providing a spin valve structure on both sides of the means for providing a spin valve structure; and
means for providing a hard bias seedlayer structure adjacent the means for providing a spin valve structure, wherein means for providing the hard bias seedlayer structure comprises at least a layer consisting of silicon and a layer comprising chromium or chromium molybdenum.
27. A hard bias seedlayer structure adjacent a pinning layer structure, the seedlayer structure comprising at least a layer comprising silicon and a layer consisting of chromium or chromium molybdenum.
28. The seedlayer structure of claim 27 , wherein the seedlayer structure further comprises a layer of tantalum adjacent the silicon layer.