Write assist stack to reduce resistance and improve reliability
The present disclosure generally relates to a magnetic media drive employing a magnetic recording head. The magnetic recording head comprises a main pole, a hot seed layer, and a write assist stack disposed between the main pole and the hot seed layer. In one embodiment, the write assist stack comprises a seed layer, a spin torque layer, and a notch layer. One or more of the seed layer and the notch layer have a first cross-track width and the spin torque layer has a second cross-track width less than the first cross track width. In another embodiment, the write assist stack comprises a seed layer, a spin polarization layer, and a notch layer. One or more of the seed layer and the notch layer have a first cross-track width and the spin polarization layer has a second cross-track width less than the first cross track width.
1. A magnetic recording head, comprising:
a main pole;
a hot seed layer disposed above the main pole; and
a write assist stack disposed between and in contact with the main pole and the hot seed layer, the write assist stack comprising a notch layer having a first cross-track width, a seed layer disposed in contact with the main pole, and a first layer having a second cross-track width, wherein:
the first cross-track width is greater than the second cross-track width,
the first layer comprises a spin torque material or a non-magnetic, electrically conductive material, and
wherein the seed layer has a third cross-track width greater than the second cross-track width.
2. The magnetic recording head of claim 1 , wherein the notch layer is disposed adjacent to the hot seed layer, and wherein the first cross-track width is less than or equal to a cross-track width of the hot seed layer.
3. The magnetic recording head of claim 1 , wherein the second cross-track width is less than a cross-track width of a first surface of the main pole, the first surface of the main pole being adjacent to the write assist stack.
4. The magnetic recording head of claim 1 , wherein the first layer is a spin torque layer comprising the spin torque material, wherein the seed layer has the first cross-track width, and wherein the seed layer has a first stripe height greater than a second stripe height of the spin torque layer.
5. The magnetic recording head of claim 1 , wherein the first layer is a spin torque layer comprising the spin torque material, wherein the seed layer has the second cross-track width, and wherein the seed layer has a stripe height equal to a stripe height to the spin torque layer.
6. The magnetic recording head of claim 1 , wherein the write assist stack further comprises a spacer layer, the spacer layer having the first cross-track width.
7. The magnetic recording head of claim 1 , further comprising an electrically insulating layer disposed adjacent to the write assist stack between the hot seed layer and the main pole.
8. The magnetic recording head of claim 1 , wherein the first layer comprises the non-magnetic, electrically conductive material.
9. The magnetic recording head of claim 1 , wherein the write assist stack further comprises a cap layer, the cap layer having the first cross-track width.
10. The magnetic recording head of claim 1 , wherein the write assist stack further comprises a spin torque oscillator, the spin torque oscillator comprising the first layer and the notch layer, wherein the first layer is a spin torque layer comprising the spin torque material.
11. A data storage device comprising the magnetic recording head of claim 1 .
12. A magnetic recording head, comprising:
a main pole;
a hot seed layer disposed above the main pole; and
a write assist stack disposed between and in contact with the main pole and the hot seed layer, the write assist stack comprising a seed layer having a first cross-track width and a spin polarization layer having a second cross-track width, wherein the first cross-track width is greater than the second cross-track width.
13. The magnetic recording head of claim 12 , wherein the write assist stack further comprises a cap layer, the cap layer having the first cross-track width.
14. The magnetic recording head of claim 12 , wherein the write assist stack further comprises a notch layer disposed adjacent to the hot seed layer, the notch layer having the first cross-track width.
15. The magnetic recording head of claim 12 , wherein the write assist stack further comprises a notch layer disposed adjacent to the main pole, the notch layer having a third cross-track width less than or equal to a width of a first surface of the main pole, wherein the first surface of the main pole is adjacent to the write assist stack.
16. The magnetic recording head of claim 12 , wherein the second cross-track width is less than a cross-track width of a first surface of the main pole, the first surface of the main pole being adjacent to the write assist stack.
17. The magnetic recording head of claim 12 , wherein the write assist stack further comprises a field generation layer and a spacer layer, the spacer layer being disposed between the field generation layer and the spin polarization layer, wherein the field generation layer has the second cross-track width, and wherein each layer of the write assist stack as a same stripe height.
18. The magnetic recording head of claim 12 , wherein the write assist stack is a reverse write assist stack.
19. The magnetic recording head of claim 12 , wherein the write assist stack further comprises a spin torque oscillator, the spin torque oscillator comprising the spin polarizing layer and the seed layer.
20. A data storage device comprising the magnetic recording head of claim 12 .
21. A magnetic recording head, comprising:
a main pole;
a hot seed layer disposed above the main pole;
a write assist stack disposed at a media facing surface between and in contact with the main pole and the hot seed layer, the write assist stack comprising a seed layer having a first cross-track width and a spin polarization layer having a second cross-track width, wherein the first cross-track width is greater than the second cross-track width; and
an electrically insulating layer disposed adjacent to the write assist stack between the hot seed layer and the main pole, the electrically insulating layer comprising a non-conductive material, wherein the electrically insulating layer is recessed from the media facing surface.
22. The magnetic recording head of claim 21 , wherein the write assist stack further comprises a notch layer.
23. The magnetic recording head of claim 22 , wherein the notch layer has the first cross-track width, the notch layer being disposed adjacent to the hot seed layer, and wherein the seed layer has a first stripe height greater than a second stripe height of the spin polarization layer.
24. The magnetic recording head of claim 22 , wherein the notch layer has a third cross-track width, the third cross-track width being less than first cross-track width and greater than or equal to the second cross-track width, wherein the notch layer is disposed adjacent to the main pole.
25. The magnetic recording head of claim 21 , wherein the write assist stack further comprises a spin torque oscillator, the spin torque oscillator comprising the spin polarizing layer and the seed layer.
26. A data storage device comprising the magnetic recording head of claim 21 .