Magnetic write pole having engineered radius of curvature and chisel angle profiles
View Patent ↗A magnetic transducer has air-bearing surface (ABS) and includes a main pole and at least one coil. The coil(s) energize the main pole. The main pole includes a yoke and a pole tip having an ABS-facing surface. The pole tip includes a sidewall having a radius of curvature and a chisel angle. The chisel angle is measured between a yoke direction perpendicular to the ABS and a tangent the sidewall. The chisel angle for the pole tip continuously increases in the yoke direction to a maximum a first distance from the ABS-facing surface in the yoke direction. The radius of curvature for the pole tip has a minimum radius of curvature a second distance from the ABS-facing surface in the yoke direction. The first distance is greater than the second distance.
1. A magnetic transducer having air-bearing surface (ABS) comprising:
a main pole including a yoke and a pole tip having an ABS-facing surface, the pole tip including a sidewall having a radius of curvature and a chisel angle measured between a yoke direction perpendicular to the ABS and a tangent the sidewall, the chisel angle for the pole tip continuously increasing in the yoke direction from a first chisel angle at the ABS-facing surface to a maximum a first distance from the ABS-facing surface in the yoke direction, the radius of curvature for the pole tip having a minimum radius of curvature a second distance from the ABS-facing surface in the yoke direction, the first distance being greater than the second distance; and
at least one coil for energizing the main pole.
2. The magnetic transducer of claim 1 wherein the pole tip extends not more than five hundred nanometers from the ABS-facing surface.
3. The magnetic transducer of claim 2 wherein the pole tip extends not more than four hundred and fifty nanometers from the ABS-facing surface.
4. The magnetic transducer of claim 2 wherein the pole tip extends not more than a third distance from the ABS-facing surface, the third distance being a location for which the chisel angle becomes constant.
5. The magnetic transducer of claim 1 wherein the chisel angle changes smoothly through at least the maximum.
6. The magnetic transducer of claim 1 wherein the radius of curvature changes smoothly at least through the minimum.
7. The magnetic transducer of claim 1 wherein the chisel angle is at least ten degrees and not more than thirty degrees at the ABS-facing surface.
8. The magnetic transducer of claim 7 wherein the chisel angle is at least fifteen degrees and not more than twenty-five degrees at the ABS-facing surface.
9. The magnetic transducer of claim 1 wherein the second distance of the minimum from the ABS-facing surface is at least zero nanometers and not more than eighty nanometers.
10. The magnetic transducer of claim 9 wherein the second distance is at least twenty nanometers.
11. The magnetic transducer of claim 9 wherein the second distance is at least forty and not more than sixty nanometers.
12. The magnetic transducer of claim 1 wherein the chisel angle decreases in the yoke direction from the maximum from the first distance to at least a third distance from the ABS-facing surface in the yoke direction and wherein the radius of curvature for the pole tip increases from the second distance to at least a fourth distance from the ABS-facing surface in the yoke direction.
13. The magnetic transducer of claim 12 wherein the chisel angle decreases to a constant value at the third distance.
14. The magnetic transducer of claim 1 further comprising:
a side gap; and
at least one side shield, the side gap being between the main pole and the at least one side shield.
15. A data storage device comprising:
a media;
a slider including a magnetic recording transducer having an air-bearing surface (ABS), a main pole and at least one coil for energizing the main pole, the main pole including a yoke and a pole tip having an ABS-facing surface, the pole tip including a sidewall having a radius of curvature and a chisel angle measured between a yoke direction perpendicular to the ABS and a tangent the sidewall, the chisel angle for the pole tip continuously increasing in the yoke direction from a first chisel angle at the ABS-facing surface to a maximum a first distance from the ABS-facing surface in the yoke direction, the radius of curvature for the pole tip being a minimum radius of curvature a second distance from the ABS-facing surface in the yoke direction, the first distance being greater than the second distance.
16. The data storage device of claim 15 wherein the chisel angle changes smoothly through at least the maximum, the chisel angle being at least fifteen and not more than twenty-five degrees at the ABS-facing surface;
wherein the radius of curvature changes smoothly at least through the minimum;
wherein the second distance of the minimum from the ABS-facing surface is at least zero nanometers and not more than eighty nanometers, the second distance being less than the first distance.
17. The data storage device of claim 16 wherein the chisel angle decreases in the yoke direction from the maximum from the first distance to at least a third distance from the ABS-facing surface in the yoke direction and wherein the radius of curvature for the pole tip increases from the second distance to at least a fourth distance from the ABS-facing surface in the yoke direction.
18. The data storage device of claim 17 wherein the chisel angle decreases to a constant value at the third distance.
19. A method for fabricating a magnetic transducer having an air-bearing surface (ABS) location, the method comprising:
providing a main pole including a yoke and a pole tip having an ABS-facing surface, the pole tip including a sidewall having a radius of curvature and a chisel angle measured between a yoke direction perpendicular to the ABS and a tangent the sidewall, the chisel angle for the pole tip continuously increasing in the yoke direction from a first chisel angle at the ABS-facing surface to a maximum a first distance from the ABS-facing surface in the yoke direction, the radius of curvature for the pole tip being a minimum radius of curvature at a second distance from the ABS-facing surface in the yoke direction, the first distance being greater than the second distance; and
providing at least one coil for energizing the main pole.
20. The method of claim 19 wherein the chisel angle changes smoothly through at least the maximum, the chisel angle being at least fifteen and not more than twenty-five degrees at the ABS-facing surface;
wherein the radius of curvature changes smoothly at least through the minimum;
wherein the second distance between the minimum and the ABS-facing surface is at least zero nanometers and not more than eighty nanometers, the second distance being less than the first distance.
21. The method of claim 20 wherein the chisel angle decreases in the yoke direction from the maximum from the first distance to at least a third distance from the ABS-facing surface in the yoke direction and wherein the radius of curvature for the pole tip increases from the second distance to at least a fourth distance from the ABS-facing surface in the yoke direction.
22. The method of claim 21 wherein the chisel angle decreases to a constant value at the third distance.
23. The method of claim 19 wherein the step of providing the main pole further includes:
depositing a photoresist layer corresponding to the main pole;
exposing the photoresist layer using a mask having a shape corresponding to the pole tip, the shape including a spacer therein, the second distance corresponding to a portion of the spacer;
removing a portion of the photoresist layer, a remaining portion of the photoresist layer forming a photoresist mask for the main pole.
24. The method of claim 23 further comprising:
depositing a hard mask layer on the photoresist mask;
removing the photoresist mask to form a hard mask for the main pole.