Damascene write poles produced via full film plating
View Patent ↗A method for forming a write pole comprises forming a stop layer over a substrate layer of a wafer, the stop layer having an opening above a damascene trench in the substrate layer, and forming a buffer layer over the stop layer, the buffer layer having an opening above the opening of the stop layer. The method further comprises plating a layer of magnetic material over the wafer, disposing a first sacrificial material over a region of the magnetic material above the damascene trench, performing a milling or etching operation over the wafer to remove the magnetic material not covered by the first sacrificial material and to remove the first sacrificial material, disposing a second sacrificial material over the wafer, and performing a polishing operation over the wafer to remove the region of the magnetic material above the damascene trench, the second sacrificial material, and the buffer layer.
1. A method of forming a write pole, comprising the steps of:
forming a damascene trench in a substrate layer of a wafer;
forming a stop layer over the substrate layer of the wafer after the step of forming the damascene trench, the stop layer having an opening above the damascene trench in the substrate layer;
forming a buffer layer over the stop layer, the buffer layer having an opening above the opening of the stop layer;
plating a layer of magnetic material over the wafer after the stop layer and the buffer layer are formed;
disposing a first sacrificial material over a region of the magnetic material above the damascene trench;
performing a milling or etching operation over the wafer to remove the magnetic material not covered by the first sacrificial material and to remove the first sacrificial material;
disposing a second sacrificial material over the wafer; and
performing a polishing operation over the wafer to remove the region of the magnetic material above the damascene trench, to remove the second sacrificial material, and to remove the buffer layer.
2. The method according to claim 1 , further comprising the step of disposing a seed layer over the wafer before plating the magnetic material over the wafer.
3. The method according to claim 2 , wherein the step of performing the milling or etching operation further removes a portion of the seed layer not covered by the first sacrificial material.
4. The method according to claim 1 , wherein the step of performing a milling or etching operation comprises performing ion beam etching.
5. The method according to claim 1 , wherein the milling or etching operation is stopped before exposing the stop layer.
6. The method according to claim 1 , wherein the step of performing the polishing operation comprises performing chemical mechanical polishing (CMP).
7. The method according to claim 6 , wherein a CMP selectivity between the magnetic material and the stop layer is greater than 300:1.
8. The method according to claim 1 , wherein the stop layer comprises diamond-like carbon.
9. The method according to claim 1 , wherein the buffer layer comprises AlO x , where x is a positive integer.
10. The method according to claim 1 , wherein the magnetic material comprises CoNiFe, CoFe or NiFe.
11. The method according to claim 1 , wherein the first sacrificial material comprises photoresist.
12. The method according to claim 1 , wherein the second sacrificial material comprises alumina.
13. The method according to claim 1 , further comprising the step of forming the damascene trench in the substrate layer by:
forming a patterned mask layer over the substrate layer; and
etching a region of the substrate layer exposed by the patterned mask layer to form the damascene trench.
14. The method according to claim 13 , wherein the step of forming the damascene trench in the substrate layer further comprises:
disposing a layer of alumina over the wafer to adjust a width of the damascene trench.
15. The method according to claim 1 , wherein the substrate layer comprises alumina.
16. A method of forming a plurality of write poles, comprising the steps of:
forming a plurality of damascene trenches in a substrate layer of a wafer;
forming a stop layer over the substrate layer of the wafer after the step of forming the plurality of damascene trenches, the stop layer having a first plurality of openings above the plurality of damascene trenches in the substrate layer;
forming a buffer layer over the stop layer, the buffer layer having a second plurality of openings above corresponding ones of the first plurality of openings of the stop layer;
plating a layer of magnetic material over the wafer after the stop layer and the buffer layer are formed;
disposing a first sacrificial material over a plurality of regions of the magnetic material above corresponding ones of the plurality of damascene trenches;
performing a milling or etching operation over the wafer to remove the magnetic material not covered by the first sacrificial material and to remove the first sacrificial material;
disposing a second sacrificial material over the wafer; and
performing a polishing operation over the wafer to remove the plurality of regions of the magnetic material above the corresponding ones of the plurality of damascene trenches, to remove the second sacrificial material, and to remove the buffer layer.
17. The method according to claim 16 , further comprising the step of disposing a seed layer over the wafer before plating the magnetic material over the wafer.
18. The method according to claim 17 , wherein the step of performing the milling or etching operation further removes a portion of the seed layer not covered by the first sacrificial material.