Additive write pole process for wrap around shield
View Patent ↗A method for manufacturing a magnetic write head having a wrap around magnetic trailing shield and a very narrow track width. A magnetic write pole is formed by forming a mask over a magnetic write pole material and performing a first ion milling to define the write pole. The mask includes a hard mask layer such as diamond like carbon (DLC) and further mask layers formed over the hard mask layer. In order to facilitate manufacture at very narrow track widths processes are employed to remove re-deposited material and the remaining portions of the mask structure (except the hard mask). Further processing can then be employed without the risk of a very narrow mask structure and redep bending or breaking during later manufacturing steps.
1. A method for manufacturing a magnetic write head comprising:
providing a substrate;
depositing a magnetic write pole material over the substrate;
depositing mask structure over the write pole material the mask including a hard mask contacting the magnetic write pole material and additional mask layers formed over the hard mask;
performing a first ion milling to remove portions of the magnetic write pole material that are not protected by the mask structure to form a magnetic write pole having first and second sides;
after performing the first ion milling, removing the additional mask layers, leaving the hard mask intact;
after removing the portion of the hard mask structure formed over the hard mask, depositing a non-magnetic side gap material;
after depositing the non-magnetic side gap material, performing a second ion milling sufficiently to form the non-magnetic side gap material into first and second non-magnetic sides walls, formed at the first and second sides of the write pole, each of the first and second non-magnetic side walls having an outer edge opposite the write pole, the second ion milling being performed sufficiently to form a recess in the substrate, the recess initiating at the outer edge of each of the first and second non-magnetic side gaps;
depositing a fill layer;
performing a chemical mechanical polishing sufficiently to expose the hard mask;
removing the fill layer;
performing a reactive ion etching to remove the hard mask
depositing a non-magnetic, electrically conductive seed layer; and
electroplating a magnetic material over the non-magnetic, electrically conductive seed layer to form a trailing, wrap-around magnetic shield.
2. A method as in claim 1 wherein the depositing a non-magnetic side gap layer comprises depositing alumina by atomic layer deposition.
3. A method as in claim 1 wherein the depositing a non-magnetic side gap layer comprises depositing alumina by chemical vapor deposition.
4. A method as in claim 1 wherein the fill layer comprises SiO 2 or SiON.
5. A method as in claim 1 , wherein the first ion milling results in re-deposited material being formed on the sides of the mask structure, the method further comprising, after performing the first ion milling and before removing the portion of the mask structure formed over the hard mask, performing a KOH wet etch.
6. A method as in claim 1 wherein the removing the portion of the mask structure formed over the hard mask comprises using a hot n-methyl-pyrrolidone (NMP).
7. A method as in claim 1 wherein the fill layer comprises SiO 2 deposited by ion beam deposition.
8. A method for manufacturing a magnetic write head comprising:
providing a substrate;
depositing a magnetic write pole material over the substrate;
depositing mask structure over the write pole material the mask including a hard mask contacting the magnetic write pole material and additional mask layers formed over the hard mask;
performing a first ion milling to remove portions of the magnetic write pole material that are not protected by the mask structure to form a write pole having first and second sides;
after performing the first ion milling, removing the additional mask layers, leaving the hard mask intact;
depositing a non-magnetic side gap material;
after depositing the non-magnetic side gap material, performing a second ion milling sufficiently to expose the hard mask, and sufficiently to form the non-magnetic side gap material into first and second side walls formed at the first and second sides of the write pole, the non-magnetic side walls each having an outer edge opposite the write pole, the second ion milling being performed sufficiently to form a recess in the substrate, the recess initiating at the outer edge of each of the first and second side walls;
performing a reactive ion etching to remove the hard mask;
depositing an electrically conductive, non-magnetic seed layer; and
electroplating a magnetic material to form a trailing magnetic shield.
9. A method as in claim 8 wherein the second ion milling is an Ar ion milling.
10. A method as in claim 8 wherein the removing a portion of the mask layer comprises performing a hot n-methyl-pyrrolidone (NMP).
11. A method as in claim 8 wherein the first ion milling results in redeposited material being deposited onto the mask structure, the method further comprising, after performing the first ion milling, removing the redeposited material.
12. A method as in claim 8 further comprising after performing the first ion milling, performing a KOH wet etch.
13. A method as in claim 8 further wherein the depositing a non-magnetic side gap material comprises depositing alumina.
14. A method as in claim 8 further wherein the depositing a non-magnetic side gap material comprises depositing alumina by atomic layer deposition.
15. A method as in claim 8 further comprising employing an end point detection method to determine when the second ion milling has reached the hard mask layer, and terminating the second ion milling when the hard mask layer has been reached.
16. A method as in claim 8 further comprising employing a secondary ion mass spectroscopy to determine when the second ion milling has reached the hard mask layer, and terminating the second ion milling when the hard mask layer has been reached.