Self-aligned coil process in magnetic recording heads

A method of manufacturing a write head comprising:

• forming a P1 pedestal and a first back gap layer on top of a first pole P1 leaving a region between the first back gap layer and the first pole P1 layer for forming a coil, the first back gap layer formed at a distal end of the first pole P1;
• depositing a first insulation layer over at least a portion of the P1 pedestal, the first pole P1 and the first back gap layer and the region;
• depositing a coil photoresist layer on top of the first insulation layer;
• forming coil pockets in the coil photoresist layer;
• forming a coil by depositing copper in the coil pockets, wherein the coil has multiple turns;
• removing the coil photoresist layer to form spaces in between the coil turns;
• applying a second insulation layer to fill the spaces in between the coil turns;
• performing the step of hard baking the second insulation layer to encapsulate the coil;
• depositing alumina over the hard baked resist;
• performing a first chemical mechanical polishing (CMP) process;
• depositing a write gap on top of the coil, the second insulating layer, and the P1 pedestal and extending to an air bearing surface (ABS) at one end and over portions but not completely over a top surface of the first back gap layer at another end;
• forming a P2 pole tip on top of the write gap and at opposite end of the write gap, forming a second back gap on top of the first back gap;
• depositing alumina on the P2 pole tip and the second back gap layer;
• performing a second CMP process;
• forming a second coil layer;
• applying a third insulation layer on top of the second coil layer;
• and
• forming a P3 magnetic layer on top of the second coil layer extending from the P2 pole tip to the second back gap layer.