Low DC coil resistance planar writer
AssigneeHeadway Technologies, Inc.
InventorsCherng Chyi Han, Mao-Min Chen
Life of this patent
Estimating the term…
Abstract
Present processes used for planarizing a cavity filled with a coil and hard baked photoresist require that a significant amount of the thickness of the coils be removed. This increases the DC resistance of the coil. In the present invention, CMP is terminated as soon as the coils are exposed, allowing their full thickness to be retained and resulting in minimum DC resistance. Application of this process to the manufacture of a planar magnetic write head is described.
Claims29
A process to manufacture a planar magnetic write head, having an air bearing surface, comprising:
- providing a lower magnetic shield layer;
- forming a disc of dielectric material on said lower magnetic shield layer;
- forming, on said disc, a copper coil having at least 7 turns and a DC resistance that is less than about 5 ohms;
- depositing and then patterning a layer of ferromagnetic material to form a lower pole, having a top surface, that includes a centrally located trench on whose floor rest said dielectric disc and copper coil;
- depositing a layer of baked photoresist to a thickness that is sufficient to cover said coil and to extend at least 1 micron above the top surface of the lower pole;
- by means of chemical mechanical polishing, planarizing until said copper coil and said lower pole are just exposed;
- depositing, and then patterning, an insulating layer to form a lid that fully covers said coil and said trench;
- depositing a first layer of high permeability material and then patterning said first layer of high permeability material so that it contacts only said lower pole;
- depositing and then planarizing a throat height defining layer on said lid whereby said throat height defining layer has a surface that is coplanar with the top surface of the lower pole;
- then depositing and patterning a layer of non-magnetic material to selectively coat said first layer of high permeability material and said throat height defining layer while leaving said lower pole uncovered on a side that opposes said air bearing surface, thereby forming a write gap;
- depositing a second layer of high permeability material onto all exposed surfaces, and
- then forming a top pole on said second layer of high permeability material.
A planar magnetic write head, having an air bearing surface, comprising:
- a lower magnetic shield layer;
- a disc of dielectric material on said lower magnetic shield layer;
- on said lower magnetic shield layer, a lower magnetic pole that surrounds said disc;
- on said disc, a copper coil having at least 7 turns and a DC resistance that is less than about 5 ohms;
- a layer of baked photoresist that encapsulates said coil up as far as said coil's upper surface
- an insulating layer in the form of a lid that fully covers said coil and extends therefrom as far as said lower pole;
- a first layer of high permeability material on only said lower pole;
- a throat height defining layer on said lid, said throat height defining layer having a surface that is coplanar with the top surface of the lower pole;
- a layer of non-magnetic material on said throat height defining layer and on said lower pole, except on a side of the lower pole that opposes said air bearing surface, whereby it serves as a write gap;
- a second layer of high permeability material on said layer of non-magnetic material including said write gap, and on said side of the lower pole that opposes said air bearing surface;
- and
- a top pole on said second layer of high permeability material.
Dependencies are inferred from the claim text.