Short yoke length coils for magnetic heads in disk drives
View Patent ↗A method of forming a single layer inductive coil structure includes forming a first conductive coil on a substrate, forming an insulating layer by atomic layer deposition (ALD) over the first coil and the substrate, and forming one or more additional conductive coils on each of adjacent sides of the first coil insulated from the first coil and the substrate by the insulating layer. A method of forming a stacked layer inductive coil includes forming a cavity in a substrate, forming a first coil in the cavity wherein the cavity has an atomic layer deposition (ALD) layer, forming a second coil in the cavity adjacent to the first coil and separated by the ALD layer from the first coil, forming an insulating layer over the first and second coil, and forming a third coil on the insulating layer.
1. A method of forming a multi-turn coil comprising:
forming a first conductive coil on a substrate arranged with an electrical interconnect pattern;
forming an insulating atomic layer deposition (ALD) layer on the first coil;
after forming the ALD layer, forming one or more additional conductive coils on each of adjacent sides of the first coil insulated from the first coil and the substrate by the insulating layer;
planarizing the ALD to expose the first and the one or more additional conductive coils;
forming an insulating cap on the exposed first and the one or more additional conductive coils; and
forming a layer of magnetic material over the ALD coated and capped first and the one or more additional conductive coils.
2. The method of claim 1 , wherein the forming the first conductive coil further comprises:
forming a seed layer of a conductive material on the substrate;
forming a photolithographic mask to expose portions of the seed layer; and
plating a conductive material on the exposed seed layer to form a precursor coil and additional sacrificial conductive material.
3. The method of claim 2 , wherein the forming of the insulating atomic layer deposition (ALD) layer on the first coil comprises depositing an atomic layer deposition (ALD) insulating material to encapsulate and insulate the precursor coil and additional sacrificial conductive material from each other.
4. The method of claim 3 , wherein the insulating material is at least one of alumina, silicon oxide, silicon nitride and aluminum nitride.
5. The method of claim 3 , wherein the planarizing of the ALD comprises removing by chemical mechanical polishing (CMP) an amount of the atomic layer deposition (ALD) insulating material to expose the additional sacrificial conductive material.
6. The method of claim 5 , wherein forming the insulating cap comprises forming an insulating material cap layer by ALD to mask the first and the one or more additional conductive coils and the deposited ALD layer, thereby insulating the first and the one or more additional conductive coils and additional sacrificial conductive material.
7. The method of claim 6 , further comprising removing the additional sacrificial conductive material.
8. The method of claim 7 , further comprising depositing magnetic material to encapsulate the first and the one or more additional conductive coils.
9. The method of claim 8 , further comprising:
depositing an insulating filler material over at least a portion of the encapsulating magnetic material; and
planarizing the encapsulated magnetic material and filler material.
10. The method of claim 9 , further comprising depositing a stiffening material over at least a portion of the planarized encapsulated magnetic material and filler material, wherein the stiffening material has a Young's modulus greater than the encapsulated magnetic material and filler material.
11. The method of claim 10 , further comprising removing a portion of encapsulated magnetic material and substrate to form an air bearing surface.