Method of forming a magnetic core on a substrate

1. A method of forming a magnetic core on a substrate having a stacked inductor coil, comprising:

etching a plurality of polymer layers to form at least one feature through the plurality of polymer layers, wherein the at least one feature is disposed within a central region of a stacked inductor coil formed on the substrate;

depositing a magnetic material within the at least one feature; and

at least one of:

wherein depositing the magnetic material comprises:

depositing a seed layer atop an uppermost polymer layer and in the at least one feature;

forming a second patterned masking layer atop the seed layer;

depositing the magnetic material within the at least one feature through the second patterned masking layer;

removing the second patterned masking layer; and

etching the seed layer, or

etching the plurality of polymer layers to form at least one additional feature through the plurality of polymer layers, wherein the at least one additional feature is a trench disposed around the stacked inductor coil or a plurality of vias disposed around the stacked inductor coil; and

depositing the magnetic material within the at least one additional feature.

2. The method of claim 1 , wherein etching the plurality of polymer layers comprises:

forming a first patterned masking layer atop the uppermost polymer layer of a plurality of polymer layers;

etching an exposed portion of the uppermost polymer layer through the first patterned masking layer to form the at least one feature through the plurality of polymer layers; and

removing the first patterned masking layer.

3. The method of claim 2 , wherein the exposed portion of the uppermost polymer layer is etched with a plasma-based dry etching process.

4. The method of claim 1 , wherein the seed layer comprises copper.

5. The method of claim 1 , wherein the at least one feature is a high aspect ratio via.

6. The method of claim 1 , wherein the magnetic material is deposited via a physical vapor deposition (PVD) process.

7. The method of claim 1 , wherein the magnetic material comprises one or more of iron (Fe), nickel (Ni), zinc (Zn), nickel-iron (NiFe), nickel-zinc (NiZn), nickel-zinc-copper (NiZnCu), aluminum-nickel-cobalt (AlNiCo), cobalt-tantalum-zirconium (CoTaZr), cobalt-niobium-zirconium (CoNbZr), cobalt-zirconium oxide (CoZrO 2 ), iron-hafnium nitride (FeHfN), or cobalt-iron-hafnium oxide (CoFeHfO).

8. The method of claim 1 , wherein the at least one feature includes a plurality of features.

9. The method of claim 1 , wherein the stacked inductor coil is a stacked spiral inductor coil, and further comprising:

forming the stacked spiral inductor coil atop the substrate, wherein the stacked spiral inductor coil is disposed within the plurality of polymer layers;

forming a first photoresist atop the uppermost polymer layer prior to etching the plurality of polymer lavers and depositing the seed layer;

etching a plurality of exposed portions of the uppermost polymer layer through the first photoresist to form one or more vias through the plurality of polymer layers, wherein the one or more vies are the at least one feature;

removing the first photoresist;

forming a second photoresist atop the seed layer, wherein the second photoresist is the second patterned masking layer;

depositing the magnetic material within the one or more vias through the second photoresist; and

removing the second photoresist.

10. The method of claim 9 , wherein each of the one or n ore vies has a high aspect ratio.

11. The method of claim 9 , wherein the magnetic material is deposited via a physical vapor deposition (PVD) process.

12. The method of claim 9 , wherein the magnetic material comprises one or more of iron (Fe), nickel (Ni), zinc (Zn), nickel-iron (NiFe), nickel-zinc (NiZn), nickel-zinc-copper (NiZnCu), aluminum-nickel-cobalt (AlNiCo), cobalt-tantalum-zirconium (CoTaZr), cobalt-niobium-zirconium (CoNbZr), cobalt-zirconium oxide (CoZrO 2 ), iron-hafnium nitride (FeHfN), or cobalt-iron-hafnium oxide (CoFeHfO).

13. The method of claim 9 , wherein the one or more vies is a plurality of vias.

14. The method of claim 9 , wherein the plurality of exposed portions of the uppermost polymer layer are etched with a plasma-based dry etching process.

15. The method of claim 9 , further comprising:

etching the plurality of polymer layers to form at least one additional feature through the plurality of polymer layers, wherein the at least one additional feature is a trench disposed around the stacked spiral inductor coil or a plurality of vias disposed around the stacked spiral inductor coil.

16. The method of claim 15 , further comprising depositing a magnetic material within the at least one additional feature.

17. The method of claim 9 , wherein the second photoresist is similar to the first photoresist.