Method of forming inductor with conductive trace

1. A method for forming an inductor, the method comprising:

forming an insulating layer on a first carrier;

forming a trench in the insulating layer, wherein:

an uppermost surface of the first carrier interfaces with the insulating layer, and

the uppermost surface of the first carrier defines a bottom of the trench;

forming a magnetic structure within the trench;

forming a conductive trace around the magnetic structure to form an inductor; and

electrically coupling the conductive trace to an active device having a top surface disposed under the insulating layer and a bottom surface disposed over the insulating layer.

2. The method of claim 1 , wherein the uppermost surface of the first carrier interfaces with the insulating layer at a first interface lying in a first plane and the bottom of the trench lies in the first plane.

3. The method of claim 1 , comprising:

forming an upper insulating layer on an upper insulating surface of the insulating layer and an upper magnetic surface of the magnetic structure; and

forming a lower insulating layer on a lower insulating surface of the insulating layer and a lower magnetic surface of the magnetic structure.

4. The method of claim 1 , comprising:

forming a first opening in the insulating layer concurrently with the forming a trench in the insulating layer;

forming a first filler structure by filling the first opening with a first filler material; and

forming a trench filler structure by filling the trench with a trench filler material different than the first filler material.

5. The method of claim 4 , the forming a conductive trace comprising:

removing the first filler structure from the first opening without removing the trench filler structure from the trench; and

forming a first conductive pillar by filling the first opening with a first conductive material, wherein the first conductive pillar is part of the conductive trace.

6. The method of claim 5 , the forming a magnetic structure comprising:

removing the trench filler structure from the trench without removing the first conductive pillar from the first opening; and

filling the trench with a magnetic material.

7. A method for forming an inductor, the method comprising:

forming a first opening, a second opening, a third opening, and a trench in an insulating layer, wherein the second opening exposes an uppermost surface of a first carrier interfacing with the insulating layer;

forming a first filler structure by filling the first opening with a first filler material;

forming a second filler structure by filling the second opening with a second filler material;

forming a third filler structure by filling the third opening with a third filler material;

forming a trench filler structure by filling the trench with a trench filler material, wherein the trench filler material is different than at least one of the first filler material, the second filler material, or the third filler material;

removing the first filler structure from the first opening, the second filler structure from the second opening, and the third filler structure from the third opening after the forming a trench filler structure;

forming a first conductive pillar by filling the first opening with a first conductive material;

forming a second conductive pillar by filling the second opening with a second conductive material;

forming a third conductive pillar by filling the third opening with a third conductive material;

removing the trench filler structure from the trench;

forming a magnetic structure by filling the trench with a magnetic material;

forming a first upper interconnect positioned above the magnetic structure and connecting the first conductive pillar and the second conductive pillar; and

forming a first lower interconnect positioned below the magnetic structure and connecting the second conductive pillar and the third conductive pillar, wherein the first conductive pillar, the first upper interconnect, the second conductive pillar, the first lower interconnect, and the third conductive pillar form a conductive trace around the magnetic structure to form an inductor.

8. The method of claim 7 , comprising, prior to the forming a first upper interconnect:

forming an upper insulating layer above the insulating layer, the first conductive pillar, the second conductive pillar, the third conductive pillar, and the magnetic structure.

9. The method of claim 8 , comprising:

forming a first upper insulating opening in the upper insulating layer to expose the first conductive pillar; and

forming a second upper insulating opening in the upper insulating layer to expose the second conductive pillar.

10. The method of claim 9 , wherein:

the forming a first conductive pillar comprises filling the first upper insulating opening with a first upper conductive material; and

the forming a second conductive pillar comprises filling the second upper insulating opening with a second upper conductive material.

11. The method of claim 10 , the forming a first upper interconnect comprising:

forming a layer of an upper conductive material over the first conductive pillar, the second conductive pillar, and the upper insulating layer; and

patterning the layer of the upper conductive material to establish the first upper interconnect between the first conductive pillar and the second conductive pillar.

12. The method of claim 7 , comprising, prior to the forming a first lower interconnect:

removing the first carrier; and

forming a lower insulating layer below the insulating layer, the first conductive pillar, the second conductive pillar, the third conductive pillar, and the magnetic structure.

13. The method of claim 12 , comprising:

forming a second lower insulating opening in the lower insulating layer to expose the second conductive pillar; and

forming a third lower insulating opening in the lower insulating layer to expose the third conductive pillar.

14. The method of claim 13 , wherein:

the forming a second conductive pillar comprises filling the second lower insulating opening with a second lower conductive material; and

the forming a third conductive pillar comprises filling the third lower insulating opening with a third lower conductive material.

15. The method of claim 14 , the forming a first lower interconnect comprising:

forming a layer of a lower conductive material below the second conductive pillar, the third conductive pillar, and the lower insulating layer; and

patterning the layer of the lower conductive material to establish the first lower interconnect between the second conductive pillar and the third conductive pillar.

16. A method for forming an inductor, the method comprising:

forming a first opening and a trench in an insulating layer to expose an uppermost surface of a first carrier through the first opening;

forming a first filler structure by filling the first opening with a first filler material;

forming a trench filler structure by filling the trench with a trench filler material;

removing the first filler structure from the first opening;

forming a first conductive pillar by filling the first opening with a first conductive material;

removing the trench filler structure from the trench;

forming a magnetic structure by filling the trench with a magnetic material, wherein a width of the magnetic structure is greater than or equal to a width of the first conductive pillar; and

forming a conductive trace around the magnetic structure to form an inductor, the conductive trace comprising the first conductive pillar.

17. The method of claim 16 , comprising:

forming an upper insulating layer above the insulating layer, the first conductive pillar, and the magnetic structure; and

forming a lower insulating layer below the insulating layer, the first conductive pillar, and the magnetic structure.

18. The method of claim 17 , comprising:

forming a first upper insulating opening in the upper insulating layer to expose the first conductive pillar; and

forming a first lower insulating opening in the lower insulating layer to expose the first conductive pillar.

19. The method of claim 18 , the forming a first conductive pillar comprising:

filling the first upper insulating opening with a first upper conductive material; and

filling the first lower insulating opening with a first lower conductive material.

20. The method of claim 2 , the forming a conductive trace comprising:

forming a first opening in the insulating layer, wherein a bottom of the first opening lies in the first plane.