Integrated circuit inductor with a magnetic core
View Patent ↗An inductor is fabricated on a substrate having a top surface and a bottom surface. The inductor includes a plurality of holes extending through the substrate, wherein the plurality of holes interconnect the top surface and the bottom surface of the substrate. The inductor also includes a plurality of conductive posts formed in the plurality of holes and a plurality of conductive segments formed on the top surface and on the bottom surface that interconnect the conductive posts such that a continuous conductive coil is formed. The inductor also includes a magnetic core that occupies substantially the entire volume enclosed by the conductive coil.
1. A computer system comprising:
a processor;
an inductor comprising:
a substrate;
a magnetic core formed within the substrate;
a plurality of vias filled with a metallic material providing a plurality of metallic posts through the substrate; and
a plurality of conductive segments interconnecting the plurality of conductive posts to form a conductive coil surrounding the magnetic core.
2. The system of claim 1 , wherein the plurality of vias comprises extend entirely through the substrate.
3. The system of claim 1 , wherein the plurality of vias comprises two substantially parallel rows of vias extending through the substrate.
4. The system of claim 1 , wherein the substrate comprises a semiconductor wafer.
5. The system of claim 1 , wherein the substrate comprises silicon.
6. The system of claim 1 , wherein the substrate comprises silicon carbide.
7. The system of claim 1 , wherein the substrate comprises germanium.
8. The system of claim 1 , wherein the magnetic core comprises a magnetic oxide.
9. The system of claim 1 , wherein forming the magnetic core comprises depositing ferromagnetic material by chemical vapor deposition.
10. The system of claim 1 , wherein the magnetic core comprises a porous region in the substrate.
11. The system of claim 10 , wherein the porous region is filled with a ferromagnetic material.
12. The system of claim 1 , wherein the conductive coil comprises copper.
13. The system of claim 1 , wherein the conductive coil comprises aluminum.
14. The system of claim 1 , wherein the substrate has at least two substantially parallel surfaces, and wherein the conductive posts are substantially perpendicular to the parallel surfaces.
15. The system of claim 1 , wherein the metallic posts have circular cross-sections.
16. The system of claim 1 , wherein the metallic posts are at least partially surrounded by an insulating material.
17. The system of claim 16 , wherein the insulating material comprises polyimide.
18. The system of claim 1 , wherein the inductor has an inductance of at least 1 nanohenry.
19. The system of claim 1 , further comprising a passivation layer covering the conductive coil.
20. The system of claim 19 , wherein the passivation layer is configured to electrically insulate the inductor and to protect the inductor from physical damage.
21. The system of claim 1 , wherein the inductor is part of a memory circuit in the computer system.
22. A computer memory device comprising:
a memory array on a substrate;
an inductor comprising:
a magnetic core formed within the substrate;
a plurality of vias filled with a metallic material providing a plurality of metallic posts through the substrate; and
a plurality of conductive segments interconnecting the plurality of conductive posts to form a conductive coil surrounding the magnetic core.
23. The memory device of claim 22 , wherein the substrate comprises a semiconductor wafer.
24. The memory device of claim 22 , wherein the substrate comprises silicon.
25. The memory device of claim 22 , wherein the conductive segments comprise a second metallic material.
26. The memory device of claim 22 , wherein the magnetic core comprises a porous region of the substrate treated with a ferromagnetic material.