Integrated circuit inductors

• US 20020095774A1
• Filed: 03/19/2002
• Published: 07/25/2002
• Est. Priority Date: 07/09/1999
• Status: Active Grant

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ahn, Kie Y., Forbes, Leonard
• Granted Patent: US 6,779,250 B2
• Time in Patent Office: Days
• US Class Current: 29/604
• CPC Class Codes: H01F 17/0033 with the coil helically wound around a magnetic core
• CPC Class Codes: H01F 27/2804 Printed windings
• CPC Class Codes: H01F 37/00 Fixed inductances not covered by group H01F17/00
• CPC Class Codes: H01L 27/08 including only semiconductor components of a single kind
• CPC Class Codes: Y10S 257/924 with passive device, e.g. capacitor, or battery, as integral part of housing or housing element, e.g. cap
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/49037 Using reference point/surface to facilitate measuring
• CPC Class Codes: Y10T 29/49069 Data storage inductor or core
• CPC Class Codes: Y10T 29/49071 by winding or coiling
• CPC Class Codes: Y10T 29/49073 by assembling coil and core
• CPC Class Codes: Y10T 29/49075 including permanent magnet or core

Abstract

The invention relates to an inductor comprising a plurality of interconnected conductive segments interwoven with a substrate. The inductance of the inductor is increased through the use of coatings and films of ferromagnetic materials such as magnetic metals, alloys, and oxides. The inductor is compatible with integrated circuit manufacturing techniques and eliminates the need in many systems and circuits for large off chip inductors. A sense and measurement coil, which is fabricated on the same substrate as the inductor, provides the capability to measure the magnetic field or flux produced by the inductor. This on chip measurement capability supplies information that permits circuit engineers to design and fabricate on chip inductors to very tight tolerances.

Claims

1. A method comprising:

boring a plurality of holes in a substratum; and

fabricating a conductive path linking the plurality of holes.

2. The method of claim 1, wherein boring a plurality of holes in the substratum comprises:

positioning a drill on the substratum; and

drilling a hole in the substratum.

3. The method of claim 1, wherein boring a plurality of holes in the substratum comprises:

aiming a laser at the substratum; and

burning a hole in the substratum.

7. The method of claim 1, wherein fabricating the conductive path includes passing a conductor through the plurality of holes.

8. The method of claim 7, wherein the conductive path forms a coil surrounding a portion of the substratum.

9. The method of claim 1, including;

forming a magnetic film atop the substratum; and

traversing the magnetic film with a portion of the conductive path.

4. A method comprising;

boring a number of substantially parallel holes in a substrate having a coating;

depositing a conductive path linking the number of holes and operable for inducing a magnetic flux in the coating.

5. The method of claim 4, wherein depositing a conductive path comprises:

filling the holes with a conductive material; and

connecting the holes with a conductive material.

10. The method of claim 4, including:

filling the holes with a first conductive material; and

connecting the first conductive material with segments of a second conductive material.

11. The method of claim 4, wherein the first conductive material is aluminum or copper.

12. The method of claim 4, including forming the segments of the second conductive material so that a number of the segments of the second conductive material traverse the coating.

13. The method of claim 4, including forming the coating from a magnetic film.

14. The method of claim 13, including forming an insulating layer over the magnetic film.

16. The method of claim 15, including forming the coating as a magnetic film.

17. The method of claim 16, including forming an insulating layer over the magnetic film and over the number of conductive segments.

19. The method of claim 18, including forming the first conductive segments and the second conductive segments of a single metal.

20. The method of claim 18, wherein a portion of the second conductive segments are planar and traverse the magnetic film.

21. The method of claim 18, wherein boring the plurality of through holes includes irradiating the substrate with a laser.

22. The method of claim 18, wherein boring the plurality of through holes includes drilling the holes in the substrate with a drill bit.

24. The method of claim 23, wherein the coil has an inductance, and further comprising:

forming a magnetic film on one of the surfaces of the substrate; and

traversing the magnetic film with a portion of the coil so as to increase the inductance of the coil.

25. The method of claim 24, further including forming an insulator layer over the magnetic film and the portion of the coil traversing the magnetic film.

26. The method of claim 23, wherein forming the plurality of holes includes drilling the holes with a laser.

27. The method of claim 23, wherein forming the plurality of holes includes drilling the holes with a drill bit.

28. The method of claim 23, wherein forming the plurality of holes includes etching the substrate with a dry etch process.

30. The method of claim 29, wherein forming the coating includes depositing a magnetic film.

6. A method comprising:

drilling a plurality of holes in a substrate;

filling the plurality of holes with a conductive material to form a plurality of conductive segments; and

interconnecting the plurality of conductive segments to form a coil.

15. The method of claim 6, further including:

coating a portion of the substrate; and

traversing the coating with a number of the plurality of conductive segments.

18. A method of forming an inductor, comprising:

coating a portion of a surface of a substrate with a magnetic film;

boring a plurality of through holes adjacent the magnetic film that pass through the substrate; and

forming a conductive path integral with the substrate by forming first conductive segments in the through holes and forming second conductive segments that connect to the first conductive segments to form a coil.

23. A method of forming an inductor integral with a semiconductor substrate, comprising:

forming a plurality of holes in the semiconductor substrate that connect opposing surfaces of the substrate; and

interweaving a conductor through the plurality of holes to form a coil surrounding a portion of the substrate.

29. A method of forming an inductor comprising:

forming a coating on a portion of a surface of a substrate;

forming a plurality of holes through the substrate adjacent opposing edges of the coating; and

forming a conductive coil that passes through the plurality of holes and is operable to induce a magnetic flux in the coating.

31. A method of forming an inductor, comprising;

boring a plurality of holes in a semiconductor substrate; and

forming a conductive coil integral with the substrate, the conductive coil having segments passing through the plurality of holes.

32. The method of claim 31, including boring the plurality of holes so as to form a conductive coil having a triangular cross-section.

33. The method of claim 31, including forming the plurality of holes so as to form a conductive coil having a rectangular cross-section.

34. The method of claim 31, wherein boring the plurality of holes includes irradiating the substrate with a laser.

35. The method of claim 31, wherein boring the plurality of holes includes drilling the substrate with a drill bit.

36. The method of claim 31, wherein boring the plurality of holes includes etching the substrate with a dry etchant.