Integrable using amorphous magnetic material circuit inductor

• US 6,069,397 A
• Filed: 10/03/1997
• Issued: 05/30/2000
• Est. Priority Date: 05/03/1996
• Status: Expired due to Fees

• Current Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Original Assignee: Motorola, Inc. (Motorola Solutions, Inc.)
• Inventors: Howng, Wei-Yean, Shapiro, Gary H., Ramakrishnan, E. S., Cornett, Kenneth D.
• Primary Examiner(s): HARDY, DAVID B
• Application Number:
  US08/943,255
• Time in Patent Office: 970 Days
• Field of Search: 257/531, 257/528, 257/516, 257/379
• US Class Current: 257/531
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 2924/00 Indexing scheme for arrangements or methods for connecting or disconnecting semiconductor or solid-state bodies as covered by H01L24/00
• CPC Class Codes: H01L 2924/0002 Not covered by any one of groups H01L24/00, H01L24/00 and H01L2224/00

Abstract

An integrable circuit inductor (220) is formed from a patterned conductive material (110) that has a major portion completely encapsulated by a material (221, 223) that is substantially electrically non-conductive, and that has a magnetic response at the operating frequency of the inductor (220). Preferably, an amorphous ferrite material is used for encapsulation, which provides a closed magnetic flux path for the inductor (220) when processing a signal at its operating frequency.

Claims

1. An integrable circuit inductor comprising a patterned conductive material having a major portion completely encapsulated by an amorphous magnetic material that is substantially electrically non-conductive.

2. The integrable circuit inductor of claim 1, wherein the magnetic material comprises a ferrite material.

3. The integrable circuit inductor of claim 2, wherein the magnetic material comprises material selected from a group consisting of CuFe₂ O₄, BiFeO₃ --CuFe₂ O₄, and BiFeO₃ --ZnFe₂ O₄.

4. The integrable circuit inductor of claim 2, wherein:

the patterned conductive material comprises a planar conductor trace, with a particular conductor width, formed in a spiral pattern;

the magnetic material has two layers each having a thickness of between 0.5 and 5 times the particular conductor width; and

the planar conductor trace is sandwiched between the two layers of the magnetic material.

5. An integrated circuit inductor, comprising a substrate having a substantially amorphous magnetic material, and an inductance element having a major portion completely encompassed by the magnetic material.

6. The integrated circuit inductor of claim 5, wherein the substrate is formed from semiconductor material.

7. The integrated circuit inductor of claim 5, wherein the inductance element is embedded within, and is surrounded by the magnetic material.

8. The integrated circuit inductor of claim 5, wherein the inductance element is sandwiched between layers of the magnetic material.

9. The integrated circuit inductor of claim 5, wherein the magnetic material completely surrounds the inductance element.

10. The integrated circuit inductor of claim 5, wherein the magnetic material comprises amorphous ferrite material.

11. The integrated circuit inductor of claim 10, wherein the magnetic material comprises amorphous copper ferrite.

12. The integrated circuit inductor of claim 5, wherein the inductance element comprises a patterned conductive trace.

13. The integrated circuit inductor of claim 12, wherein the inductance element comprises a spiral conductor.

14. The integrated circuit inductor of claim 13, wherein the spiral conductor is planar.

15. An integrated circuit, comprising:

a substrate;

a first layer of amorphous magnetic material disposed on the substrate;

a second layer of amorphous magnetic material disposed over the first layer of amorphous magnetic material; and

a circuit element sandwiched between, and completely surrounded by the first and second layers of amorphous magnetic material.

16. The integrated circuit of claim 15, wherein the substrate is formed from semiconductor material.

17. The integrated circuit of claim 16, wherein the circuit element comprises an inductance element.

18. The integrated circuit of claim 17, wherein:

the inductance element is formed by a conductor trace patterned into a planar spiral; and

the first and second layers of amorphous magnetic material completely surround at least a major portion of the conductor trace.

21. The integrated circuit of claim 18, wherein the conductor trace has a particular line width, and the first and second layers of amorphous magnetic material each has a layer thickness of between 0.5 and 5 times the particular line width.

19. The integrated circuit of claim 19, wherein the first and second layers of amorphous magnetic material comprise ferrite material.

20. The integrated circuit of claim 19, wherein the ferrite material comprise material selected from a group consisting of CuFe₂ O₄, BiFeO₃ --CuFe₂ O₄, and BiFeO₃ --ZnFe₂ O₄.

22. An integrated circuit having an inductance element operable at an operating frequency, comprising:

a semiconductor substrate; and

amorphous magnetic material disposed on the semiconductor substrate;

wherein the inductance element is embedded within the magnetic material such that the amorphous magnetic material provides a closed magnetic flux path for the inductance element when processing a signal at the operating frequency.

23. The integrated circuit of claim 22, wherein the amorphous magnetic material comprises ferrite material.

24. The integrated circuit of claim 23, wherein the ferrite material comprises material selected from a group consisting of CuFe₂ O₄, BiFeO₃ --CuFe₂ O₄, and BiFeO₃ --ZnFe₂ O₄.

25. The integrated circuit of claim 23, wherein:

the inductance element comprises a spiral inductor formed from a conductor having a particular cross-sectional width along a particular plane; and

the conductor is sandwiched between first and second layers of the amorphous magnetic material each having a thickness of between one and five times the particular cross-sectional width measured perpendicular to the particular plane.