Inductor with magnetic material layers

• US 6,287,932 B2
• Filed: 02/20/2001
• Issued: 09/11/2001
• Est. Priority Date: 02/03/1999
• Status: Expired due to Term

• Current Assignee: Micron Technology, Inc.
• Original Assignee: Micron Technology, Inc.
• Inventors: Ahn, Kie Y., Forbes, Leonard
• Primary Examiner(s): Bowers, Charles
• Assistant Examiner(s): Huynh, Yennhu B.
• Application Number:
  US09/789,146
• Publication Number:
  US 20010005034A1
• Time in Patent Office: 203 Days
• Field of Search: 438/381, 438/385, 438/3, 438/238, 257/531
• US Class Current: 438/381
• CPC Class Codes: H01F 17/0013 with stacked layers
• 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
• CPC Class Codes: H01L 2924/3011 Impedance
• CPC Class Codes: Y10T 29/4902 Electromagnet, transformer or inductor
• CPC Class Codes: Y10T 29/4906 Providing winding
• CPC Class Codes: Y10T 29/49064 by coating
• CPC Class Codes: Y10T 29/49069 Data storage inductor or core
• CPC Class Codes: Y10T 29/49155 Manufacturing circuit on or in base

Abstract

A spiral inductor fabricated above a semiconductor substrate provides a large inductance while occupying only a small surface area. Including a layer of magnetic material above and below the inductor increases the inductance of the inductor. The magnetic material also acts as barrier that confines electronic noise generated in the spiral inductor to the area occupied by the spiral inductor. Inductance in a pair of stacked spiral inductors is increased by including a layer of magnetic material between the stacked spiral inductors.

Claims

1. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

depositing an inductor pattern on the insulating layer;

depositing a second insulating layer on the inductor pattern; and

depositing a second magnetic material layer on the second insulating layer.

2. The method of claim 1, wherein the substrate is a semiconductor.

3. The method of claim 1, wherein the magnetic material is a ferromagnetic.

4. The method of claim 1, wherein the insulating layer is silicon dioxide.

5. The method of claim 1, wherein the inductor pattern is a square spiral.

6. The method of claim 1, wherein the inductor pattern is a high-conductivity material.

7. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

depositing an inductor pattern on the insulating layer and above the magnetic material layer;

depositing a second insulating layer on the inductor pattern; and

depositing a second magnetic material layer on the second insulating layer.

8. The method of claim 7, wherein the substrate is a semiconductor.

9. The method of claim 7, wherein the magnetic material is a ferromagnetic.

10. The method of claim 7, wherein the insulating layer is silicon dioxide.

11. The method of claim 7, wherein the inductor pattern is a square spiral.

12. The method of claim 7, wherein the inductor pattern is a high-conductivity material.

13. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

depositing an inductor pattern on the insulating layer;

depositing a second insulating layer on the inductor pattern; and

depositing a second magnetic material layer on the second insulating layer above the inductor pattern.

14. The method of claim 13, wherein the substrate is a semiconductor.

15. The method of claim 13, wherein the magnetic material is a ferromagnetic.

16. The method of claim 13, wherein the insulating layer is silicon dioxide.

17. The method of claim 13, wherein the inductor pattern is a square spiral.

18. The method of claim 13, wherein the inductor pattern is a high-conductivity material.

19. A method of fabricating an inductor comprising:

selecting a silicon substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

depositing an inductor pattern on the insulating layer and above the magnetic material layer;

depositing a second insulating layer on the inductor pattern; and

depositing a second magnetic material layer on the second insulating layer and above the inductor pattern.

20. The method of claim 19, wherein the substrate is a semiconductor.

21. The method of claim 19, wherein the magnetic material is a ferromagnetic.

22. The method of claim 19, wherein the insulating layer is silicon dioxide.

23. The method of claim 19, wherein the inductor pattern is a square spiral.

24. The method of claim 19, wherein the inductor pattern is a high-conductivity material.

25. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

stacking a plurality of sandwich structures on the insulating layer, the method of fabricating the structures comprising;

depositing an inductor pattern on the insulating layer;

depositing an insulating layer on the inductor pattern;

depositing a layer of magnetic material on the insulating layer; and

depositing an insulating layer on the magnetic material layer;

fabricating a conducting path through the structures; and

connecting each inductor pattern serially to the inductor pattern above by the conducting path, such that a current flowing in the serially connected inductor patterns creates a reinforcing magnetic field in the magnetic material between adjacent inductor patterns.

26. The method of claim 25, wherein the substrate is a semiconductor.

27. The method of claim 25, wherein the magnetic material is a ferromagnetic.

28. The method of claim 25, wherein the insulating layer is silicon dioxide.

29. The method of claim 25, wherein the inductor pattern is a square spiral.

30. The method of claim 25, wherein the inductor pattern is a high-conductivity material.

31. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

stacking a plurality of sandwich structures on the insulating layer, the method of fabricating the structures comprising;

depositing an inductor pattern on the insulating layer and above the magnetic material layer;

depositing an insulating layer on the inductor pattern;

depositing a layer of magnetic material on the insulating layer; and

depositing an insulating layer on the magnetic material layer;

fabricating a conducting path through the structures; and

connecting each inductor pattern serially to the inductor pattern above by the conducting path, such that a current flowing in the serially connected inductor patterns creates a reinforcing magnetic field in the magnetic material between adjacent inductor patterns.

32. The method of claim 31, wherein the substrate is a semiconductor.

33. The method of claim 31, wherein the magnetic material is a ferromagnetic.

34. The method of claim 31, wherein the insulating layer is silicon dioxide.

35. The method of claim 31, wherein the inductor pattern is a square spiral.

36. The method of claim 31, wherein the inductor pattern is a high-conductivity material.

37. A method of fabricating an inductor comprising:

selecting a substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

stacking a plurality of sandwich structures on the insulating layer, the method of fabricating the structures comprising;

depositing an inductor pattern on the insulating layer;

depositing an insulating layer on the inductor pattern;

depositing a layer of magnetic material on the insulating layer and above the inductor pattern; and

depositing an insulating layer on the magnetic material layer;

fabricating a conducting path through the structures; and

connecting each inductor pattern serially to the inductor pattern above by the conducting path, such that a current flowing in the serially connected inductor patterns creates a reinforcing magnetic field in the magnetic material between adjacent inductor patterns.

38. The method of claim 37, wherein the substrate is a semiconductor.

39. The method of claim 37, wherein the magnetic material is a ferromagnetic.

40. The method of claim 37, wherein the insulating layer is silicon dioxide.

41. The method of claim 37, wherein the inductor pattern is a square spiral.

42. The method of claim 37, wherein the inductor pattern is a high-conductivity material.

43. A method of fabricating an inductor comprising:

selecting a silicon substrate;

depositing a layer of magnetic material on the substrate;

depositing an insulating layer on the magnetic material layer;

stacking a plurality of sandwich structures on the insulating layer, the method of fabricating the structures comprising;

depositing an inductor pattern on the insulating layer and above the magnetic material layer;

depositing an insulating layer on the inductor pattern;

depositing a layer of magnetic material on the insulating layer and above the inductor pattern; and

depositing an insulating layer on the magnetic material layer;

fabricating a conducting path through the structures; and

connecting each inductor pattern serially to the inductor pattern above by the conducting path, such that a current flowing in the serially connected inductor patterns creates a reinforcing magnetic field in the magnetic material between adjacent inductor patterns.

44. The method of claim 43, wherein the substrate is a semiconductor.

45. The method of claim 43, wherein the magnetic material is a ferromagnetic.

46. The method of claim 43, wherein the insulating layer is silicon dioxide.

47. The method of claim 43, wherein the inductor pattern is a square spiral.

48. The method of claim 43, wherein the inductor pattern is a high-conductivity material.