Integrated circuit with inductor having horizontal magnetic flux lines

• US 20070254448A1
• Filed: 06/11/2007
• Published: 11/01/2007
• Est. Priority Date: 07/02/2003
• Status: Active Grant

• Current Assignee: Bell Semiconductor, LLC (Hilco Inc. (d/b/a Hilco Global))
• Original Assignee: LSI Logic Corporation (Broadcom, Inc.)
• Inventors: Bhatt, Hemanshu, Allman, Derryl, Fure, Jan
• Granted Patent: US 7,384,801 B2
• Time in Patent Office: Days
• US Class Current: 438/381
• CPC Class Codes: H01L 23/5227 Inductive arrangements or effects of, or between, wiring layers other inductive arrangements H01L23/645
• CPC Class Codes: H01L 28/10 Inductors
• 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 integrated circuit (IC) includes one or more inductors that have magnetic flux lines substantially parallel to a generally horizontal plane of the IC. The inductor is formed in a plurality of conductor layers separated by insulating layers of the IC. Regions of highest magnetic flux density of the inductor may preferably be located near the edge of the IC. Additionally, the inductor may preferably be segmented. The over-all inductance may preferably be controlled by turning on and off selected inductors or inductor segments.

Claims

1. A method of fabricating an integrated circuit having conductor layers separated by insulating layers arranged substantially parallel to a plane of the integrated circuit, comprising:

forming an inductor within the conductor layers and the insulating layers and having magnetic flux lines substantially parallel to the plane of the integrated circuit upon operation of the integrated circuit.

2. A method as defined in claim 1 wherein:

the step of forming the inductor further comprises;

forming the inductor in a substantially coil-shaped configuration.

3. A method as defined in claim 1 wherein:

the step of forming the inductor further comprises;

forming a first segment of the inductor;

forming a second segment of the inductor proximate to and spaced apart from the first segment; and

electrically connecting the first segment and the second segment.

4. A method as defined in claim 3 wherein:

the step of forming the first segment further comprises;

forming the first segment of the inductor having a coil-shape in a first spiraling angular direction; and

the step of forming the second segment further comprises;

forming the second segment of the inductor having a coil-shape in a second spiraling angular direction.

5. A method as defined in claim 3 wherein:

the step of forming the first segment further comprises;

forming the first segment of the inductor having a magnetic flux field in a predetermined orientation upon operation of the integrated circuit; and

the step of forming the second segment further comprises;

forming the second segment of the inductor having a magnetic flux field in the predetermined orientation upon operation of the integrated circuit.

6. A method as defined in claim 3 wherein the integrated circuit includes other components for performing functions of the integrated circuit, further comprising:

forming conductors between the first segment and the second segment, the conductors electrically connecting the other components of the integrated circuit.

7. A method as defined in claim 3 wherein:

the step of electrically connecting the first segment and the second segment further comprises;

forming an electrical conductor in only one of the conductor layers between the first segment and the second segment.

8. A method as defined in claim 1 wherein:

the step of forming the inductor further comprises;

forming a plurality of segments of the inductor; and

electrically connecting the segments.

9. A method as defined in claim 1 wherein:

the inductor includes an end;

the integrated circuit includes an edge; and

the step of forming the inductor further comprises;

forming the inductor with the end thereof proximate to the edge of the integrated circuit.

10. A method as defined in claim 9 wherein:

the aforementioned edge of the integrated circuit is a first edge;

the integrated circuit includes a second edge opposite the first edge;

the aforementioned end of the inductor is a first end;

the inductor includes a second end opposite the first end; and

the step of forming the inductor further comprises;

forming the inductor with the first end thereof proximate to the first edge of the integrated circuit and the second end of the inductor proximate to the second edge of the integrated circuit.

11. A method as defined in claim 9 wherein:

the magnetic flux lines of the inductor have a greatest density at the end of the inductor proximate to the edge of the integrated circuit upon operation of the integrated circuit.

12. A method as defined in claim 1 wherein the inductor has a substantially rectangular cross section and includes horizontal legs and vertical legs, further comprising:

forming the horizontal legs within the conductor layers; and

forming the vertical legs within the conductor layers and the insulating layers.

13. A method as defined in claim 1 wherein the aforementioned inductor is a first inductor, further comprising:

forming a second inductor within the conductor layers and the insulating layers and having magnetic flux lines substantially parallel to the plane of the integrated circuit upon operation of the integrated circuit, the second inductor being substantially similar to the first inductor and offset laterally and longitudinally from the first inductor.

14. A method as defined in claim 1 wherein the aforementioned inductor is a first inductor, further comprising:

forming a plurality of inductors similar to the first inductor, each of the inductors having an inductance;

electrically connecting the inductors in a series in which each inductor, except a last inductor in the series, is followed by at least one inductor subsequent thereto and each inductor, except an initial inductor in the series, is preceded by at least one inductor;

electrically connecting the inductors with a plurality of switch devices, each switch device corresponding to at least one of the inductors, each switch device turning off the corresponding inductor and any inductors subsequent to the corresponding inductor when the switch device is in a first state, each switch device turning on the corresponding inductor when the switch device and the switch devices corresponding to any inductors preceding the corresponding inductor are in a second state, each of the inductors adding to an over-all inductance of the plurality of inductors when turned on;

selecting the over-all inductance of the plurality of inductors by selecting at least a portion of the inductors; and

setting the over-all inductance of the plurality of inductors by having in the first state at least one switch device for which the corresponding inductor and any subsequent inductors thereof are not selected.

15. A method as defined in claim 1 wherein the aforementioned inductor is a first inductor, further comprising:

forming a plurality of inductors similar to the first inductor, each of the inductors having an inductance;

electrically connecting the inductors with a plurality of switch devices, each switch device corresponding to one of the inductors and turning off the corresponding inductor when in a first state and turning on the corresponding inductor when in a second state, each of the inductors adding to an over-all inductance of the plurality of inductors when turned on;

selecting the over-all inductance of the plurality of inductors by selecting at least a portion of the inductors; and

setting the over-all inductance of the plurality of inductors by having in the first state any switch devices that correspond to any inductors that are not selected and having in the second state any switch devices that correspond to any inductors that are selected.