High Q compact inductors for monolithic integrated circuit applications

• US 5,805,043 A
• Filed: 10/02/1996
• Issued: 09/08/1998
• Est. Priority Date: 10/02/1996
• Status: Expired due to Term

• Current Assignee: Cobham Defense Electronic Systems Corporation (Cobham PLC)
• Original Assignee: ITT Industries (ITT, Inc.)
• Inventors: Bahl, Inder J.
• Primary Examiner(s): Gellner, Michael L.
• Assistant Examiner(s): MAI, ANH T
• Application Number:
  US08/720,672
• Time in Patent Office: 706 Days
• Field of Search: 336/200, 336/232, 336/223
• US Class Current: 336/200
• 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

Abstract

A monolithic inductor device is disclosed which typically includes a substrate. The improvement includes a layer of dielectric material disposed over the substrate. A first inductor pattern disposed on the substrate and a second inductor pattern disposed on the dielectric layer. The inductor patterns are coupled together to form a single inductive element, which has reduced dissipation losses and an improved frequency response due to the dielectric material.

Claims

1. A monolithic inductor device which including a substrate having a dielectric constant of 12.9, wherein the improvement therewith comprising:

a layer of dielectric material comprising a cured, dehydrated polyamide film having a dielectric constant of 3.0 and a thickness of 10 um disposed over said substrate;

a first inductor pattern disposed directly onto said substrate, wherein said first inductor pattern is disposed between said substrate and said dielectric material;

a second inductor pattern disposed on said dielectric layer,

means for coupling said first inductor pattern with said second inductor pattern so as to form a single inductive element extending through said dielectric material having said dielectric constant less than the dielectric constant of said substrate to reduce dissipation losses and improve the frequency response of the device.

2. The device of claim 1, which further includes a second layer of dielectric material disposed between said substrate and said layer of dielectric material.

3. The device of claim 2, wherein said second layer of dielectric material comprises a cured, dehydrated polymide film having a dielectric constant of 12.9.

4. The device of claim 1, wherein said means for coupling said first inductor pattern with said second inductor pattern is a via hole contained within said layer of dielectric material.

5. The device of claim 1, wherein said coupling means is operable to permit RF current to flow in the same direction in both said inductor patterns thereby increasing the inductance of said device.

6. The device of claim 1, wherein said first and second inductor patterns are gold conductors.

7. The device of claim 6, wherein said gold conductors have a thickness of 10 um.

8. The device of claim 1, wherein said substrate is a Gallium Arsenide (GaAs) material having a thickness of between 75 um and 125 um.

9. A monolithic inductor device, comprising:

a substrate having a dielectric constant of 12.9,

a layer of dielectric material comprising a cured, dehydrated polyamide film having a dielectric constant of 3.0 disposed over said substrate;

a first inductor pattern disposed directly onto said substrate wherein said first inductor pattern is disposed between said substrate and said dielectric material;

a second inductor pattern disposed on said dielectric layer,

means for coupling said first inductor pattern with said second inductor pattern so as to form a single inductive element extending through said dielectric material having said dielectric constant less than the dielectric constant of said substrate to reduce dissipation losses and improve the frequency response of the device.

10. The device of claim 9, which further includes a second layer of dielectric material disposed between said substrate and said layer of dielectric material.

11. The device of claim 10, wherein said second layer of dielectric material comprises a cured, dehydrated polymide film having a dielectric constant of 12.9.

12. The device of claim 9, wherein said means for coupling said first inductor pattern with said second inductor pattern is a via hole contained within said layer of dielectric material.

13. The device of claim 9, wherein said coupling means is operable to permit RF current to flow in the same direction in both said inductor patterns thereby increasing the inductance of said device.

14. The device of claim 9, wherein said first and second inductor patterns are gold conductors.

15. The device of claim 14, wherein said gold conductors have a thickness of 10 um.

16. The device of claim 9, wherein said substrate is a Gallium Arsenide (GaAs) material having a thickness of between 75 um and 125 um, and wherein said layer of dielectric material has a thickness of 10 um.