Multi-level RF passive device

• US 7,053,460 B2
• Filed: 12/21/2001
• Issued: 05/30/2006
• Est. Priority Date: 12/21/2001
• Status: Expired due to Term

• Current Assignee: Twitter Inc (X Holdings Corp.)
• Original Assignee: International Business Machines Corporation
• Inventors: Stein, Kenneth J., Petrarca, Kevin S., Volant, Richard P., Groves, Robert A., Malinowski, John C., Subbanna, Seshadri
• Primary Examiner(s): VU, HUNG K
• Application Number:
  US10/026,146
• Publication Number:
  US 20030116850A1
• Time in Patent Office: 1,621 Days
• Field of Search: 257/211, 257/528, 257/531, 257/751, 257/752, 257/758, 257/759, 257/762, 257/774, 438/128, 438/129, 438/329, 438/381, 438/626, 438/627, 438/631, 438/685, 438/687, 438/618
• US Class Current: 257/531
• CPC Class Codes: H01L 23/5283 Cross-sectional geometry
• CPC Class Codes: H01L 23/66 High-frequency adaptations
• 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

A passive electrical device includes a first electrical conductor, a second electrical conductor disposed over the first conductor; and a third electrical conductor connecting the first conductor to the second conductor. The said first, second and third conductors are disposed on a semiconductor substrate. The sheet resistivity of the first conductor is approximately equal to the sheet resistivity of the second conductor.

Claims

1. A passive electrical device, comprising:

a first spiral electrical conductor;

a second spiral electrical conductor disposed over said first electrical conductor;

a third electrical conductor connecting said first electrical conductor to said second electrical conductor, wherein

said first spiral, second spiral and third electrical conductors are disposed on a semiconductor substrate and wherein the resistivity of said first spiral electrical conductor is approximately equal to the resistivity of said second spiral electrical conductor, and wherein said third electrical conductor has a thickness which separates said first electrical conductor from said second electrical conductor by a distance in a range of approximately three microns to approximately four microns and consists essentially of one substantially uniform chemical composition, wherein said second spiral electrical conductor occupies an area of not greater than 150 microns×

150 microns, wherein said first and said second spiral electrical conductors have a coefficient of coupling of approximately 0.9 and wherein said device has an inductance of approximately 1.78 nh.

2. The device as claimed in claim 1, wherein each of said first, second and third electrical conductors has a respective thickness, and the thickness of said first electrical conductor is approximately equal to the thickness of the second electrical conductor.

3. The device as claimed in claim 1, wherein each of said first, second and third electrical conductors has a respective thickness, the thickness of said first electrical conductor being approximately equal to the thickness of the second electrical conductor anti being approximately one-half the thickness of said third conductor.

4. The device as claimed in claim 1, wherein said first, second and third electrical conductors consist essentially of copper.

5. The device as claimed in claim 1, wherein said first and third electrical conductors consist essentially of copper, and said second electrical conductor consists essentially of aluminum.

6. The device as claimed in claim 5, wherein said second electrical conductor has a substantially uniform thickness in a range of approximately four microns to approximately six microns.

7. The device as claimed in claim 1, wherein each of said first and said second electrical conductors has a respective thickness in a range of approximately two to approximately 32 microns.

8. An inductor, comprising:

a semiconductor substrate;

first spiral, second spiral and third electrical conductors provided on said substrate, wherein said first spiral and second spiral electrical conductors each has a resistivity which is approximately equal, and wherein said semiconductor substrate comprises silicon, and wherein said third electrical conductor has a thickness which separates said first electrical conductor from said second electrical conductor by a distance in a range of approximately three microns to approximately four microns and consists essentially of one metal having a substantially uniform chemical composition, wherein said second spiral electrical conductor occupies an area of not greater than 150 microns×

150 microns, wherein said first and said second spiral electrical conductors have a coefficient of coupling of approximately 0.9 and wherein said device has an inductance of approximately 1.78 nh.

9. The inductor as claimed in claim 8, wherein said substrate comprises silicon and germanium.

10. The inductor as claimed in claim 8, wherein said substrate is a silicon on insulator substrate.

11. The inductor as claimed in claim 8, wherein said substrate is a silicon-on-sapphire substrate.

12. The inductor as claimed in claim 8, wherein said second electrical conductor is disposed over said first electrical conductor.