Airbridge wiring structure for MMIC

• US 5,677,574 A
• Filed: 04/09/1996
• Issued: 10/14/1997
• Est. Priority Date: 04/12/1995
• Status: Expired due to Term

• Current Assignee: Mitsubshi Denki Kabushiki Kaisha
• Original Assignee: Mitsubishi Denki Kabushiki Kaisha (Mitsubishi Electric Corporation)
• Inventors: Hisaka, Takayuki
• Primary Examiner(s): Saadat, Mahshid D.
• Assistant Examiner(s): CLARK, SHEILA V
• Application Number:
  US08/629,535
• Time in Patent Office: 553 Days
• Field of Search: 257/776, 257/775, 257/773
• US Class Current: 257/776
• CPC Class Codes: H01L 21/7682 the dielectric comprising air gaps
• CPC Class Codes: H01L 23/4821 Bridge structure with air gap
• CPC Class Codes: H01L 23/5221 Crossover interconnections
• CPC Class Codes: H01L 23/5381 Crossover interconnections, e.g. bridge stepovers
• 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 airbridge wiring structure includes a substrate having a surface; a first wiring layer disposed on the surface of the substrate; and a second wiring layer disposed partially on the surface of the substrate and including an airbridge wiring layer crossing the first wiring layer, the first and second wiring layers being electrically insulated from each other and separated by an air gap wherein the airbridge wiring layer includes at least one longitudinal groove.

Claims

1. An airbridge wiring structure comprising:

a substrate having a surface;

a first wiring layer disposed on the surface of the substrate; and

a second wiring layer disposed partially on the surface of the substrate and including an airbridge wiring layer crossing the first wiring layer, the first and second wiring layers being electrically insulated from each other and separated by an air gap wherein the first wiring layer is thinner opposite the airbridge wiring layer than elsewhere.

2. The airbridge wiring structure of claim 1 comprising an insulating layer disposed between the first wiring layer and the substrate.

3. The airbridge wiring structure of claim 1 wherein the first wiring layer is disposed at a position lower than the insulating layer.

4. The airbridge wiring structure of claim 1 wherein the airbridge wiring layer is gold in which copper ions are implanted for increasing the strength of the airbridge wiring layer.

5. The airbridge wiring structure of claim 1 wherein the airbridge wiring layer is laminated with a metal film for increasing the mechanical strength of the airbridge wiring layer.

6. The airbridge wiring structure of claim 5 wherein the metal film is tantalum.

7. An airbridge wiring structure comprising:

a substrate having a first surface;

a first wiring layer disposed on the first surface of the substrate; and

a second wiring layer disposed partially on the first surface of the substrate and including an airbridge wiring layer crossing the first wiring layer, the first and second wiring layers being electrically insulated from each other and separated by an air gap wherein the substrate includes a recess in which the first surface is a bottom surface of the recess, and the substrate includes a second surface outside the recess, the recess providing protection to the air bridge wiring structure.

8. The airbridge wiring structure of claim 7 comprising an insulating layer disposed between the first wiring layer and the substrate.

9. The airbridge wiring structure of claim 7 wherein the airbridge wiring layer is gold in which copper ions are implanted for increasing the strength of the airbridge wiring layer.

10. The airbridge wiring structure of claim 7 wherein the airbridge wiring layer is laminated with a metal film for increasing the mechanical strength of the airbridge wiring layer.

11. The airbridge wiring structure of claim 10 wherein the metal film is tantalum.

12. An airbridge wiring structure comprising:

a substrate having a surface;

a first wiring layer disposed on the surface of the substrate; and

a second wiring layer disposed partially on the surface of the substrate and including an airbridge wiring layer crossing the first wiring layer, the first and second wiring layers being electrically insulated from each other and separated by an air gap wherein the airbridge wiring layer includes at least one longitudinal groove transverse to the first wiring layer.

13. The airbridge wiring structure of claim 12 comprising an insulating layer disposed between the first wiring layer and the substrate.

14. The airbridge wiring structure of claim 12 wherein the groove includes an opening directed away from the substrate.

15. The airbridge wiring structure of claim 12 wherein the groove includes an opening directed toward the substrate.

16. The airbridge wiring structure of claim 12 wherein the airbridge wiring layer includes a plurality of longitudinal grooves.

17. The airbridge wiring structure of claim 12 wherein the airbridge wiring layer includes two oppositely directed longitudinal grooves.

18. The airbridge wiring structure of claim 12 wherein the airbridge wiring layer is gold in which copper ions are implanted for increasing the strength of the airbridge wiring layer.

19. The airbridge wiring structure of claim 12 wherein the airbridge wiring layer is laminated with a metal film for increasing the mechanical strength of the airbridge wiring layer.

20. The airbridge wiring structure of claim 19 wherein the metal film is tantalum.

21. An airbridge wiring structure comprising:

a substrate having a surface;

a first wiring layer disposed on the surface of the substrate; and

a second wiring layer disposed partially on the surface of the substrate and including an airbridge wiring layer crossing the first wiring layer, the first and second wiring layers being electrically insulated from each other and separated by an air gap wherein the airbridge wiring layer includes a plurality of holes opposite the first wiring layer.

22. The airbridge wiring structure of claim 21 wherein the airbridge wiring layer is gold in which copper ions are implanted for increasing the strength of the airbridge wiring layer.

23. The airbridge wiring structure of claim 21 wherein the airbridge wiring layer is laminated with a metal film for increasing the mechanical strength of the airbridge wiring layer.

24. The airbridge wiring structure of claim 22 wherein the metal film is tantalum.

25. An airbridge wiring structure comprising:

a substrate having a surface;

a single electrically conducting region within a portion of and at the surface of the substrate and a first wiring layer having two parts disposed on the surface of the substrate, the two parts being electrically connected through the single electrically conducting region; and

a second wiring layer partially disposed on the surface of the substrate and including an airbridge wiring layer crossing the single electrically conducting region wherein the single electrically conducting region and the airbridge wiring layer are electrically insulated from each other and separated by an air gap.

26. The airbridge wiring structure of claim 25 wherein the airbridge wiring layer is gold in which copper ions are implanted for increasing the strength of the airbridge wiring layer.

27. The airbridge wiring structure of claim 25 wherein the airbridge wiring layer is laminated with a metal film for increasing the mechanical strength of the airbridge wiring layer.

28. The airbridge wiring structure of claim 27 wherein the metal film is tantalum.