Diffusion barriers for copper interconnect systems

• US 6,441,492 B1
• Filed: 09/28/2000
• Issued: 08/27/2002
• Est. Priority Date: 09/10/1999
• Status: Expired due to Term

• Current Assignee: Liberty Patents LLC
• Original Assignee: James A. Cunningham
• Inventors: Cunningham, James A.
• Primary Examiner(s): Tran, Minh Loan
• Assistant Examiner(s): Dickey, Thomas L.
• Application Number:
  US09/672,473
• Time in Patent Office: 698 Days
• Field of Search: 257/748, 257/750-754, 257/762-764
• US Class Current: 257/762
• CPC Class Codes: H01L 21/76843 formed in openings in a dielectric
• CPC Class Codes: H01L 21/76846 Layer combinations
• CPC Class Codes: H01L 21/76849 the layer being positioned on top of the main fill metal
• CPC Class Codes: H01L 21/76867 characterized by methods of formation other than PVD, CVD or deposition from a liquids PVD H01L21/2855; CVD H01L21/28556; deposition from liquids H01L21/288
• CPC Class Codes: H01L 21/76873 for electroplating
• CPC Class Codes: H01L 21/76877 Filling of holes, grooves or trenches, e.g. vias, with conductive material
• CPC Class Codes: H01L 21/76886 Modifying permanently or temporarily the pattern or the conductivity of conductive members, e.g. formation of alloys, reduction of contact resistances
• CPC Class Codes: H01L 23/5226 Via connections in a multilevel interconnection structure
• CPC Class Codes: H01L 23/53238 Additional layers associated with copper layers, e.g. adhesion, barrier, cladding layers
• 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 includes a substrate, at least one dielectric layer adjacent the substrate, and an interconnect structure in the at least one dielectric layer and comprising a copper portion and a barrier layer between the copper portion and adjacent portions of the at least one dielectric layer. Moreover, the barrier layer preferably comprises at least one of rhodium, ruthenium and rhenium. These materials are virtually insoluble and immiscible in copper, and can be readily deposited by electroless deposition, for example. The barrier layer may be in contact with the adjacent portions of the at least one dielectric layer. In addition, at least one other barrier layer can be provided between the barrier layer and the copper portion. The interconnect structure in some embodiments may extend both laterally and vertically within the at least one dielectric layer.

Claims

1. An integrated circuit comprising:

a substrate;

at least one dielectric layer adjacent said substrate; and

an interconnect structure in said at least one dielectric layer and comprising a copper portion and a copper-diffusion barrier layer between said copper portion and adjacent portions of said at least one dielectric layer;

said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium.

2. An integrated circuit according to claim 1 wherein said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium is in contact with the adjacent portions of the at least one dielectric layer.

3. An integrated circuit according to claim 2 further comprising at least one other copper-diffusion barrier layer between said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium and said copper portion.

4. An integrated circuit according to claim 1 wherein said interconnect structure extends both laterally and vertically within said at least one dielectric layer.

5. An integrated circuit according to claim 1 wherein said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium further comprises at least one of chromium, tungsten, tantalum, and molybdenum.

6. An integrated circuit according to claim 1 wherein said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium further comprises silicon.

7. An integrated circuit according to claim 1 further comprising an adhesion layer between said copper-diffusion barrier layer comprising at least one of rhodium, ruthenium and rhenium and adjacent portions of said at least one dielectric layer.

8. An integrated circuit according to claim 7 wherein said adhesion layer comprises titanium.

9. An integrated circuit according to claim 1 wherein said copper portion comprises a copper alloy.

10. An integrated circuit according to claim 1 wherein said copper portion comprises at least one of calcium, cadmium, zinc, neodymium, tellurium, and ytterbium as a dopant.

11. An integrated circuit comprising:

a substrate;

at least one dielectric layer adjacent said substrate; and

an interconnect structure in said at least one dielectric layer and comprising a copper portion and a copper-diffusion barrier layer between said copper portion and adjacent portions of said at least one dielectric layer;

said copper-diffusion barrier layer comprising rhodium.

12. An integrated circuit according to claim 11 wherein said rhodium copper-diffusion barrier layer is in contact with the adjacent portions of the at least one dielectric layer.

13. An integrated circuit according to claim 12 further comprising at least one other copper-diffusion barrier layer between said rhodium copper-diffusion barrier layer and said copper portion.

14. An integrated circuit according to claim 11 wherein said interconnect structure extends both laterally and vertically within said at least one dielectric layer.

15. An integrated circuit according to claim 11 wherein said rhodium copper-diffusion barrier layer further comprises at least one of chromium, tungsten, tantalum, and molybdenum.

16. An integrated circuit according to claim 11 wherein said rhodium copper-diffusion barrier layer further comprises silicon.

17. An integrated circuit according to claim 11 wherein said copper portion comprises a copper alloy.

18. An integrated circuit according to claim 11 wherein said copper portion comprises at least one of calcium, cadmium, zinc, neodymium, tellurium, and ytterbium as a dopant.

19. An integrated circuit comprising:

a substrate;

at least one dielectric layer adjacent said substrate; and

an interconnect structure in said at least one dielectric layer and comprising a copper portion and a copper-diffusion barrier layer between said copper portion and adjacent portions of said at least one dielectric layer;

said copper-diffusion barrier layer comprising ruthenium.

20. An integrated circuit according to claim 19 wherein said ruthenium copper-diffusion barrier layer is in contact with the adjacent portions of the at least one dielectric layer.

21. An integrated circuit according to claim 20 further comprising at least one other copper diffusion barrier layer between said ruthenium copper-diffusion barrier layer and said copper portion.

22. An integrated circuit according to claim 19 wherein said interconnect structure extends both laterally and vertically within said at least one dielectric layer.

23. An integrated circuit according to claim 19 wherein said ruthenium copper-diffusion barrier layer further comprises at least one of chromium, tungsten, tantalum, and molybdenum.

24. An integrated circuit according to claim 19 wherein said ruthenium copper-diffusion barrier layer further comprises silicon.

25. An integrated circuit according to claim 19 wherein said copper portion comprises a copper alloy.

26. An integrated circuit according to claim 19 wherein said copper portion comprises at least one of calcium, cadmium, zinc, neodymium, tellurium, and ytterbium as a dopant.

27. An integrated circuit comprising:

a substrate;

at least one dielectric layer adjacent said substrate; and

an interconnect structure in said at least one dielectric layer and comprising a copper portion and a copper-diffusion barrier layer between said copper portion and adjacent portions of said at least one dielectric layer;

said copper-diffusion barrier layer comprising rhenium.

28. An integrated circuit according to claim 27 wherein said rhenium copper-diffusion barrier layer is in contact with the adjacent portions of the at least one dielectric layer.

29. An integrated circuit according to claim 28 further comprising at least one other copper-diffusion barrier layer between said rhenium copper-diffusion barrier layer and said copper portion.

30. An integrated circuit according to claim 27 wherein said interconnect structure extends both laterally and vertically within said at least one dielectric layer.

31. An integrated circuit according to claim 27 wherein said rhenium copper-diffusion barrier layer further comprises at least one of chromium, tungsten, tantalum, and molybdenum.

32. An integrated circuit according to claim 27 wherein said rhenium copper-diffusion barrier layer further comprises silicon.

33. An integrated circuit according to claim 27 wherein said copper portion comprises a copper alloy.

34. An integrated circuit according to claim 27 wherein said copper portion comprises at least one of calcium, cadmium, zinc, neodymium, tellurium, and ytterbium as a dopant.