Structures of and methods and tools for forming in-situ metallic/dielectric caps for interconnects
View Patent ↗A structure, tool and method for forming in-situ metallic/dielectric caps for interconnects. The method includes forming wire embedded in a dielectric layer on a semiconductor substrate, the wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of the copper core, a top surface of the wire coplanar with a top surface of the dielectric layer; forming a metal cap on an entire top surface of the copper core; without exposing the substrate to oxygen, forming a dielectric cap over the metal cap, any exposed portions of the liner, and the dielectric layer; and wherein the dielectric cap is an oxygen diffusion barrier and contains no oxygen atoms.
1. A method comprising:
(a) forming wire embedded in a dielectric layer on a semiconductor substrate, said wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of said copper core, a top surface of said copper core, a top surface of said electrically conductive liner and a top surface of said dielectric layer are coplanar;
(b) forming a metal cap on an entire top surface of said copper core;
(c) without exposing said substrate to oxygen, forming a dielectric cap on exposed surfaces of said metal cap, on all exposed surfaces of said liner, and on said top surface of said dielectric layer; and
wherein said dielectric cap is an oxygen diffusion barrier and contains no oxygen atoms.
2. The method of claim 1 , wherein:
(b) and (c) are performed in a same chamber of a first deposition tool without removing said substrate from said chamber; or
(b) and (c) are performed in a different chambers of a second deposition tool without removing said substrate from said tool.
3. The method of claim 1 , wherein said metal cap is formed by either selective chemical vapor deposition or selective atomic layer deposition and said dielectric cap is formed by chemical vapor deposition.
4. The method of claim 1 , where in said metal cap is a metal selected from the group consisting of ruthenium, cobalt, titanium, palladium, nickel, gold, iridium, manganese and combinations thereof.
5. The method of claim 1 , wherein said dielectric cap comprises silicon nitride, silicon carbide, amorphous silicon carbonitride or combinations thereof.
6. The method of claim 1 , further including:
between (b) and (c), (d) without exposing said substrate to oxygen, forming an alloy cap on said metal cap; and
wherein (c) includes forming said dielectric cap on said alloy cap, any exposed regions of said metal cap, any exposed portions of said liner, and said dielectric layer.
7. The method of claim 6 , wherein:
(b), (c) and (d) are performed in a same chamber of a first deposition tool without removing said substrate from said chamber; or
(b) and (d) are performed in a first chamber and (c) is performed in a third chamber of a second deposition tool; or
(b), (d) and (c) are performed in different chambers of a third deposition tool.
8. The method of claim 6 , wherein said metal cap is formed by either selective chemical vapor deposition or selective atomic layer deposition, said alloy cap is formed by either selective chemical vapor deposition or selective atomic layer deposition, and said dielectric cap is formed by chemical vapor deposition.
9. The method of claim 6 , wherein said alloy cap comprises RuP, RuB, RuW, RuPW, RuPB, RuBW, RuPBW, CoP, CoB, CoW, CoPW, CoPB, CoBW, CoPBW, MnP, MnB, MnW, MnPW, MnPB, MnBW or MnPBW.
10. The method of claim 6 , further including:
between (a) and (b), recessing a top surface of said copper core below said top surface of said dielectric layer.
11. The method of claim 1 , further including:
between (a) and (b), recessing a top surface of said copper core below said top surface of said dielectric layer.
12. A structure, comprising:
a wire embedded in a dielectric layer on a semiconductor substrate, said wire comprising a copper core and an electrically conductive liner on sidewalls and a bottom of said copper core, said copper core and said electrically conductive liner exposed at a top surface of said dielectric layer;
a metal cap on an entire top surface of said copper core;
a dielectric cap only over (i) said metal cap, (ii) any exposed portions of said liner, and (iii) on said top surface of said dielectric layer; and
wherein an interface between said copper core and said metal layer does not contain oxygen.
13. The structure of claim 12 , wherein said dielectric cap is an oxygen diffusion barrier.
14. The structure of claim 12 , wherein (i) said metal cap is a metal selected from the group consisting of ruthenium, cobalt, titanium, palladium, nickel, gold, iridium, manganese and combinations thereof and (ii) said dielectric cap comprises silicon nitride, silicon carbide, amorphous silicon carbonitride or combinations thereof.
15. The structure of claim 12 , further including:
an alloy cap on said metal cap; and
wherein said dielectric cap is formed on said alloy cap, any exposed regions of said metal cap, any exposed portions of said liner, and said dielectric layer.
16. The structure of claim 15 , wherein said alloy cap comprises RuP, RuB, RuW, RuPW, RuPB, RuBW, RuPBW, CoP, CoB, CoW, CoPW, CoPB, CoBW, CoPBW, MnP, MnB, MnW, MnPW, MnPB, MnBW or MnPBW.
17. The structure of claim 15 , wherein a top surface of said copper core and said electrically conductive liner are coplanar with said top surface of said dielectric layer.
18. The structure of claim 15 , wherein a top surface said electrically conductive liner is coplanar with said top surface of said dielectric layer and a top surface of said copper core is recessed below said top surface of said dielectric layer.
19. The structure of claim 12 , wherein a top surface of said copper core, top edges of said electrically conductive liner on said sidewalls of said copper core and said top surface of said dielectric layer are coplanar.
20. The structure of claim 12 , wherein a top surface said electrically conductive liner is coplanar with said top surface of said dielectric layer and a top surface of said copper core is recessed below said top surface of said dielectric layer.
21. The method of claim 1 , wherein, after said forming said metal cap said top surface of said wire remains coplanar with said top surface of said dielectric layer.
22. The method of claim 1 , wherein said metal cap is a single layer of metal selected from the group consisting of ruthenium, cobalt, titanium, palladium, nickel, gold, iridium, manganese and combinations thereof.
23. The method of claim 1 , wherein said capping layer extends over a perimeter region of said electrically conductive liner.
24. The method of claim 1 , wherein electrically conductive liner comprise a first liner on said sidewalls and bottom of said copper core and a second liner on said first liner, said capping layer extend completely over said first liner.
25. The method of claim 12 , wherein said capping layer extends over a perimeter region of said electrically conductive liner.
26. The method of claim 12 , wherein electrically conductive liner comprise a first liner on said sidewalls and bottom of said copper core and a second liner on said first liner, said capping layer extend completely over said first liner.