Methods of manufacturing copper interconnect systems
View Patent ↗An integrated circuit (IC) may include a substrate, a first dielectric layer adjacent the substrate, and at least one trench in the first dielectric layer. The IC may also include a metal liner within the at least one trench, and a first conductive region including copper within the at least one trench. A cap layer including metal may be provided on the first conductive region. A second dielectric layer may be over the first conductive region and the cap layer. A dielectric etch stop and diffusion barrier layer may be over the second dielectric layer, and a via may be over the first conductive region and through the second dielectric layer and the cap layer. A diffusion barrier layer may be on sidewalls of the via, and an alloy seed layer including copper and at least one of tantalum, molybdenum, chromium, and tungsten may be over the diffusion barrier. The alloy seed layer may also be over the dielectric etch stop and diffusion barrier layer, and the alloy seed layer may be in contact with the first conductive region.
1. A method of manufacturing an integrated circuit comprising:
forming a copper based interconnect in a first dielectric layer, said first dielectric layer being adjacent to a substrate;
adding a cap layer comprising metal to a surface of said copper based interconnect, thereby forming a capped interconnect;
forming a second dielectric layer over said capped interconnect;
forming a via in said second dielectric layer;
removing a portion of said cap layer situated in said via;
forming a diffusion barrier layer on sidewalls of said via; and
depositing an alloy seed layer comprising copper in said via, said alloy seed layer in contact with and over said copper based interconnect.
2. A method of manufacturing an integrated circuit according to claim 1 wherein said diffusion barrier layer is conductive.
3. A method of manufacturing an integrated circuit according to claim 1 wherein said alloy seed layer further comprises at least one of tantalum, molybdenum, chromium, and tungsten.
4. A method of manufacturing an integrated circuit according to claim 1 , further comprising forming at least one trench in said first dielectric layer, and forming said copper based interconnect within said at least one trench.
5. A method of manufacturing an integrated circuit according to claim 1 , wherein said cap layer comprises at least one of palladium and platinum.
6. A method of manufacturing an integrated circuit according to claim 1 , further comprising depositing a solid solution at the interface of said copper based interconnect and said cap layer.
7. A method of manufacturing an integrated circuit according to claim 1 , further comprising forming a dielectric etch stop and diffusion barrier layer over said second dielectric layer.
8. A method of manufacturing an integrated circuit according to claim 1 , further comprising forming a conductive region comprising copper over said alloy seed layer.
9. A method of manufacturing an integrated circuit comprising:
forming a copper based interconnect in a first dielectric layer, said first dielectric layer being adjacent to a substrate;
adding a cap layer comprising metal to a surface of said copper based interconnect, thereby forming a capped interconnect;
forming a second dielectric layer over said capped interconnect;
forming a via in said second dielectric layer;
removing a portion of said metal-based cap layer situated in said via;
forming a first diffusion barrier layer on sidewalls of said via; and
forming a second diffusion barrier over horizontal surfaces of said via; and
said first diffusion barrier being a different material than said second diffusion barrier.
10. A method of manufacturing an integrated circuit according to claim 9 further comprising an alloy seed layer over said first and second diffusion barriers.
11. A method of manufacturing an integrated circuit according to claim 10 wherein said alloy seed layer comprises copper and at least one of tantalum and chromium.
12. A method of manufacturing an integrated circuit according to claim 9 further comprising a dielectric diffusion barrier over said cap layer.
13. A method of manufacturing an integrated circuit according to claim 9 wherein said copper based interconnect comprises a copper interconnect.
14. A method of manufacturing an integrated circuit according to claim 9 wherein said cap layer comprises at least one of palladium and platinum.
15. A method of manufacturing an integrated circuit according to claim 9 , further comprising a solid solution at the interface of said copper based interconnect and said cap layer.
16. A method of manufacturing an integrated circuit according to claim 9 , further comprising a dielectric etch stop and diffusion barrier layer over said second dielectric layer.
17. A method of manufacturing an integrated circuit comprising:
forming a copper based interconnect in a first dielectric layer, said first dielectric layer being adjacent to a substrate;
forming a diffusion barrier and cap layer comprising a metal and a conductive oxide of said metal over said copper based interconnect, thereby forming a capped interconnect;
forming a second dielectric layer over said diffusion barrier and cap layer.
18. A method of manufacturing an integrated circuit according to claim 17 wherein said diffusion barrier and cap layer comprises Ru and Ru oxide.
19. A method of manufacturing an integrated circuit according to claim 17 further comprising forming an alloy seed layer over said diffusion barrier and cap layer.
20. A method of manufacturing an integrated circuit according to claim 19 wherein said alloy seed layer comprises copper and at least one of tantalum and chromium.
21. A method of manufacturing an integrated circuit according to claim 19 , further comprising forming a second conductive region comprising copper over said alloy seed layer.
22. A method of manufacturing an integrated circuit according to claim 17 , further comprising depositing a solid solution at an interface of said copper based interconnect and said cap layer.
23. A method of manufacturing an integrated circuit according to claim 17 , further comprising forming a dielectric etch stop and diffusion barrier layer over said second dielectric layer.