Metal silicate spacers for fully aligned vias
A multi-level semiconductor device and a method of fabricating a multi-level semiconductor device involve a first interlayer dielectric (ILD) layer with one or more metal lines formed therein. A silicide is formed on a surface of the first ILD layer and is directly adjacent to each of the one or more metal lines on both sides of each of the one or more metal lines. A second ILD is formed above the silicide, and a via is formed through the second ILD above one of the one or more metal lines. One or more second metal lines are formed above the second ILD, one of which is formed in the via. The second metal line in the via contacts the one of the one or more metal lines and the silicide adjacent to the one of the one or more metal lines.
1. A multi-level semiconductor device, comprising:
a first interlayer dielectric (ILD) layer with one or more metal lines formed therein;
a silicide formed on a surface of the first ILD layer, wherein the silicide is directly adjacent to each of the one or more metal lines on both sides of each of the one or more metal lines;
a second ILD formed above the silicide;
a via formed through the second ILD above one of the one or more metal lines; and
one or more second metal lines formed above the second ILD, wherein one of the one or more second metal lines is formed in the via, and the second metal line in the via contacts the one of the one or more metal lines and the silicide adjacent to the one of the one or more metal lines.
2. The device according to claim 1 , wherein the silicide is formed on the surface of the first ILD layer conformally.
3. The device according to claim 1 , further comprising a dielectric cap formed directly on the silicide, wherein the second ILD is formed on the dielectric cap.
4. The device according to claim 3 , wherein the dielectric cap is formed on the silicide conformally.
5. The device according to claim 3 , wherein the dielectric cap includes silicon nitride (Si 3 N 4 ), silicon carbide (SiC), silicon carbonitride (SiCN), or hydrogen silicon carbide (SiCH).
6. The device according to claim 1 , wherein the one or more metal lines and the one or more second metal lines are perpendicular to each other.
7. The device according to claim 1 , wherein two or more second metal lines are separated from each other by the second ILD.
8. The device according to claim 1 , wherein a second of the one or more second metal lines contacts a second of the one or more metal lines through a second via.
9. The device according to claim 8 , wherein the second of the one or more second metal lines contacts the silicide that is directly adjacent to the second of the one or more metal lines.
10. The device according to claim 1 , wherein none of the one or more second metal lines extends below a top surface of any of the one or more metal lines.
11. The device according to claim 1 , wherein the first ILD layer is a dielectric.
12. The device according to claim 1 , wherein the first ILD layer includes porous silicates, carbon doped oxides, silicon dioxides, silicon nitrides, or silicon oxynitrides.
13. The device according to claim 1 , wherein the metal lines include a metal liner.
14. The device according to claim 13 , wherein the metal liner includes tantalum nitride and tantalum (TaN/Ta), titanium, titanium nitride, cobalt, ruthenium, or manganese.
15. The device according to claim 1 , wherein the metal lines include copper (Cu), aluminum (Al), or tungsten (W).
16. The device according to claim 1 , wherein the first ILD and the second ILD are comprised of a same material.
17. The device according to claim 1 , wherein the via has a rectangular shape.
18. The device according to claim 1 , wherein the via exposes a top surface of the one of the one or more metal lines and a portion of the silicide adjacent to the one of the one or more metal lines.
19. The device according to claim 1 , wherein the one or more metal lines and the one or more second metal lines are comprised of a same material.
20. The device according to claim 1 , wherein the one or more metal lines and the one or more second metal lines are comprised of different materials.