Shapes-based migration of aluminum designs to copper damascene
View Patent ↗An interconnect structure, method of fabricating the interconnect structure and method of designing the interconnect structure for use in semiconductor devices. The interconnect structure includes a damascene metal wire having a pattern of dielectric filled holes.
1. An integrated circuit, comprising:
a dielectric layer having a bottom surface disposed over a semiconductor substrate;
a wire comprising a metal filled trench filled with a layer of metal in said dielectric layer, said metal filled trench extending from a top surface of said dielectric layer toward said bottom surface of said dielectric layer;
a set of metal fill shapes filled with said layer of metal in said dielectric layer, said set of metal fill shapes extending from a top surface of said dielectric layer toward said bottom surface of said dielectric layer, said metal fill shapes not contacting said wire; and
a plurality of dielectric pedestals disposed in said wire, said dielectric pedestals filled with said dielectric layer, said dielectric pedestals extending from a top surface of said metal filled trench to a bottom surface of said metal filled trench, said dielectric pedestals arranged in an offset-grid of rows and columns, wherein dielectric pedestals in different rows are displaced in a column wise direction from each other.
2. The integrated circuit of claim 1 , wherein said layer of metal comprises copper.
3. The integrated circuit of claim 1 , wherein said metal filled trench and said dielectric pedestals extend to said bottom surface of said dielectric layer.
4. The integrated circuit of claim 1 , wherein a first region of said metal filled trench extends from said top surface to said bottom surface of said dielectric layer and wherein a second region of said metal filled trench and said dielectric pedestals extend from said top surface of said dielectric layer toward said bottom surface of said dielectric layer and does not extend to said bottom surface of said dielectric layer.
5. The integrated circuit of claim 1 , wherein a length of each side of said dielectric pedestals is three times a design rule minimum width for said wire.
6. The integrated circuit of claim 1 , wherein a ratio of the combined areas of said dielectric pedestals to the area of said wire does not exceed 0.20.
7. The integrated circuit of claim 1 , further comprising:
an additional wire comprising an additional metal filled trench filled with said layer of metal in said dielectric layer, said additional metal filled trench extending from a top surface of said dielectric layer toward said bottom surface of said dielectric layer;
a plurality of additional dielectric pedestals disposed in said additional wire, said additional dielectric pedestals filled with said dielectric layer, said additional dielectric pedestals extending from a top surface of said metal filled trench to a bottom surface of said metal filled trench, said additional dielectric pedestals arranged in an additional offset-grid of rows and columns, wherein dielectric pedestals in different rows are displaced in a column wise direction from each other.
8. The integrated circuit of claim 7 , wherein:
said dielectric pedestals and said additional dielectric pedestals have a square shape when viewed from a direction perpendicular to a top surface of said substrate.
9. The integrated circuit of claim 7 , wherein said additional metal filled trench and said additional dielectric pedestals extend to said bottom surface of said dielectric layer.
10. The integrated circuit of claim 7 , wherein a first region of said additional metal filled trench extends from said top surface to said bottom surface of said dielectric layer and wherein a second region of said additional metal filled trench and said dielectric pedestals extend from said top surface of said dielectric layer toward said bottom surface of said dielectric layer and does not extend to said bottom surface of said dielectric layer.
11. The integrated circuit of claim 7 , wherein:
said first wire has a first width, said dielectric pedestals have a second width less than said first width and said dielectric pedestals are spaced apart a first distance;
said additional wire has a third width, said additional dielectric pedestals have a fourth width less than said third width and said additional dielectric pedestals are spaced apart a second distance; and
said second width divided by said first distance is equal to said fourth width divided by said second distance.
12. The integrated circuit of claim 11 , wherein said first width is greater than said width, said second width is greater than said fourth width, and said first distance is greater than said second distance.
13. The integrated circuit of claim 7 , wherein:
said first wire has a first width, said dielectric pedestals have a second width less than said first width and said dielectric pedestals are spaced apart a first distance;
said additional wire has a third width, said additional dielectric pedestals have a fourth width less than said third width and said additional dielectric pedestals are spaced apart a second distance; and
said first width divided by said second width is equal to said third width divided by said fourth width and said second width divided by said first distance is equal to said fourth width divided by said second distance.
14. The integrated circuit of claim 13 , wherein said first width is greater than said width, said second width is greater than said fourth width, and said first distance is greater than said second distance.
15. The integrated circuit of claim 7 , wherein said additional dielectric pedestals are square when viewed from a direction perpendicular to a top surface of said substrate.
16. The integrated circuit of claim 7 , wherein a length of each side of said additional dielectric pedestals is three times a design rule minimum width for said additional wire.
17. The integrated circuit of claim 7 , wherein a ratio of the combined areas of said additional dielectric pedestals to an area of said additional wire does not exceed 0.20.
18. The integrated circuit of claim 1 , wherein a ratio of an area of all metal fill shapes in a region of said dielectric layer containing said metal fill shapes to an area of said region is about 0.45.
19. The integrated circuit of claim 1 , further comprising:
an additional dielectric layer formed on said top surface of said dielectric layer;
an additional wire in said additional dielectric layer, said additional wire extending from a top surface of said additional dielectric layer to a bottom surface of said additional dielectric layer, said wire contacting said wire and at least one dielectric pedestal of said plurality of dielectric pedestals.
20. The integrated circuit of claim 7 , further comprising:
an additional dielectric layer formed on said top surface of said dielectric layer;
a second additional wire in said additional dielectric layer, said second additional wire extending from a top surface of said additional dielectric layer to a bottom surface of said additional dielectric layer, said second additional wire contacting said wire and at least one dielectric pedestal of said plurality of dielectric pedestals.