Hybrid subtractive etch/metal fill process for fabricating interconnects
View Patent ↗In one example, a method for fabricating an integrated circuit includes patterning a layer of a first conductive metal, via a subtractive etch process, to form a plurality of lines for connecting semiconductor devices on the integrated circuit. A large feature area is formed outside of the plurality of conductive lines via a metal fill process using a second conductive metal.
1. An integrated circuit comprising:
a wafer;
a layer of dielectric material deposited on the wafer;
a plurality of conductive lines formed on the layer of dielectric material;
a first plurality of vias coupled to the plurality of conductive lines and extending through the layer of dielectric material, wherein interfaces between the plurality of conductive lines and at least some of the first plurality of vias are formed as continuous lines of metal; and
a large feature area formed from a conductive metal or a conductive metal alloy, wherein the large feature area is separate from the first plurality of vias and is positioned outside of the plurality of conductive lines, wherein the large feature area includes an electrical pad.
2. The integrated circuit of claim 1 , wherein the plurality of conductive lines and the first plurality of vias are formed from a metal or a metal alloy.
3. The integrated circuit of claim 1 , wherein at least one of the plurality of conductive lines or the first plurality of vias is formed from copper.
4. The integrated circuit of claim 1 , wherein at least one of the plurality of conductive lines or the first plurality of vias is formed from gold.
5. The integrated circuit of claim 1 , wherein at least one of the plurality of conductive lines or the first plurality of vias is formed from silver.
6. The integrated circuit of claim 1 , wherein the plurality of conductive lines have dimensions smaller than forty nanometers.
7. The integrated circuit of claim 1 , wherein the large feature area is formed from copper.
8. The integrated circuit of claim 1 , wherein the large feature area is formed from gold.
9. The integrated circuit of claim 1 , wherein the large feature area is formed from silver.
10. The integrated circuit of claim 1 , wherein the large feature overlaps with at least one of the plurality of conductive lines.
11. The integrated circuit of claim 1 , wherein at least one via of the first plurality of vias is positioned below the large feature area.
12. The integrated circuit of claim 1 , wherein the large feature area is formed from the same material as the plurality of conductive lines and the first plurality of vias.
13. The integrated circuit of claim 1 , further comprising:
a liner positioned between the layer of dielectric material and each via of the first plurality of vias.
14. The integrated circuit of claim 1 , further comprising:
a liner positioned between the dielectric layer and each line of the plurality of conductive lines.
15. The integrated circuit of claim 1 , further comprising:
an interlayer dielectric layer deposited over the layer of dielectric material; and
a second plurality of vias coupled to the plurality of conductive lines and extending through the interlayer dielectric layer.
16. The integrated circuit of claim 15 , wherein the second plurality of vias is formed from the same material as the first plurality of vias and the plurality of conductive lines.
17. The integrated circuit of claim 1 , wherein the continuous lines of metal are formed from a single metallic material that makes up both the plurality of conductive lines and the at least some of the first plurality of vias.
18. The integrated circuit of claim 17 , wherein the single metallic material is continuously plated into regions of the plurality of conductive lines and the at least some of the first plurality of vias simultaneously.