Wrapped contacts with enhanced area
Semiconductor devices include semiconductor fins and fin extensions formed on the semiconductor fins that extend vertically and laterally beyond boundaries of the plurality of semiconductor fins. A first dielectric layer is formed on sidewalls of the semiconductor fins and between the semiconductor fins. A conductive liner is formed on the fin extensions that covers a top surface of the first dielectric layer between the semiconductor fins. A conductive contact is formed on the conductive liner.
1. A semiconductor device, comprising:
a plurality of semiconductor fins, grouped into at least two regions;
fin extensions formed on the plurality of semiconductor fins that extend vertically and laterally beyond boundaries of the plurality of semiconductor fins;
a first dielectric layer, formed on sidewalls of the plurality of semiconductor fins and between the plurality of semiconductor fins within regions and between regions;
a shallow trench isolation structure positioned between regions on the first dielectric layer, having a bottom surface that is lower than a top surface of the first dielectric layer and having a lower portion, with lower sidewalls that taper toward the bottom surface, and an upper portion, with upper sidewalls that have a slope different from the lower sidewalls;
a conductive liner on the fin extensions that entirely covers the top surface of the first dielectric layer between the plurality of semiconductor fins and that entirely covers sidewalls of the shallow trench isolation structure; and
a conductive contact formed on the conductive liner.
2. The semiconductor device of claim 1 , wherein the first dielectric layer rises to a height above top surfaces of the plurality of semiconductor fins.
3. The semiconductor device of claim 1 , wherein the fin extensions of each semiconductor fin do not contact one another.
4. The semiconductor device of claim 1 , wherein the shallow trench isolation structure bounds a sidewall of the conductive contact.
5. The semiconductor device of claim 4 , wherein the first dielectric layer is formed from silicon nitride and wherein the shallow trench isolation structure is formed from silicon dioxide.
6. The semiconductor device of claim 1 , wherein the conductive liner is formed from a first conductive material and the conductive contact is formed from a second conductive material.
7. The semiconductor device of claim 1 , wherein the conductive liner comprises a material selected from the group consisting of titanium, nickel, cobalt.
8. The semiconductor device of claim 1 , wherein the conductive contact comprises a material selected from the group consisting of tungsten, copper, aluminum, gold, silver, and alloys thereof.
9. The semiconductor device of claim 1 , wherein the lower portion has a height that is higher than the top surface of the first dielectric layer.
10. The semiconductor device of claim 1 , wherein each region includes multiple fins of the plurality of semiconductor fins.