Selective growth for high-aspect ratio metal fill
An improved conductive feature for a semiconductor device and a technique for forming the feature are provided. In an exemplary embodiment, the semiconductor device includes a substrate having a gate structure formed thereupon. The gate structure includes a gate dielectric layer disposed on the substrate, a growth control material disposed on a side surface of the gate structure, and a gate electrode fill material disposed on the growth control material. The gate electrode fill material is also disposed on a bottom surface of the gate structure that is free of the growth control material. In some such embodiments, the gate electrode fill material contacts a first surface and a second surface that are different in composition.
1. A device comprising:
a fin structure disposed on a semiconductor substrate; and
a gate structure disposed over the fin structure, wherein the gate structure includes:
a gate dielectric layer disposed on the fin structure;
a barrier layer disposed over the gate dielectric layer, the barrier layer having a first sidewall and a second opposing sidewall such that a bottom surface of the barrier layer extends from the first sidewall to the second sidewall of the barrier layer;
a growth control material disposed on at least one of the first and second sidewalls of the barrier layer without being disposed on the bottom surface of the barrier layer, wherein the growth control material is disposed directly on the first and second sidewalls of the barrier layer such that that the growth control material physically contacts the first and second sidewalls of the barrier layer; and
a gate electrode fill material disposed on the growth control material and on the bottom surface of the barrier layer.
2. The device of claim 1 , wherein the gate structure further includes a work function metal layer disposed on the gate dielectric layer such that the work function metal layer is disposed between the gate dielectric layer and the barrier layer.
3. The device of claim 2 , wherein the gate structure further includes a wetting layer disposed on the work function metal layer such that the wetting layer is disposed between the work function metal layer and the barrier layer.
4. The device of claim 1 , wherein the growth control material is disposed along the first sidewall of the barrier layer, and
wherein the growth control material has a first thickness along an upper portion of the first sidewall and a second thickness along a lower portion of the first sidewall, the first thickness being different than the second thickness.
5. The device of claim 1 , wherein the growth control material has an edge facing the fin structure, and
wherein the gate electrode fill material extends from the edge of the growth control material to the bottom surface of the barrier layer.
6. The device of claim 1 , wherein the growth control material includes a material selected from the group consisting of a metal oxide material, a metal carbide material, and a metal nitride material.
7. A device comprising:
a gate structure disposed over a semiconductor substrate, wherein the gate structure includes:
a gate dielectric layer disposed over the semiconductor substrate;
a metal containing layer disposed over the gate dielectric layer, the metal containing layer having a first sidewall and a second opposing sidewall such that a bottom surface of the metal containing layer extends from the first sidewall to the second sidewall of the metal containing;
a growth control material disposed along the first and second sidewalls of the metal containing layer without being disposed on the bottom surface of the metal containing layer; and
a gate electrode fill material disposed directly on the growth control material and disposed directly on the bottom surface of the metal containing layer.
8. The device of claim 7 , wherein the metal containing layer is formed of a different material than the growth control material.
9. The device of claim 7 , wherein a top surface of the metal containing layer and top surface of the growth control material are substantially coplanar.
10. The device of claim 7 , wherein the gate electrode fill material has a first width along an upper portion of the gate structure and a second width along a lower portion of the gate structure, the first width being different than the second width.
11. The device of claim 7 , further comprising a fin structure dispose on the semiconductor substrate, and
wherein the gate structure is disposed over the fin structure.
12. The device of claim 7 , wherein the gate structure further includes a work function metal layer disposed on the gate dielectric layer such that the work function metal layer is disposed between the gate dielectric layer and the metal containing layer.
13. The device of claim 12 , wherein the gate structure further includes a wetting layer disposed on the work function metal layer such that the wetting layer is disposed between the work function metal layer and the metal containing layer.
14. The device of claim 7 , wherein the growth control material includes a metal carbide material.
15. A semiconductor device comprising:
a substrate having a gate structure formed thereupon, wherein the gate structure includes:
a gate dielectric layer disposed on the substrate;
a growth control material disposed on a side surface of the gate structure;
a gate electrode fill material disposed on the growth control material and on a bottom surface of the gate structure that is free of the growth control material; and
a barrier layer disposed between the growth control material and the gate dielectric layer and between the gate electrode fill material and the gate dielectric layer, wherein the barrier layer is different in composition from the growth control material.
16. The semiconductor device of claim 15 , wherein the growth control material includes at least one of a metal carbide or a metal nitride, and wherein the growth control material and the gate electrode fill material contain at least one metal in common.
17. The semiconductor device of claim 15 , wherein the gate electrode fill material contacts a surface of the growth control material and a surface of the barrier layer that are different in composition.
18. The semiconductor device of claim 15 , wherein the growth control material has a thickness of less than about 20 Å.
19. The device of claim 1 , wherein the gate electrode fill material extends between the growth control material and the bottom surface of the barrier layer.
20. The semiconductor device of claim 15 , wherein the growth control material physically contacts a first portion of a sidewall of the barrier layer and the gate electrode fill material physically contacts a second portion of the sidewall of the barrier layer.