Selective deposition method to form air gaps
A method for depositing a film to form an air gap within a semiconductor device is disclosed. An exemplary method comprises pulsing a metal halide precursor onto the substrate and pulsing an oxygen precursor onto a selective deposition surface. The method can be used to form an air gap to, for example, reduce a parasitic resistance of the semiconductor device.
1. A semiconductor device, the device comprising:
a first column disposed on a surface of a substrate, wherein the first column comprises a first layer and a second layer, wherein the first layer is disposed beneath the second layer;
a second column disposed on a surface of a substrate, wherein the second column comprises a third layer and a fourth layer, wherein the third layer is disposed beneath the fourth layer;
a film connecting the second layer to the fourth layer such that the film defines an air gap beneath the film and between the first and second column,
wherein the film is in direct contact with the second layer and the fourth layer, and wherein the second layer and the fourth layer comprise a material comprising a metal element.
2. The device of claim 1 , wherein the second layer and the fourth layer comprise the same material.
3. The device of claim 1 , wherein the first layer and the third layer comprise a metal or a metallic material.
4. The device of claim 1 , wherein the first layer and the third layer comprise silicon and oxygen.
5. The device of claim 1 , wherein the air gap is in direct contact with the first layer and the third layer.
6. The device of claim 1 , wherein the second layer and the fourth layer comprise a metal or metallic material.
7. The device of claim 1 , further comprising:
a first capping layer disposed above the second layer; and
a second capping layer disposed above the fourth layer.
8. The device of claim 7 , wherein the first capping layer comprises at least one of silicon dioxide and silicon nitride.
9. The device of claim 7 , wherein the first layer and the first capping layer comprise the same material.
10. The device of claim 1 , wherein the film comprises an insulating or dielectric material.
11. The device of claim 10 , wherein the film comprises silicon dioxide.
12. The device of claim 10 , wherein the film comprises a metal oxide.
13. The device of claim 12 , wherein the film comprises a niobium oxide.
14. The device of claim 1 , wherein the first layer comprises a liner, wherein the liner is disposed on a surface of the first layer adjacent to the air gap.
15. The device of claim 1 , wherein the air gap is greater than 35% of a trench, wherein the trench is defined by a space between the first column and the second column.
16. The device of claim 1 , wherein the air gap has a height between about 10 nm and about 500 nm.
17. The device of claim 1 , wherein the air gap has a width between about 5 nm and about 250 nm.
18. The device of claim 1 , wherein the device has a dielectric constant less than about 3.9.
19. The device of claim 1 , wherein the film has a thickness between about 3 nm to about 200 nm.
20. The device of claim 1 , wherein the film has a thickness between about 5 nm to about 50 nm.