FinFETs and methods of forming FinFETs

1. A method comprising:

forming a fin on a substrate;

forming source/drain regions on the fin;

forming a gate structure over the fin, the source/drain regions being on opposing sides of the gate structure;

forming a first mask layer over the gate structure;

forming first conductive contacts over and electrically coupled to the source/drain regions;

recessing the first conductive contacts to form first recesses; and

forming a second mask layer in the first recesses, the first mask layer having a different material composition than the second mask layer.

2. The method of claim 1 , wherein the first mask layer is formed before the second mask layer.

3. The method of claim 1 , wherein the second mask layer is formed before the first mask layer.

4. The method of claim 1 further comprising:

forming a liner insulation layer in the first recesses, the liner insulation layer being interposed between the first conductive contacts and the second mask layer.

5. The method of claim 4 , wherein the liner insulation layer is a metallic oxide or metallic nitride comprising aluminum, titanium, hafnium, zirconium, tantalum, or a combination thereof, and wherein the second mask layer comprises silicon oxynitride, silicon carbide, carbon-containing silicon oxide, or a combination thereof.

6. The method of claim 1 , wherein the first mask layer comprises silicon nitride, and wherein the second mask layer comprises silicon oxynitride, silicon carbide, or a combination thereof.

7. The method of claim 1 further comprising:

forming a second conductive contact through the first mask layer to be coupled to the gate structure; and

forming third conductive contacts through the second mask layer to be electrically coupled to the first conductive contacts.

8. The method of claim 7 , wherein top surfaces second conductive contact and third conductive contacts are level.

9. The method of claim 1 further comprising:

forming a second gate structure over the fin;

forming a dielectric layer surrounding the second gate structure; and

replacing the second gate structure with the gate structure, the gate structure comprising a gate dielectric on the fin and a gate electrode on the gate dielectric.

10. A method comprising:

forming fins on a substrate;

forming an isolation region on the substrate, the isolation region surrounding lower portions of the fins;

forming a first gate structure over the fins;

epitaxially growing source/drain regions on opposing sides of the first gate structure;

forming an inter-layer dielectric over the isolation region and the first gate structure;

replacing the first gate structure with a second gate structure;

recessing the second gate structure to form a first recess;

forming a first mask in the first recess;

forming first conductive contacts through the inter-layer dielectric to the source/drain regions;

recessing the first conductive contacts to form second recesses;

forming a liner insulation layer over the recessed first conductive contacts in the second recesses; and

forming second masks on the liner insulation layer in the second recesses.

11. The method of claim 10 , wherein the first recess is formed before the second recesses.

12. The method of claim 10 , wherein the second recesses are formed before the first recess.

13. The method of claim 10 , wherein the first mask comprises silicon nitride, and wherein the second masks comprise silicon oxynitride, silicon carbide, or a combination thereof.

14. The method of claim 10 further comprising:

forming a second conductive contact through the first mask to be coupled to the first gate structure; and

forming third conductive contacts through the second masks and the liner insulation layer to be electrically coupled to the first conductive contacts.

15. The method of claim 10 , wherein the liner insulation layer is a metallic oxide or metallic nitride comprising aluminum, titanium, hafnium, zirconium, tantalum, or a combination thereof, and wherein the second masks comprise silicon oxynitride, silicon carbide, carbon-containing silicon oxide, or a combination thereof.

16. The method of claim 10 , wherein the material composition of the first mask is different from the material composition of the second masks.

17. A method comprising:

forming a fin over a substrate;

forming an isolation region surrounding lower portions of the fin;

forming a source/drain region on the fin;

forming a dielectric layer over the isolation region and the source/drain region;

forming a gate structure on the fin and the isolation region, the gate structure being adjacent the source/drain region;

forming a first mask over the gate structure, the first mask having a top surface level with a top surface of the dielectric layer;

forming a first conductive contact in the dielectric layer, the first conductive contact contacting the source/drain region; and

forming a second mask over the first conductive contact, the second mask having a top surface level with the top surface of the dielectric layer; and

forming a second conductive contact in the second mask, the second conductive contact electrically coupled to the first conductive contact.

18. The method of claim 17 further comprising:

forming a liner insulation layer interposed between the first conductive contact and the second mask.

19. The method of claim 18 , wherein the second conductive contact extends through the second mask and the liner insulation layer, the second conductive contact electrically coupled to the first conductive contact, a top surface of the second conductive contact being level with the top surface of the dielectric layer.

20. The method of claim 17 , wherein the material composition of the first mask is different from the material composition of the second mask.