Replacement metal gate structures
Replacement metal gate structures with improved chamfered workfunction metal and self-aligned contact and methods of manufacture are provided. The method includes forming a replacement metal gate structure in a dielectric material. The replacement metal gate structure is formed with a lower spacer and an upper spacer above the lower spacer. The upper spacer having material is different than material of the lower spacer. The method further includes forming a self-aligned contact adjacent to the replacement metal gate structure by patterning an opening within the dielectric material and filling the opening with contact material. The upper spacer prevents shorting with the contact material.
1. A structure, comprising:
a plurality of gate structures composed of a gate dielectric with a bottom surface which directly contacts a semiconductor layer, spacers and a bottom surface of chamfered spacers over a top surface of the spacers, the chamfered spacers comprising a chamfered side; and
a contact between the gate structures,
wherein the bottom surface of the gate dielectric is at a same level as a bottom surface of the spacers,
the contact comprises a conductive material in direct contact with sides of the spacers and in direct contact with the chamfered side of the chamfered spacers,
a contact cap with a bottom surface in direct contact with a top surface of a metal material of the gate structure,
the chamfered spacers in direct contact with the metal material, and
an oxide material with a bottom surface in direct contact with a top surface of the contact cap and sides of the conductive material.
2. The structure of claim 1 , wherein the spacers are comprised of a first material.
3. The structure of claim 2 , wherein the chamfered spacers are comprised of a second material.
4. The structure of claim 3 , wherein the first material is different than the second material.
5. The structure of claim 1 , wherein the contact is a self-aligned contact.
6. The structure of claim 5 , wherein the self-aligned contact is composed of a conductive material which is directly on the chamfered spacers.
7. The structure of claim 6 , wherein the gate structures are further composed of a workfunction metal which includes a seam.
8. The structure of claim 7 , wherein the gate structures are further composed of the metal material that plugs the seam.
9. The structure of claim 1 , wherein the workfunction metal is below the chamfered spacers.
10. The structure of claim 1 , wherein the gate structures are further composed of a workfunction metal over the semiconductor layer.
11. The structure of claim 10 , wherein the contact cap is over the workfunction metal.
12. The structure of claim 11 , wherein the workfunction metal includes a seam with a plug comprising the metal material.
13. The structure of claim 12 , wherein the contact cap is directly over a top surface of the plug within the seam.
14. The structure of claim 1 , wherein the oxide material is directly on a top surface of the gate dielectric.
15. The structure of claim 14 , wherein the conductive material is in direct contact with sides of the oxide material.
16. The structure of claim 15 , wherein the bottom surface of the gate dielectric and the bottom surface of the spacers is directly on a top surface of a substrate.
17. The structure of claim 1 , wherein the bottom surface of the contact directly contacts a top surface of the semiconductor layer.
18. The structure of claim 17 , wherein the bottom surface of the oxide material directly contacts a top surface of an interlevel dielectric material.
19. The structure of claim 18 , wherein the interlevel dielectric material directly contacts the top surface of the semiconductor layer, and the semiconductor layer comprises fin structures.
20. The structure of claim 19 , wherein a top surface of the oxide material is at a same level as a top surface of the contact.