Cap structure
The present disclosure relates to semiconductor structures and, more particularly, to a cap structure and methods of manufacture. The structure includes: a gate structure composed of conductive gate material; sidewall spacers on the gate structure, extending above the conductive gate material; and a capping material on the conductive gate material and extending over the sidewall spacers on the gate structure.
1. A structure, comprising:
a gate structure composed of conductive gate material;
sidewall spacers on the gate structure, extending above the conductive gate material;
a first capping material directly on the conductive gate material and comprising a recessed portion between the sidewall spacers on the gate structure; and
a second capping material within the recessed portion of the first capping material and extending over and in direct contact with a top surface of the sidewall spacers on the gate structure.
2. The structure of claim 1 , wherein the second capping material is T-shaped.
3. The structure of claim 2 , wherein the second capping material is a top material that is resistant to etch chemistries and which overhangs over the sidewall spacers.
4. The structure of claim 3 , wherein the top material is SiOC.
5. The structure of claim 3 , wherein the top material overhangs the sidewall spacers and an etch stop material on the sidewall spacers.
6. The structure of claim 3 , wherein the top layer is SiOC and the first capping material is a bottom layer which directly contacts the conductive gate material and is located between the sidewall spacers is a nitride material.
7. The structure of claim 1 , further comprising contacts adjacent to the gate structure, the contacts being separated from the conductive gate material of the gate structure by at least the sidewall spacers and the capping material which overhangs the sidewall spacers.
8. The structure of claim 1 , wherein the second capping material is planar with interlevel dielectric material, and further comprising an etch stop layer on the sidewall spacers, on a side opposing the conductive gate material, the etch stop layer, wherein
the sidewall spacers and a portion of the first capping material being planar with one another,
the recessed portion of the first capping material is below a top surface of the etch stop layer and the sidewall spacers, and
the second capping layer is directly on the top surface of the etch stop layer and the sidewall spacers and directly contacting a sidewall of the interlevel dielectric material.
9. The structure of claim 1 , further comprising:
an etch stop layer in direct contact with the sidewall spacers and extending over source and drain regions of adjacent gate structures, the etch stop layer and the sidewall spacers having coplanar top surfaces; and
an insulator material in direct contact with the etch stop layer over the sidewall spacers and over the source and drain regions, wherein
the recessed portion of the first capping material is below the top surfaces of the etch stop layer and the sidewall spacers, and
the second capping material overhangs and is in direct contact with the top surface of the etch stop layer and has a top surface coplanar with a top surface of the insulator material.
10. A structure, comprising:
a gate structure composed of conductive gate material;
sidewall spacers on the gate structure and having a top surface extending above a top surface of the conductor material;
an etch stop layer on the sidewall spacers, on a side opposing the conductive gate material; and
a T-shaped bilayer cap on the conductive gate material, the T-shaped bilayer cap comprising a first capping material positioned within the sidewall spacers and having a recessed portion lower than a top surface of the sidewall spacers and a second capping material within the recessed portion and further directly contacting and overhanging the sidewall spacers.
11. The structure of claim 10 , wherein the second capping layer is a top material that is resistant to etch chemistries.
12. The structure of claim 11 , wherein the top material overhangs both the sidewall spacers and the etch stop layer.
13. The structure of claim 11 , wherein the top material is composed of SiOC.
14. The structure of claim 13 , wherein the first capping layer is a bottom material of the T-shaped bilayer cap and is located between the sidewalls spacers and is in direct contact with the conductive gate material.
15. The structure of claim 14 , wherein the bottom material is nitride.
16. The structure of claim 10 , further comprising source and drain contacts formed adjacent to the gate structure, and separated from the conductive gate material by at least the sidewall spacers and a top portion of the T-shaped bilayer cap.
17. The structure of claim 16 , wherein the top portion of the T-shaped bilayer cap that separates the conductive gate material from the source and drain contacts is overhanging the sidewall spacers.
18. The structure of claim 16 , wherein the source and drain contacts are separated from the conductive gate material by the etch stop layer on sides of the sidewall spacers.
19. The structure of claim 10 , wherein:
the etch stop layer is in direct contact with the sidewall spacers and extends over source and drain regions of adjacent gate structures,
the etch stop layer and the sidewall spacers have coplanar top surfaces;
the recessed portion of the first capping material is below the top surfaces of the etch stop layer and the sidewall spacers, and
the second capping material overhangs and is in direct contact with the top surface of the etch stop layer.
20. The structure of claim 19 , further comprising an insulator material in direct contact with the etch stop layer over the spacers and the source and drain regions, wherein the second capping material includes a top surface coplanar with a top surface of the insulator material.