Integrated circuits with finFET gate structures
Examples of an integrated circuit with FinFET devices and a method for forming the integrated circuit are provided herein. In some examples, an integrated circuit device includes a substrate, a fin extending from the substrate, a gate disposed on a first side of the fin, and a gate spacer disposed alongside the gate. The gate spacer has a first portion extending along the gate that has a first width and a second portion extending above the first gate that has a second width that is greater than the first width. In some such examples, the second portion of the gate spacer includes a gate spacer layer disposed on the gate.
1. A device comprising:
a fin disposed on a substrate, the fin having a first sidewall and an opposing second sidewall and a top surface extending from the first sidewall to the second sidewall, the top surface of the fin facing away from the substrate, wherein the substrate comprises crystalline semiconductor material;
a first gate disposed on the first sidewall of the fin, the first gate including a first gate electrode and a first gate dielectric layer, wherein no portion of the first gate electrode is disposed over the top surface of the fin, wherein the first gate dielectric layer wraps around side and bottom surfaces of the first gate electrode;
a first gate spacer disposed along a first side of the first gate, wherein the first gate spacer has a first portion extending along the first gate and having a first width and a second portion extending above the first gate and having a second width that is different than the first width, wherein the second portion of the first gate spacer extends above a height of at least one of the first gate electrode and the first gate dielectric layer; and
a capping dielectric layer disposed over the first gate and the first gate spacer, wherein the capping dielectric layer interfaces a sidewall and a top surface of the second portion of the first gate spacer.
2. The device of claim 1 , wherein the first portion of the first gate spacer is formed of a first spacer layer and a second spacer layer, and
wherein the second portion of the first gate spacer is formed of the first spacer layer, the second spacer layer and a third spacer layer,
wherein the third spacer layer is disposed on the first gate.
3. The device of claim 2 , wherein the first, second and third spacer layers are formed of different materials from each other.
4. The device of claim 1 , further comprising a second gate disposed on the second sidewall of the fin, the second gate including a second gate electrode and a second gate dielectric layer, wherein no portion of the second gate electrode is disposed over the top surface of the fin.
5. The device of claim 4 , further comprising a conductive cap extending from the first gate electrode to the second gate electrode thereby electrically coupling the first and second gate electrodes, wherein the conductive cap is disposed between the first gate and the capping dielectric layer.
6. The device of claim 1 , further comprising a fin-top hard mask disposed directly on the top surface of the fin.
7. The device of claim 6 , wherein the second portion of the first gate spacer is disposed directly on a top surface of the fin-top hard mask, the top surface of the fin-top hard mask facing away from the substrate.
8. The device of claim 6 , further comprising an etch stop layer disposed directly on the first portion of the first gate spacer, the second portion of the first gate spacer and the fin-top hard mask.
9. A device comprising:
a fin disposed on a substrate, the fin having a first sidewall and an opposing second sidewall and a top surface extending from the first sidewall to the second sidewall, the top surface of the fin facing away from the substrate;
a first gate structure disposed on the first sidewall of the fin, the first gate structure including a first gate electrode and a first gate dielectric layer, wherein no portion of the first gate electrode is disposed over the top surface of the fin;
a second gate structure disposed on the second sidewall of the fin, the second gate structure including a second gate electrode and a second gate dielectric layer, wherein the first gate structure and the second gate structure are spaced apart from one another by the fin along a direction;
a first source/drain feature and a second source/drain feature extending downward into the fin and spaced apart from one another along a second direction perpendicular to the first direction;
a first gate spacer disposed along the first gate structure and the second gate structure, wherein the first gate spacer extends continuously from the first gate dielectric layer to the second gate dielectric layer such that the first gate spacer interfaces with both the first and second gate dielectric layers, wherein an upper portion of the first gate spacer extends above the first gate structure; and
a capping dielectric layer disposed over the first gate structure and the first gate spacer, wherein the capping dielectric layer interfaces a sidewall and a top surface of the upper portion of the first gate spacer.
10. The device of claim 9 , wherein the first gate spacer includes:
a first spacer layer disposed directly on the first gate dielectric layer and the second gate dielectric layer; and
a second spacer layer disposed directly on the first spacer layer, the first gate dielectric layer and the second gate dielectric layer.
11. The device of claim 10 , wherein the first spacer layer has a different material composition than the second spacer layer.
12. The device of claim 10 , wherein the first gate spacer further includes a third spacer layer disposed directly on the second spacer layer, and
wherein the third spacer layer has a different material composition than the second spacer layer.
13. The device of claim 12 , wherein the third spacer layer does not interface with either of the first and second gate dielectric layers.
14. The device of claim 9 , further comprising a contact feature disposed on and interfacing with the first gate spacer.
15. The device of claim 14 , further comprising a second gate spacer disposed along the first gate structure and the second gate structure, wherein the second gate spacer extends continuously from the first gate dielectric layer to the second gate dielectric layer such that the second gate spacer interfaces with both the first and second gate dielectric layers,
wherein the first gate spacer is disposed along respective first sides of the first and second gate structures and the second gate spacer is disposed along respective second sides of the first and second gate structures, the respective first sides of the first and second gate structures being opposite the respective second sides of the first and second gate structures, and
wherein the contact feature includes a first portion extending from the first gate spacer to the second gate spacer and a second portion extending over the first and second gate spacers, the first portion of the contact feature having a first width and the second portion of the contact feature having a second width that is different than the first width.
16. A device comprising:
a fin disposed on a substrate, the fin having a first sidewall and an opposing second sidewall and a top surface extending from the first sidewall to the second sidewall, the top surface of the fin facing away from the substrate;
a first gate structure disposed on the first sidewall of the fin, the first gate structure including a first gate dielectric layer and a first gate electrode layer;
a second gate structure disposed on the second sidewall of the fin, the second gate structure including a second gate dielectric layer and a second gate electrode layer;
a first gate spacer including a first portion disposed along a sidewall surface of the first gate structure, a second portion disposed along a sidewall surface of the second gate structure and a third portion disposed above both the first and second gate structures and over the top surface of the fin, the third portion of the first gate spacer having a different width than at least one of the first or second portions of the first gate spacer;
a conductive cap extending over top surface of the fin from the first gate structure to the second gate structure to electrically couple the first and second gate structures, wherein the third portion of the first gate spacer extends to a greater height above the substrate than the conductive cap; and
a capping dielectric layer disposed over the conductive cap and the first gate spacer, wherein the capping dielectric layer interfaces a sidewall and a top surface of the third portion of the first gate spacer.
17. The device of claim 16 , further comprising an interlayer dielectric layer disposed over the substrate, wherein the interlayer dielectric layer interfaces with the first, second and third portions of the first gate spacer.
18. The device of claim 16 , wherein the first portion of the first gate spacer interfaces with the first gate dielectric layer and wherein the second portion of the first gate spacer interfaces with the second gate dielectric layer.
19. The device of claim 16 , further comprising a top-fin hard mask disposed directly on the top surface of the fin, wherein the conductive cap is disposed directly on the top-fin hard mask such that the conductive cap is prevented from interfacing with the top surface of the fin by the top-fin hard mask.
20. The device of claim 16 , further comprising an etch stop layer disposed along and interfacing with the first, second and third portions of the first gate spacer.