PROTECTIVE LINER BETWEEN A GATE DIELECTRIC AND A GATE CONTACT
A method of forming a protective liner between a gate dielectric and a gate contact. The method may include; forming a finFET having a replacement metal gate (RMG) on one or more fins, the RMG includes a gate dielectric wrapped around a metal gate, an outer liner is on the sidewalls of the gate dielectric and on the fins; forming a gate contact trench by recessing the gate dielectric and the outer liner below a top surface of the metal gate in a gate contact region; forming a protective trench by further recessing the gate dielectric below a top surface of the outer liner; filling the protective trench with a protective liner; and forming a gate contact in the gate contact trench, where the protective liner is between the gate dielectric and the gate contact.
1 . A semiconductor structure comprising:
a gate comprising a gate dielectric disposed on opposite sidewalls of the gate;
a gate contact above and in electrical contact with the gate;
a protective liner separating the gate dielectric from the gate contact, wherein a lateral thickness of first portions of the protective liner is equal to a lateral thickness of a portion of the gate dielectric; and
a gate contact liner separating the protective liner from the gate contact.
2 . The structure of claim 1 , wherein the top surface of the gate dielectric is below a top surface of the gate.
3 . The structure of claim 1 , further comprising:
a dielectric liner separating portions of the gate dielectric and portions of the protective liner from an interlevel dielectric layer, wherein a top surface of the dielectric liner is below a top surface of the gate and above a top surface of the gate dielectric.
4 . The structure of claim 1 , wherein the gate contact is arranged perpendicular to the gate.
5 . The structure of claim 1 , wherein portions of the gate contact extend below an upper surface of the gate.
6 . The structure of claim 1 , wherein the gate dielectric separates the gate from a fin.
7 . A semiconductor structure comprising:
a replacement metal gate comprising a gate dielectric in direct contact with opposite sidewalls of the replacement metal gate;
a gate contact above and in electrical contact with the replacement metal gate;
a protective liner separating the gate dielectric from the gate contact, wherein first portions of the protective liner are in direct contact with a top surface of the gate dielectric and opposite sidewalls of the replacement metal gate, wherein a lateral thickness of the first portions of the protective liner is equal to a lateral thickness of a portion of the gate dielectric; and
a gate contact liner separating the protective liner from the gate contact.
8 . The structure of claim 7 , wherein the top surface of the gate dielectric is below a top surface of the replacement metal gate.
9 . The structure of claim 7 , further comprising:
a dielectric liner separating portions of the gate dielectric and portions of the protective liner from an interlevel dielectric layer, wherein a top surface of the dielectric liner is below a top surface of the replacement metal gate and above a top surface of the gate dielectric.
10 . The structure of claim 7 , wherein the gate contact is arranged perpendicular to the replacement metal gate.
11 . The structure of claim 7 , wherein portions of the gate contact extend below an upper surface of the replacement metal gate.
12 . The structure of claim 7 , wherein the gate dielectric separates the replacement metal gate from a fin.
13 . A semiconductor structure comprising:
a replacement metal gate comprising a gate dielectric in direct contact with opposite sidewalls and a bottom of the replacement metal gate;
a gate contact above and in electrical contact with the replacement metal gate;
a protective liner separating the gate dielectric from the gate contact, wherein first portions of the protective liner are in direct contact with a top surface of the gate dielectric and opposite sidewalls of the replacement metal gate, wherein a lateral thickness of the portions of the protective liner is equal to a lateral thickness of a portion of the gate dielectric,
wherein second portions of the protective liner are disposed along vertical sidewalls of the gate contact; and
a gate contact liner separating the protective liner from the gate contact.
14 . The structure of claim 13 , wherein the top surface of the gate dielectric is below a top surface of the replacement metal gate.
15 . The structure of claim 13 , further comprising:
a dielectric liner separating portions of the gate dielectric and portions of the protective liner from an interlevel dielectric layer, wherein a top surface of the dielectric liner is below a top surface of the replacement metal gate and above a top surface of the gate dielectric.
16 . The structure of claim 13 , wherein the gate contact is arranged perpendicular to the replacement metal gate.
17 . The structure of claim 13 , wherein portions of the gate contact extend below an upper surface of the replacement metal gate.
18 . The structure of claim 13 , wherein the gate dielectric separates the replacement metal gate from a fin.
19 . The structure of claim 13 , wherein the first portions of the protective liner do not contact the second portions of the protective liner.