Capping structures in semiconductor devices
A semiconductor device and methods of fabricating the same are disclosed. The method can include forming a fin structure on a substrate, forming a source/drain (S/D) region on the fin structure, forming a gate structure on the fin structure adjacent to the S/D region, and forming a capping structure on the gate structure. The forming the capping structure includes forming a conductive cap on the gate structure, forming a cap liner on the conductive cap, and forming a carbon-based cap on the cap liner. The method further includes forming a first contact structure on the S/D region, forming an insulating cap on the first contact structure, and forming a second contact structure on the conductive cap.
1. A method, comprising:
forming a fin structure on a substrate;
forming a source/drain (S/D) region on the fin structure;
forming a gate structure on the fin structure adjacent to the S/D region;
forming a capping structure on the gate structure, wherein the forming the capping structure comprises:
forming a conductive cap on the gate structure,
forming a cap liner on the conductive cap, and
forming a carbon-based cap on the cap liner;
forming a first contact structure on the S/D region;
forming an insulating cap on the first contact structure; and
forming a second contact structure on the conductive cap.
2. The method of claim 1 , wherein the forming the conductive cap comprises etching a portion of the gate structure.
3. The method of claim 1 , wherein the forming the cap liner comprises depositing a nitride layer on the conductive cap.
4. The method of claim 1 , wherein the forming the carbon-based cap comprises depositing a carbide layer on the cap liner.
5. The method of claim 1 , wherein the forming the carbon-based cap comprises depositing a carbide layer with a carbon atom concentration ranging from about 30 atomic % to about 50 atomic %.
6. The method of claim 1 , wherein the forming the carbon-based cap comprises depositing a material comprising carbon and oxygen atoms or carbon and nitrogen atoms, and
wherein a concentration of the carbon atoms is greater than a concentration of the oxygen atoms and a concentration of the nitrogen atoms.
7. The method of claim 1 , wherein the forming the carbon-based cap comprises depositing a carbon-based material with an etch selectivity higher than an etch selectivity of a material of the insulating cap.
8. The method of claim 1 , wherein the forming the carbon-based cap comprises depositing a carbide layer with an etch selectivity about 40 times to about 70 times higher than an etch selectivity of a material of the insulating cap.
9. The method of claim 1 , wherein the forming the insulating cap comprises etching a portion of the first contact structure.
10. The method of claim 1 , wherein the forming the insulating cap comprises depositing a nitride layer, an oxide layer, or an oxynitride layer.
11. A method, comprising:
forming a fin structure on a substrate;
forming a source/drain (S/D) region on the fin structure;
forming a gate structure on the fin structure adjacent to the S/D region;
forming a first contact structure on the S/D region;
forming a first capping structure on the first contact structure, wherein the forming the first capping structure comprises:
forming a cap liner on the first contact structure, and
forming a carbon-based cap on the cap liner;
forming a second capping structure on the gate structure, wherein the forming the second capping structure comprises:
forming a conductive cap on the gate structure, and
forming an insulating cap on the conductive cap; and
forming a second contact structure on the conductive cap.
12. The method of claim 11 , wherein the forming the first capping structure further comprises etching a portion of the first contact structure.
13. The method of claim 11 , wherein the forming the cap liner comprises depositing a nitride layer on the first contact structure.
14. The method of claim 11 , wherein the forming the carbon-based cap comprises depositing a carbon-based material with an etch selectivity higher than an etch selectivity of a material of the insulating cap.
15. The method of claim 11 , further comprising forming a via through the first capping structure on the first contact structure.
16. The method of claim 11 , wherein the forming the second contact structure comprises forming a contact opening through the insulating cap on the conductive cap.
17. A semiconductor device, comprising:
a substrate;
a fin structure disposed on a substrate;
a source/drain (S/D) region disposed on the fin structure;
a gate structure disposed on the fin structure adjacent to the S/D region;
a gate capping structure disposed on the gate structure, wherein the gate capping structure comprises:
a conductive cap disposed on the gate structure,
a cap liner disposed on the conductive cap, and
a carbon-based cap disposed on the cap liner;
a first contact structure disposed on the S/D region;
an insulating cap disposed on the first contact structure; and
a second contact structure disposed on the conductive cap.
18. The semiconductor device of claim 17 , wherein the carbon-based cap comprises a carbide layer with a carbon atom concentration ranging from about 30 atomic % to about 50 atomic %.
19. The semiconductor device of claim 17 , wherein the cap liner comprises a nitride layer.
20. The semiconductor device of claim 17 , wherein the insulating cap comprises a nitride layer, an oxide layer, or an oxynitride layer.