Semiconductor device and method
A method includes forming a dummy gate structure over a semiconductor fin, forming a dielectric layer on opposing sides of the dummy gate structure, and removing the dummy gate structure to form a recess in the dielectric layer. The method further includes forming a gate dielectric layer and at least one conductive layer successively over sidewalls and a bottom of the recess, and treating the gate dielectric layer and the at least one conductive layer with a chemical containing fluoride (F).
1. A method comprising:
forming a dummy gate structure over a semiconductor fin;
forming a dielectric layer on opposing sides of the dummy gate structure;
removing the dummy gate structure to form a recess in the dielectric layer;
forming a gate dielectric layer and at least one conductive layer successively over sidewalls and a bottom of the recess; and
treating the gate dielectric layer and the at least one conductive layer with a chemical containing fluoride (F), wherein treating the gate dielectric layer comprises:
forming a fluoride-containing film over the at least one conductive layer; and
driving fluoride in the fluoride-containing film into the gate dielectric layer.
2. The method of claim 1 , wherein the forming the gate dielectric layer and the at least one conductive layer comprises:
forming a gate dielectric layer over the sidewalls and the bottom of the recess;
forming a capping layer over the gate dielectric layer, the capping layer comprising a first conductive material; and
forming a barrier layer over the capping layer, the barrier layer comprising a second conductive material different from the first conductive material.
3. The method of claim 2 , wherein the gate dielectric layer comprise a high-K dielectric material.
4. The method of claim 3 , wherein the capping layer comprises titanium nitride (TiN), and the barrier layer comprises tantalum nitride (TaN).
5. The method of claim 1 , further comprising performing a thermal anneal process after the treating.
6. The method of claim 1 , further comprising filling the recess using a conductive material after the treating.
7. A method of forming a Fin Field-Effect Transistor (FinFET) comprising:
providing a substrate with a fin protruding above upper surfaces of isolation structures disposed on opposing sides of the fin;
forming a first gate structure over the fin;
forming an inter-layer dielectric (ILD) layer around the first gate structure, the ILD layer exposing an upper surface of the first gate structure;
removing the first gate structure to form a recess in the ILD layer;
forming a layer slack in the recess, wherein the forming the layer stack comprises:
conformally forming a high-K dielectric layer in the recess;
conformally forming a conductive capping layer over the high-K dielectric layer; and
conformally forming a conductive barrier layer over the conductive capping layer;
performing a surface treatment process for the layer stack using a chemical comprising fluoride, wherein the surface treatment process drives fluoride into the high-K dielectric layer, wherein performing the surface treatment process comprises:
soaking the layer stack in a fluoride-containing gas or a fluoride-containing plasma; and
depositing a film over the conductive barrier layer after the making using a fluoride-containing precursor; and
performing a thermal anneal process after the surface treatment process.
8. The method of claim 7 , further comprising:
removing the film after the thermal anneal process; and
filling the recess with a conductive material.
9. A method comprising:
forming a dielectric layer;
covering the dielectric layer with at least one conductive layer;
supplying a fluoride-containing precursor over the at least one conductive layer, wherein the supplying deposits a film over the at least one conductive layer; and
driving fluoride of the fluoride-containing precursor into the dielectric layer.
10. The method of claim 9 , wherein the fluoride-containing precursor is a fluoride-containing gas or a fluoride-containing plasma.
11. The method of claim 9 , wherein the dielectric layer comprises a high-K dielectric material, and wherein the driving comprises at least a thermal drive-in process.
12. The method of claim 1 , wherein forming the fluoride-containing film comprises forming the fluoride-containing film using a fluoride-containing precursor.
13. The method of claim 12 , wherein the fluoride-containing precursor comprises molybdenum hexafluoride (MoF 6 ).
14. The method of claim 12 , wherein fluoride in the fluoride-containing film is driven into the gate dielectric layer but not into the dielectric layer.
15. The method of claim 1 , further comprising, after treating the gate dielectric layer, removing the fluoride-containing film.
16. The method of claim 9 , further comprising removing the film after the driving.
17. The method of claim 9 , where the supplying comprises soaking the at least one conductive layer in a gas comprising tungsten hexafluoride (WF 6 ).
18. The method of claim 9 , where the supplying comprises treating the at least one conductive layer with a plasma process using nitrogen trifluoride (NF 3 ).
19. The method of claim 7 , further comprising removing the film after performing the thermal anneal process.
20. The method of claim 7 , further comprising after performing the thermal anneal process, forming a conductive material directly on the film.