Methods for filling a gap feature on a substrate surface and related semiconductor structures

1. A method for filling a gap feature on a substrate surface, the method comprising:

providing a substrate comprising a gap feature into a reaction chamber; and

filling the gap feature with a metal nitride film by performing one or more unit cycles of a cyclical deposition process, wherein a unit cycle of the cyclical deposition process comprises:

contacting the substrate with a metal precursor;

contacting the substrate with a nitrogen precursor to form the metal nitride film; and

after contacting the substrate with the nitrogen precursor, contacting the metal nitride film with a halide growth inhibitor,

wherein the halide growth inhibitor is introduced into the reaction chamber from an external source vessel,

wherein the metal precursor comprises a metal selected from the group consisting of titanium, hafnium, aluminum, gallium, niobium, molybdenum, indium, tantalum, and tungsten, and

wherein the cyclical deposition process comprises a non-conformal deposition process, wherein the non-conformal deposition process deposits the metal nitride film in the gap feature at a distal location from an opening of the gap feature.

2. The method of claim 1 , wherein the metal nitride film comprises at least one of a: titanium nitride film, hafnium nitride film, aluminum nitride film, gallium nitride film, niobium nitride film, molybdenum nitride film, indium nitride film, tantalum nitride film, or a tungsten nitride film.

3. The method of claim 2 , wherein the metal nitride film comprises a titanium nitride film.

4. The method of claim 3 , wherein the titanium nitride film has an average film thickness of between 10 and 30 Å.

5. The method of claim 3 , wherein the titanium nitride film is physically continuous at an average film thickness of less than 10 Å.

6. The method of claim 3 , wherein the titanium nitride film has an average film thickness of less than 60 Å and an electrical resistivity of less than 250 μΩ-cm.

7. The method of claim 3 , wherein the titanium nitride film has atomic-% of halide impurities of less than 1 atomic-%.

8. The method of claim 1 , wherein the metal nitride film fills the gap feature without the formation of a seam.

9. The method of claim 1 , wherein the cyclical deposition process comprises at least one of: an atomic layer deposition process, or a cyclical chemical vapor deposition process.

10. The method of claim 1 , wherein the metal precursor comprises a metal halide precursor.

11. The method of claim 10 , wherein the metal halide precursor comprises a metal chloride precursor.

12. The method of claim 11 , wherein the metal chloride precursor comprises at least one of: titanium tetrachloride (TiCl 4 ), hafnium tetrachloride (HfCl 4 ), aluminum trichloride (AlCl 3 ), NiCl 2 (TMPDA), gallium monochloride (GaCl), gallium trichloride (GaCl 3 ), niobium pentachloride (NbCl 5 ), molybdenum tetrachloride (MoCl 4 ), molybdenum pentachloride (MoCl 5 ), molybdenum (V) trichloride oxide (MoOCl 3 ), molybdenum (VI) tetrachloride oxide (MoOC 4 ), molybdenum (IV) dichloride dioxide (MoO 2 Cl 2 ), indium trichloride (InCl 3 ), tantalum pentachloride (TaCl 5 ), tungsten hexachloride (WCl 6 ).

13. The method of claim 1 , wherein the nitrogen precursor comprises at least one of: molecular nitrogen (N 2 ), hydrazine (N 2 H 4 ), a hydrazine derivative, or a nitrogen-based plasma.

14. The method of claim 1 , wherein a second volume of the halide growth inhibitor is sourced from an internal source within the reaction chamber.

15. The method of claim 1 , wherein a second volume of the halide growth inhibitor is formed in-situ within the reaction chamber.

16. The method of claim 1 , wherein the gap feature is disposed between two surfaces of the substrate, and wherein the metal nitride film is deposited on the two surfaces.

17. The method of claim 1 , wherein the halide growth inhibitor comprises HCl vapor.

18. The method of claim 1 , wherein the non-conformal deposition process is modified to enhance preferential deposition of the metal nitride film at the distal location from the opening of the gap feature by at least increasing a partial pressure of the halide growth inhibitor within the reaction chamber.

19. The method of claim 18 , wherein the partial pressure of the halide growth inhibitor within the reaction chamber is controlled between 1 mTorr and 100 mTorr.

20. The method of claim 1 , wherein the gap feature comprises a vertical gap feature and the non-conformal deposition process preferentially deposits the metal nitride film at a base of the vertical gap feature thereby filling the vertical gap feature with the metal nitride film by means of a bottom-up deposition process.

21. The method of claim 1 , wherein the cyclical deposition process is performed at a deposition temperature between 200° C. and 500° C.

22. The method of claim 1 , further comprising depositing one or more additional film layers over the gap feature prior to filling the gap feature with the metal nitride film.

23. The method of claim 1 , wherein the metal nitride film comprises at least a portion of a metal gate stack, the metal gate stack being disposed over at least a portion of a channel region of a metal-oxide-semiconductor transistor structure.

24. The method of claim 23 , wherein the metal nitride film is cyclically deposited directly in a vertical gap feature comprising both vertical metallic surfaces and horizontal metallic surfaces.

25. A semiconductor device structure including a gap feature filled with a metal nitride film by the method of claim 1 .

26. A method for filling a vertical gap feature on a substrate surface, the method comprising:

providing a substrate comprising a vertical gap feature into a reaction chamber configured for a cyclical deposition process;

depositing a metal nitride film within the vertical gap feature by performing repeated unit cycles of a non-conformal cyclical deposition process, wherein a unit cycle of the non-conformal cyclical deposition process comprises:

contacting the substrate with a metal halide precursor;

contacting the substrate with a nitrogen precursor to form the metal nitride film; and

after contacting the substrate with the nitrogen precursor, contacting the metal nitride film with a halide growth inhibitor; and

filling the vertical gap feature with the metal nitride film;

wherein the halide growth inhibitor is provided from an external source, remote from the reaction chamber, fluidly connected to the reaction chamber, and

wherein the metal halide precursor comprises a metal selected from the group consisting of titanium, hafnium, aluminum, gallium, niobium, molybdenum, indium, tantalum, and tungsten.

27. The method of claim 26 , wherein the non-conformal cyclical deposition process preferentially deposits the metal nitride film proximate to a base region of the vertical gap feature thereby filling the vertical gap feature with the metal nitride film by means of bottom-up deposition process.

28. A method for filling a gap feature on a substrate surface, the method comprising:

providing a substrate comprising a gap feature into a reaction chamber configured for a cyclical deposition process;

depositing a metallic gap-fill film comprising at least one of a metal nitride film, a metal oxide film, a metal carbide film, or metal silicide film, within the gap feature by performing repeated unit cycles of a non-conformal cyclical deposition process, wherein a unit cycle of the non-conformal cyclical deposition process comprises:

contacting the substrate with a metal halide precursor;

contacting the substrate with at least one of a nitrogen precursor, an oxygen precursor, a carbon precursor, or a silicon precursor to form the metallic gap-fill film; and

after contacting the substrate with at least one of a nitrogen precursor, contacting the metallic gap-fill film with a halide growth inhibitor; and

filling the gap feature with the metallic gap-fill film;

wherein the halide growth inhibitor is provided from an external source, remote from the reaction chamber, fluidly connected to the reaction chamber, and

wherein the metal halide precursor comprises a metal selected from the group consisting of titanium, hafnium, aluminum, gallium, niobium, molybdenum, indium, tantalum, and tungsten.

29. The method of claim 28 , wherein the metallic gap-fill film comprises a ternary metal gap-fill film.

30. A semiconductor device structure comprising a gap feature filled with a metal compound film by the method of claim 28 .