Enhanced thin film deposition
Methods of producing metal-containing thin films with low impurity contents on a substrate by atomic layer deposition (ALD) are provided. The methods preferably comprise contacting a substrate with alternating and sequential pulses of a metal source chemical, a second source chemical and a deposition enhancing agent. The deposition enhancing agent is preferably selected from the group consisting of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes, germanium compounds, nitrogen compounds, and boron compounds. In some embodiments, the deposition-enhancing agent reacts with halide contaminants in the growing thin film, improving film properties.
1. An atomic layer deposition (ALD) process for forming a metal carbide thin film comprising a plurality of deposition cycles, at least one cycle comprising contacting a substrate in a reaction space with alternating and sequential pulses of a first reactant that comprises a metal that is to be included in the thin film, a second reactant comprising aluminum and carbon, and a third reactant comprising a silane or borane.
2. The process of claim 1 , wherein the third reactant is provided in each of the plurality of deposition cycles.
3. The process of claim 1 , wherein the third reactant is not provided in each of the plurality of deposition cycles.
4. The method of claim 1 , wherein the third reactant comprises disilane.
5. The process of claim 1 , wherein the first reactant comprises a metal selected from the group consisting of Ti and Nb.
6. The process of claim 1 , wherein the first reactant comprises at least one halide ligand.
7. The process of claim 6 , wherein the first reactant is selected from the group consisting of TiCl 4 and NbCl 5 .
8. The process of claim 1 , wherein the second reactant comprises at least one organic ligand.
9. The process of claim 8 , wherein the second reactant comprises at least one alkyl ligand selected from the group consisting of methyl and ethyl groups.
10. The process of claim 9 , wherein the second reactant comprises trimethylaluminum (TMA) or triethylaluminum (TEA).
11. The process of claim 1 , wherein the first reactant is a Ti or Nb compound, the second source chemical is an Al compound and the third reactant is a silane or borane.
12. The process of claim 11 , wherein the first reactant comprises Ti, the second reactant comprises TMA or TEA and the third reactant comprises a silane.
13. The process of claim 1 , wherein the first reactant is TiCl 4 , the second reactant is TEA and the third reactant is a silane.
14. The process of claim 1 , wherein the at least one deposition cycle comprises:
contacting the substrate with a Ti or Nb halide;
removing excess Ti or Nb halide from the reaction space;
contacting the substrate with an organometallic or metalorganic Al compound;
removing excess organometallic or metalorganic Al compound from the reaction space; and
contacting the substrate with a silane or borane compound.
15. The process of claim 1 , wherein the at least one deposition cycle comprises:
contacting the substrate with a Ti or Nb halide;
removing excess Ti or Nb halide from the reaction space;
contacting the substrate with a silane or borane compound;
removing excess silane or borane compound;
contacting the substrate with an organometallic or metalorganic Al compound; and
removing excess organometallic or metalorganic Al compound from the reaction space.
16. A method for depositing a thin film on a substrate in a reaction chamber, the method comprising:
carrying out one or more atomic layer deposition (ALD) cycles, each ALD cycle comprising contacting the substrate with separate, sequential pulses of a first metal source chemical comprising Ti or Nb, and a second source chemical comprising aluminum; and
subsequent to at least ALD cycle, contacting the substrate with a third reactant comprising a silane or borane.
17. The method of claim 16 , wherein the metal source chemical is a halide compound.
18. The method of claim 17 , wherein the first metal source chemical is TiCl 4 or NbCl 5 .
19. The method of claim 16 , wherein the second source chemical comprises trimethylaluminum (TMA) or triethylaluminum (TEA).
20. The method of claim 16 , wherein the third reactant is disilane.
21. The method of claim 16 , wherein the substrate is contacted with the third reactant after each ALD cycle.
22. The method of claim 16 , wherein the ALD cycle is repeated multiple times prior to contacting the substrate with the third reactant.