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-containing thin film on a substrate comprising a plurality of deposition cycles in which the substrate is alternately and sequentially contacted with a first reactant that comprises TiCl 4 and a second reactant comprising triethylaluminum (TEA), wherein in at least one of the deposition cycles the substrate is contacted with a third reactant selected from the group consisting of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes, germanium compounds, nitrogen compounds, boron compounds and boranes.
2. The process of claim 1 , wherein the substrate is contacted with the third reactant in each of the plurality of deposition cycles.
3. The process of claim 1 , wherein the third reactant is an alkane, alkene or alkyne.
4. The process of claim 3 , wherein the third reactant is acetylene.
5. The process of claim 1 , wherein the third reactant is a silane or borane.
6. The process of claim 1 , wherein at least one deposition cycle comprises:
contacting the substrate with TiCl 4 ;
removing excess TiCl 4 from the reaction space;
contacting the substrate with TEA;
removing excess TEA from the reaction space.
7. The process of claim 1 , wherein the plurality of deposition cycles is carried out at a reaction temperature from about 350° C. to about 450° C.
8. 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 alternate, sequential pulses of TiCl 4 and triethylaluminum (TEA), wherein subsequent to at least one ALD cycle, the substrate is contacted with a third reactant that is capable of removing halide ligands from the substrate surface or the reaction space.
9. The method of claim 8 , wherein the ALD cycle is repeated multiple times prior to contacting the substrate with the third reactant.
10. The method of claim 8 , wherein the third reactant comprises one or more of hydrocarbons, hydrogen, hydrogen plasma, hydrogen radicals, silanes, germanium compounds, nitrogen compounds, and boron compounds.
11. The method of claim 8 , wherein the third reactant comprises a silane or borane.
12. The method of claim 8 , wherein the third reactant is acetylene.
13. The method of claim 8 , wherein the third reactant comprises hydrogen radicals.
14. The method of claim 8 , wherein the substrate is contacted with hydrogen radicals at one or more intervals while carrying out the one or more ALD cycles.