Methods of forming molybdenum-containing films deposited on elemental metal films
Methods of forming molybdenum-containing films are provided. The methods include thermally depositing a first film on a surface of a substrate, for example, at a first temperature less than or equal to about 400° C., and thermally depositing the molybdenum-containing film (second film) on at least a portion of the first film, for example, at a second temperature of greater than about 400° C. The first film can include an elemental metal, for example, tungsten, molybdenum, ruthenium, or cobalt. The second film includes a reaction product of a molybdenum-containing precursor and a reducing agent.
1. A method for forming a molybdenum-containing film, the method comprising:
A. thermally depositing a first film comprising an elemental metal on a surface of a substrate at a first temperature less than or equal to about 400° C., wherein the elemental metal is cobalt; and
B. thermally depositing a second film on at least a portion of the first film at a second temperature of greater than about 400° C., wherein the second film comprises a reaction product of a molybdenum-containing precursor with a reducing agent.
2. The method of claim 1 , wherein the first film has a thickness of greater than or equal to about 2 nm.
3. The method of claim 1 , wherein the thermally depositing the first film comprises delivering a first metal-containing precursor and a co-reactant to the substrate, wherein the first metal-containing precursor is a cobalt-containing precursor.
4. The method of claim 1 , wherein the thermally depositing the second film comprises delivering the molybdenum-containing precursor and the reducing agent to the substrate, wherein the molybdenum-containing precursor is a molybdenum halide or a molybdenum oxyhalide.
5. The method of claim 4 , wherein molybdenum halide is MoCl 5 or MoF 6 , the molybdenum oxyhalide is MoOCl 4 or MoO 2 Cl 2 , the reducing agent is hydrogen or hydrogen plasma, and/or the co-reactant is selected from the group consisting of 1,4-di-trimethylsilyl-2-methyl-cyclohexa-2,5-diene (CHD), 1,4-bis-trimethylsilyl-1,4-dihydropyrazine (DHP), 1-trimethylsilylcyclohexa-2,5-diene, nitrogen plasma, ammonia plasma, oxygen, air, water, ozone, NH 3 , H 2 , hydrazine, alkylhydrazine, and a combination thereof.
6. The method of claim 1 , wherein the first temperature is less than or equal to about 300° C. and/or the second temperature is about 400° C. to about 600° C.
7. The method of claim 1 , wherein the second film is substantially continuous and conformal and/or the second film has a resistivity of less than or equal to about 200 μΩ-cm.
8. The method of claim 1 , wherein the thermally depositing the first film is performed at a pressure of about 0.1 Torr to about 6 Torr and/or wherein the thermally depositing the second film is performed at a pressure of about 1 Torr to about 100 Torr.
9. The method of claim 1 , wherein the first film is thermally deposited by chemical vapor deposition or atomic layer deposition and/or wherein the second film is thermally deposited by chemical vapor deposition or atomic layer deposition.