Chemical vapor deposition processes using ruthenium precursor and reducing gas
Chemical vapor deposition (CVD) processes which use a ruthenium precursor of formula R 1 R 2 Ru(0), wherein R 1 is an aryl group-containing ligand, and R 2 is a diene group-containing ligand and a reducing gas a described. The CVD can include oxygen after an initial deposition period using the ruthenium precursor and reducing gas. The method can provide selective Ru deposition on conductive materials while minimizing deposition on non-conductive or less conductive materials. Further, the subsequent use of oxygen can significantly improve deposition rate while minimizing or eliminating oxidative damage of the substrate material. The method can be used to form Ru-containing layers on integrated circuits and other microelectronic devices.
1. A method for depositing ruthenium on a substrate in a chemical vapor deposition process comprising:
vaporizing a ruthenium precursor of the Formula I: R 1 R 2 Ru(0), wherein R 1 is an aryl group-containing ligand, and R 2 is a diene group-containing ligand;
contacting a substrate with the vaporized ruthenium precursor and a reducing gas without oxygen, wherein ruthenium is deposited on the substrate; and
contacting the substrate with a mixture of the vaporized ruthenium precursor, the reducing gas, and oxygen, wherein ruthenium is deposited on the substrate.
2. The method of claim 1 wherein the ruthenium-containing precursor is of Formula II:
wherein one or more or R 3 -R 8 are selected from H and C1-C6 alkyl, R 9 is 0 (covalent bond) or a divalent alkene group of 1-4 carbon atoms, and R 10 and R 11 form one or more ring structures or are selected from H and C1-C6 alkyl.
3. The method of claim 2 wherein one, two, or three of R 3 -R 8 are selected from C1-C3 alkyl, with the remaining R 3 -R 8 being H.
4. The method of claim 2 wherein R 9 is 0 (covalent bond), and R 10 and R 11 form one or more ring structures.
5. The method of claim 1 , wherein the ruthenium precursor has a total carbon atom amount in the range of 12 to 20.
6. The method of claim 1 , wherein the ruthenium precursor has a total hydrogen atom amount in the range of 16 to 28.
7. The method of claim 1 , wherein R 1 is benzene or a mono-, di-, or tri-alkylbenzene.
8. The method of claim 1 wherein R 2 is a cyclic diene.
9. The method of claim 1 wherein R 2 is a conjugated diene.
10. The method of claim 1 wherein R 2 is cyclohexadiene or an alkylcyclohexadiene.
11. The method of claim 1 , wherein the rhenium precursor is selected from the group consisting of (cymene)(1,3-cyclohexadiene)Ru(0), (cymene)(1,4-cyclohexadiene)Ru(0), (cymene)(1-methylcyclohexa-1,3-diene)Ru(0), (cymene)(2-methylcyclohexa-1,3-diene)Ru(0), (cymene)(3-methylcyclohexa-1,3-diene)Ru(0), (cymene)(4-methylcyclohexa-1,3-diene)Ru(0), (cymene)(5-methylcyclohexa-1,3-diene)Ru(0), (cymene)(6-methylcyclohexa-1,3-diene)Ru(0), (cymene)(1-methylcyclohexa-1,4-diene)Ru(0), (cymene)(2-methylcyclohexa-1,4-diene)Ru(0), (cymene)(3-methylcyclohexa-1,4-diene)Ru(0), (cymene)(4-methylcyclohexa-1,4-diene)Ru(0), (cymene)(5-methylcyclohexa-1,4-diene)Ru(0), and (cymene)(6-methylcyclohexa-1,4-diene)Ru(0).
12. The method of claim 1 , wherein the rhenium precursor is selected from the group consisting of (benzene)(1,3-cyclohexadiene)Ru(0), (toluene)(1,3-cyclohexadiene)Ru(0), (ethylbenzene)(1,3-cyclohexadiene)Ru(0), (1,2-xylene)(1,3-cyclohexadiene)Ru(0), (1,3-xylene)(1,3-cyclohexadiene)Ru(0), (1,4-xylene)(1,3-cyclohexadiene)Ru(0), (p-cymene)(1,3-cyclohexadiene)Ru(0), (o-cymene)(1,3-cyclohexadiene)Ru(0), (m-cymene)(1,3-cyclohexadiene)Ru(0), (cumene)(1,3-cyclohexadiene)Ru(0), (n-propylbenzene)(1,3-cyclohexadiene)Ru(0), (m-ethyltoluene)(1,3-cyclohexadiene)Ru(0), (p-ethyltoluene)(1,3-cyclohexadiene)Ru(0), (o-ethyltoluene)(1,3-cyclohexadiene)Ru(0), (1,3,5-trimethylbenzene)(1,3-cyclohexadiene)Ru(0), (1,2,3-trimethylbenzene)(1,3-cyclohexadiene)Ru(0), (tert-butylbenzene)(1,3-cyclohexadiene)Ru(0), (isobutylbenzene)(1,3-cyclohexadiene)Ru(0), (sec-butylbenzene)(1,3-cyclohexadiene)Ru(0), (indane)(1,3-cyclohexadiene)Ru(0), (1,2-diethylbenzene)(1,3-cyclohexadiene)Ru(0), (1,3-diethylbenzene)(1,3-cyclohexadiene)Ru(0), (1,4-diethylbenzene)(1,3-cyclohexadiene)Ru(0), (1-methyl-4-propylbenzene)(1,3-cyclohexadiene)Ru(0), and (1,4-dimethyl-2-ethylbenzene)(1,3-cyclohexadiene)Ru(0).
13. The method of claim 1 the reducing gas is introduced is mixture with the vaporized ruthenium precursor.
14. The method of claim 1 wherein the reducing gas is introduced at least prior to introduction of the vaporized ruthenium precursor.
15. The method of claim 1 wherein the step of contacting the ruthenium precursor and the reducing gas are present in combination in an amount in the range of about 1 μmol:1 L, respectively.
16. The method of claim 1 wherein the reducing gas comprises hydrogen, ammonia, or a mixture thereof.
17. The method of claim 1 wherein the step of contacting is carried out at a temperature in the range of 150-400° C.
18. The method of claim 1 wherein the step of contacting is carried out at a pressure in the range of about 0.5 to about 80 Torr.