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 selectively 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; and
contacting the substrate with the vaporized ruthenium precursor and a reducing gas, wherein the substrate comprises a first, conductive material and a second, less conductive material and ruthenium is preferentially deposited on the first, conductive material compared with deposition on the second, less conductive material.
2. The method of claim 1 wherein the ruthenium-containing precursors is of Formula II:
wherein one or more R 3 -R 8 are selected from H and C 1 -C 6 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 C 1 -C 6 alkyl.
3. The method of claim 2 wherein one, two, or three of R 3 -R 8 are selected from C 1 -C 3 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 any 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 , wherein the reducing gas is introduced 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 to about 100 μmol:1 L.
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.
19. The method of claim 1 , wherein the first, conductive material comprises copper and the second, less conductive material comprises silicon dioxide.
20. The method of claim 1 , wherein a first deposition rate on the first, conductive material is at least twice a second deposition rate on the second, less conductive material.