ALD of zirconium-containing films using cyclopentadienyl compounds
Atomic layer deposition (ALD) type processes for producing metal containing thin films comprise feeding into a reaction space vapor phase pulses of metal containing cyclopentadienyl precursors as a metal source material, wherein the metal is zirconium. In preferred embodiments the metal containing cyclopentadienyl reactant comprises a metal atom that is not directly bonded to an oxygen or halide atom. In other embodiments the metal atom is bonded to a cyclopentadienyl compound and separately bonded to at least one ligand via a nitrogen atom. In still other embodiments the metal containing cyclopentadienyl compound comprises a nitrogen-bridged ligand.
1. A plasma enhanced atomic layer deposition process for producing a metal containing thin film on a substrate comprising alternately and sequentially contacting the substrate with vapor phase pulses of at least one volatile metal containing cyclopentadienyl compound, and a second reactant at a temperature that is low enough to prevent decomposition of the metal containing cyclopentadienyl compound and the second reactant, wherein the metal comprises zirconium, and wherein the metal containing cyclopentadienyl compound does not contain a metal directly bonded to a halide or oxygen atom, and wherein the metal containing cyclopentadienyl compound comprises at least one cyclopentadienyl bonded to the metal and at least one ligand that is separately bonded to the metal via nitrogen.
2. The process of claim 1 , wherein the metal containing cyclopentadienyl compound has the formula: (R 1 R 2 R 3 R 4 R 5 Cp) x -MR 0 z —(NR 1 R 2 ) y
wherein M is zirconium;
wherein each R 1 , R 2 , R 3 , R 4 , R 5 , and R 0 is independently selected from:
(i) hydrogen;
(ii) linear and branched C 1 -C 20 alkyl, alkenyl and alkynyl groups, which are independently substituted or unsubstituted;
(iii) carbocyclic groups, such as aryl, phenyl, cyclopentadienyl, alkylaryl, and halogenated carbocyclic groups; and
(iv) heterocyclic groups; and
wherein both x and y are ≧1 and z ≧0.
3. The process of claim 2 , wherein each of the R 1 and R 2 is independently selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, t-butyl, n-amyl, isoamyl, n-pentyl, isopentyl, n-hexyl, isohexyl, and 2,3-dimethyl-2-butyl.
4. The process of claim 2 , wherein each of the R 1 and R 2 is independently selected from linear and branched C 1 -C 4 alkyl, alkenyl, and alkynyl groups, which are independently substituted or unsubstituted.
5. The process of claim 4 , wherein each of the R 1 and R 2 is independently selected from linear and branched C 1 -C 4 alkyl, which are independently substituted or unsubstituted.
6. The process of claim 2 , wherein z is 0.
7. The process of claim 6 , wherein y is 3.
8. The process of claim 1 , wherein the metal containing cyclopentadienyl compound does not comprise halide or oxygen atoms.
9. The process of claim 1 , wherein the metal containing thin film comprises an insulator material.
10. The process of claim 1 , wherein the temperature is 200° C. to 400° C.
11. An atomic layer deposition process for producing a metal containing thin film on a substrate comprising sequentially:
contacting the substrate with a vapor pulse of a first reactant, wherein the first reactant comprises a metal containing cyclopentadienyl compound, wherein the metal containing cyclopentadienyl compound does not contain a metal directly bonded to a halide or oxygen atom, and wherein the metal containing cyclopentadienyl compound has the formula: (R 1 R 2 R 3 R 4 R 5 Cp) x —MR 0 z—(NR 1 R 2 ) y
wherein M is zirconium;
wherein each R l , R 2 , R 3 , R 4 , R 5 , and R is independently selected from:
(i) hydrogen,
(ii) linear and branched C 1 -C 20 alkyl, alkenyl and alkynyl groups, which are independently substituted or unsubstituted, and
wherein both x and y are ≧1 and z ≧0; and
contacting the substrate with a second reactant.
12. The process of claim 11 , wherein an inert gas serves as a carrier gas for the first reactant.
13. The process of claim 11 , wherein the atomic layer deposition process comprises a plasma enhanced atomic layer deposition process.
14. The process of claim 11 , wherein each of the R 1 and R 2 is independently selected from linear and branched C 1 -C 4 alkyl, alkenyl, and alkynyl groups, which are independently substituted or unsubstituted.
15. The process of claim 14 , wherein each of the R 1 and R 2 is independently selected from linear and branched C 1 -C 4 alkyl, which are independently substituted or unsubstituted.
16. The process of claim 15 , wherein each of the R 1 and R 2 is independently selected from methyl, ethyl, n-propyl, i-propyl, n-butyl, i-butyl, and t-butyl.
17. The process of claim 11 , wherein z is 0.
18. The process of claim 17 , wherein y is 3.
19. The process of claim 11 , wherein the metal containing cyclopentadienyl compound does not comprise halide or oxygen atoms.
20. The process of claim 11 , wherein the metal containing cyclopentadienyl compound comprises a modified cyclopentadienyl group.
21. The process of claim 20 , wherein the modified cyclopentadienyl group is selected from the group consisting of Me 5 Cp, MeCp, EtCp, and Me 3 SiCp.
22. The process of claim 11 , wherein the metal containing thin film comprises an insulating thin film.