Process for producing zirconium oxide thin films
This invention concerns a process for producing oxide thin film on a substrate by an ALD type process. According to the process, alternating vapor-phase pulses of at least one metal source material, and at least one oxygen source material are fed into a reaction space and contacted with the substrate. According to the invention, an yttrium source material and a zirconium source material are alternately used as the metal source material so as to form an yttrium-stabilized zirconium oxide (YSZ) thin film on a substrate.
1. An atomic layer deposition method for forming a film on a substrate, comprising:
providing the substrate in a reaction space;
depositing a zirconium oxide film on the substrate by exposing the substrate in the reaction space to temporally separated pulses of a zirconium-containing material and an oxygen-containing material, wherein the zirconium source material comprises a ligand selected from the group consisting of a cyclopentadienyl and a cyclopentadienyl derivative; and
maintaining the substrate at a temperature below a decomposition temperature of the zirconium-containing material during depositing the zirconium oxide film.
2. The method of claim 1 , wherein the zirconium-containing material comprises two or more ligands selected from the group consisting of a cyclopentadienyl and a cyclopentadienyl derivative.
3. The method of claim 2 , wherein the zirconium-containing material comprises zirconium with R and X groups as ligands, wherein
R is selected from the group consisting of a cyclopentadienyl and a cyclopentadienyl derivative; and
X is selected from the group consisting of F, Cl, Br, I, H, a linear alkyl group, a branched alkyl group, a linear alkoxide, a branched alkoxide, an amine and an acetate.
4. The method of claim 3 , wherein the linear or branched alkyl groups comprise a 1-10 carbon hydrocarbon chain.
5. The method of claim 3 , wherein the linear alkoxide is a methoxy group.
6. The method of claim 3 , wherein the linear alkyl group is a methyl group.
7. The method of claim 3 , wherein the zirconium-containing material comprises two different X groups.
8. The method of claim 7 , wherein a first X group is a methyl group and a second X group is a methoxy group.
9. The method of claim 3 , wherein the ligands R are bridged together.
10. The method of claim 9 , wherein the ligands R are bridged together with a bridge selected from the group consisting of a methyl group, an alkyl group, and a substituted hydrocarbon.
11. The method of claim 3 , wherein the cyclopentadienyl derivative has the general formula C 5 H 5-y R′″ y , wherein
R′″ is selected from the group consisting of a linear alkyl group, a branched alkyl group, an alkoxy group, an aryl group, an amino group, a cyano group, and a silyl group; and
y is an integer between 1 and 5.
12. The method of claim 11 , wherein the linear or branched alkyl groups comprise a 1-10 carbon hydrocarbon chain.
13. The method of claim 11 , wherein the linear alkyl group is a methyl group.
14. The method of claim 3 , wherein the cyclopentadienyl derivative comprises a ligand R′″, wherein R′″ is selected from the group consisting of a linear alkyl or a branched alkyl group.
15. The method of claim 14 , wherein the linear alkyl group is a methyl group.
16. The method of claim 1 , wherein the oxygen-containing material comprises O 3 .
17. The method of claim 1 , wherein the oxygen-containing material comprises H 2 O.
18. The method of claim 1 , wherein the oxygen-containing material is one or more precursors selected from the group consisting of an oxide of nitrogen, a halide-oxygen compound, a peracid, an alkoxide, an alcohol and an oxygen-containing radical.
19. The method of claim 18 , wherein the oxygen-containing radical is an oxygen radical or a hydroxyl radical.
20. The method of claim 1 , wherein depositing the zirconium oxide film is performed at a deposition temperature in a range between 250 and 500° C.
21. The method of claim 20 , wherein depositing the zirconium oxide film is performed at a deposition temperature in a range between 275° C. and 325° C.
22. The method of claim 1 , further comprising exposing the substrate to pulses of a yttrium-containing material to form a yttrium-stabilized zirconium oxide film.
23. The method of the claim 22 , wherein exposing the substrate in the reaction space to temporally separated pulses of the zirconium-containing material, the oxygen-containing material and the yttrium-containing material constitute a cycle, further comprising performing a plurality of cycles.