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 vapour-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-stabilised zirconium oxide (YSZ) thin film on a substrate.
1. An atomic layer deposition method for forming a zirconium oxide film on a substrate, comprising:
providing the substrate in a reaction space; and
depositing a zirconium oxide film on the substrate by exposing the substrate in the reaction space to temporally-separated pulses of a zirconium-containing precursor and an oxygen-containing precursor,
wherein the zirconium-containing precursor comprises a plurality of ligands, wherein at least one of the ligands is an amine.
2. The method of claim 1 , wherein at least one of the ligands is selected from the group consisting of a cyclopentadienyl and a cyclopentadienyl derivative.
3. The method of claim 2 , wherein the cyclopentadienyl derivative has the general formula C 5 H 5-y R′″ y , wherein:
R′″ is the hydrocarbon; and
y is an integer between 1 and 5.
4. The method of claim 1 , wherein the zirconium-containing precursor comprises a plurality of amine ligands.
5. The method of claim 1 , wherein the plurality of ligands each comprises a hydrocarbon group selected from the group consisting of a methyl group and an alkyl group.
6. The method of claim 5 , wherein the alkyl group is a linear alkyl group.
7. The method of claim 1 , further comprising maintaining the substrate at a temperature below a decomposition temperature of the zirconium-containing precursor during depositing the zirconium oxide film.
8. The method of claim 7 , wherein depositing the zirconium oxide film is performed at a deposition temperature in a range between 250° C. and 500° C.
9. The method of claim 1 , wherein the oxygen-containing precursor 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.
10. The method of claim 1 , further comprising exposing the substrate to pulses of a yttrium-containing material during depositing the zirconium oxide film to form a yttrium-stabilized zirconium oxide film.
11. The method of claim 1 , wherein each pulse of the zirconium-containing precursor deposits a self-saturated layer of zirconium on the substrate.
12. A method for forming a zirconium oxide film, comprising:
exposing a substrate to a pulse of a zirconium-containing precursor comprising a plurality of ligands to self-limitingly deposit a zirconium-containing layer on the substrate, wherein the plurality of the ligands comprises an amine;
subsequently exposing the zirconium layer to a pulse of an oxygen-containing precursor; and
sequentially repeating exposing the substrate and subsequently exposing the zirconium-containing layer to form a zirconium oxide film of a desired thickness.
13. The method of claim 12 , wherein the plurality of the ligands comprises a cyclopentadienyl or a cyclopentadienyl derivative.
14. The method of claim 13 , wherein the cyclopentadienyl derivative comprises a methyl or alkyl group.
15. The method of claim 12 , wherein amines constitute a plurality of the ligands.
16. The method of claim 15 , wherein the amines are a same amine species.
17. The method of claim 15 , wherein the plurality of the ligands comprises a methyl or alkyl group.
18. The method of claim 12 , further comprising exposing the substrate to pulses of an yttrium-containing material during sequentially repeating exposing the substrate and subsequently exposing the zirconium layer to form a yttrium-stabilized zirconium oxide film.
19. The method of claim 12 , wherein the substrate is a partially fabricated integrated circuit, wherein the zirconium oxide film forms part of a capacitor or a transistor.
20. The method of claim 12 , wherein exposing the substrate and subsequently exposing the zirconium-containing layer are performed below a decomposition temperature of the zirconium-containing precursor.