Atomic layer deposition of antimony oxide films
Antimony oxide thin films are deposited by atomic layer deposition using an antimony reactant and an oxygen source. Antimony reactants may include antimony halides, such as SbCl 3 , antimony alkylamines, and antimony alkoxides, such as Sb(OEt) 3 . The oxygen source may be, for example, ozone. In some embodiments the antimony oxide thin films are deposited in a batch reactor. The antimony oxide thin films may serve, for example, as etch stop layers or sacrificial layers.
1. A vapor deposition process for depositing an antimony oxide thin film comprising alternately and sequentially contacting a substrate in a reaction chamber with a vapor phase antimony source and a vapor phase oxygen source, wherein the antimony oxide thin film can be etched selectively relative to SiO 2 , Si, or Al 2 O 3 in a wet etch comprising concentrated HCl, H 2 O 2 , or tartaric acid, or relative to SiN or SiO 2 in a dry etch comprising Cl-containing plasma, F-containing plasma, Cl 2 -plasma, or a mixture of CHF 3 and Cl 2 -plasma.
2. The process of claim 1 , wherein the antimony oxide has an etch selectivity of at least 75% relative to SiO 2 , Si, or Al 2 O 3 when a wet etch is performed.
3. The process of claim 1 , wherein the antimony oxide has an etch selectivity of at least 50% relative to SiN or SiO 2 when a dry etch is performed.
4. The process of claim 1 , wherein the vapor phase antimony source has the formula Sb(OR) x A 3-x , wherein x is from 1 to 3, each R can be independently selected to be a linear or branched, cyclic or linear, saturated or unsaturated, C1-C12 alkyl or alkenyl group or halogens, amines, or silyls, and wherein A is a ligand comprising alkylamine, halide, amine, silyl, or alkyl.
5. The process of claim 1 , wherein the process is a thermal ALD process.
6. The process of claim 1 , wherein the oxygen source is selected from the group consisting of water, oxygen, hydrogen peroxide, aqueous solution of hydrogen peroxide, ozone, atomic oxygen, oxides of nitrogen, peracids (—O—O—H), alcohols, oxygen-containing radicals and mixtures thereof.
7. The process of claim 1 , wherein the oxygen source comprises ozone.
8. The process of claim 1 , further comprising exposing the substrate to water.
9. The process of claim 8 , wherein the substrate is exposed to water subsequent to contacting the substrate with antimony source and prior to contacting the substrate with the oxygen source.
10. The process of claim 1 , wherein the vapor phase antimony source has the formula SbX z A 3-z , wherein X is a halide, z is from 1 to 3, and A is a ligand comprising alkylamine, a halide different from X, or an amine, silyl, alkoxide or alkyl group and the antimony source has an oxidation state of +III or +V.
11. The process of claim 10 , wherein the vapor phase antimony source is selected from the group consisting of SbCl 3 , SbBr 3 , SbF 3 , or SbI 3 .
12. The process of claim 10 , wherein the vapor phase antimony source comprises Sb(OEt) 3 .
13. The process of claim 1 , wherein the vapor phase antimony source has the formula Sb(NR 2 ) x A 3-x , wherein x is from 1 to 3, wherein each R is independently selected to be linear, branched or cyclic, saturated or unsaturated, C1-C12 alkyl or alkenyl group or hydrogen if the other R is not hydrogen, and wherein A is a ligand comprising alkylamine, halide, amine, silyl or alkyl.
14. The process of claim 13 , wherein the alkyl or alkenyl group is substituted with at least one substituent selected from the group consisting of halogens, amines, and silyls.
15. The process of claim 13 , wherein the vapor phase antimony precursor is selected from the group consisting of Sb(NMe 2 ) 3 , Sb(NEt 2 ) 3 , Sb(NPr 2 ) 3 and Sb(N i Pr 2 ) 3 .
16. The process of claim 1 , wherein the contacting steps comprise a deposition cycle, the process comprising multiple deposition cycles.
17. The process of claim 16 , further comprising repeating the deposition cycle until an antimony oxide film of a desired thickness has been formed.
18. The process of claim 16 , the deposition cycle further comprising removing excess antimony precursor and reaction byproducts, if any, from the substrate subsequent to contacting the substrate with the vapor phase antimony precursor and prior to a subsequent contacting step.
19. The process of claim 16 , the deposition cycle further comprising removing excess oxygen source and reaction byproducts, if any, from the substrate subsequent to contacting the substrate with the oxygen source and prior to a subsequent contacting step.