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. An atomic layer deposition process for depositing an antimony oxide thin film comprising alternately and sequentially contacting a substrate in a reaction chamber with an antimony precursor and an oxygen source, wherein the antimony precursor has the formula SbR x A 3-x , where x is from 1 to 3, each R can be independently selected to be a linear, branched or cyclic, saturated or unsaturated, C1 to C12 alkyl or alkenyl group and A is a ligand comprising alkylamine, halide, amine, silyl or alkyl, wherein the deposition temperature is at or below about 500° C., and wherein the antimony oxide thin film is resistant to etching in HF and will not show notable etching in 1% HF after one minute.
2. 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.
3. The process of claim 1 , wherein the oxygen source is ozone.
4. The process of claim 1 , wherein the oxygen source is not water.
5. The process of claim 1 , wherein the reaction chamber is part of a batch reactor.
6. The process of claim 1 , wherein the reaction chamber is part of a single wafer reactor.
7. The method of claim 1 wherein the antimony oxide thin film serves as a sacrificial layer in semiconductor processing.
8. The method of claim 7 , wherein the antimony oxide thin film is deposited on resist.
9. A method of depositing an antimony oxide layer by atomic layer deposition comprising:
contacting a substrate in a batch reactor with an antimony precursor having the formula SbR x A 3-x , where x is from 1 to 3, each R can be independently selected to be a linear, branched or cyclic, saturated or unsaturated, C1 to C12 alkyl or alkenyl group and A is a ligand comprising alkylamine, halide, amine, silyl or alkyl;
removing excess antimony precursor;
contacting the substrate with ozone; and
removing excess ozone,
wherein the deposition temperature is at or below about 500° C. and wherein the antimony oxide film can withstand selective etching of a second film using 1% HF, 25% H 2 SO 4 , conc. HNO 3 or 2M NaOH.
10. The method of claim 9 , wherein the antimony oxide precursor comprises Sb(N(CH 3 ) 2 ) 3 .
11. A method of forming a structure on a semiconductor substrate in a reaction space comprising:
depositing a first layer comprising a first material on the substrate;
depositing a second layer of antimony oxide on the substrate by an atomic layer deposition process comprising alternately and sequentially contacting the substrate with an antimony precursor and an oxygen source; and
exposing the first and second layer to an etchant simultaneously, such that the first or second layer is etched,
wherein the antimony precursor has the formula SbR x A 3-x , where x is from 1 to 3, each R can be independently selected to be a linear, branched or cyclic, saturated or unsaturated, C1 to C12 alkyl or alkenyl group and A is a ligand comprising alkylamine, halide, amine, silyl or alkyl.
12. The method of claim 11 , wherein the antimony precursor is selected from the group consisting of antimony halides, an antimony alkoxides, and an antimony alkylamines.
13. The method of claim 11 , wherein the second layer of antimony oxide is deposited prior to depositing the first layer comprising a first material.
14. The method of claim 11 , wherein the second layer of antimony oxide is selectively etched relative to the first layer comprising a first material.
15. The method of claim 11 , wherein the second layer comprising antimony oxide is a sacrificial layer.
16. The method of claim 11 , wherein the second layer comprising antimony oxide is an etch stop layer.
17. The method of claim 11 , wherein the first layer comprising a first material is selectively etched relative to the second layer of antimony oxide.
18. The method of claim 17 , wherein etching comprises contacting the first layer comprising a first material with an etchant selected from the group consisting of HF, H 3 PO 4 , KOH and TMAH.