Solid precursor delivery method using liquid solvent for thin film deposition

Patent metadata

Field	Value
Publication number	US-9869018-B2
Application number	US-201615138473-A
Country	US
Kind code	B2
Filing date	Apr 26, 2016
Priority date	Apr 26, 2016
Publication date	Jan 16, 2018
Grant date	Jan 16, 2018

Abstract

A method of solid precursor delivery for a vapor deposition process is provided. In some embodiments, a precursor ampoule is provided including a solid precursor arranged in the precursor ampoule. A solvent is added to the precursor ampoule including one or more ionic liquids to dissolve chemical species of the solid precursor and to form a liquid precursor. A carrier gas is applied into the liquid precursor through an inlet of the precursor ampoule. A gas precursor is generated at an upper region of the precursor ampoule by vaporization of the liquid precursor. The chemical species of the solid precursor are delivered into a vapor deposition chamber by the carrier gas. The chemical species of the solid precursor is deposited onto a substrate within the vapor deposition chamber.

First claim

What is claimed is:

1. A method of solid precursor delivery for a vapor deposition process, comprising:
providing a precursor ampoule including a solid precursor arranged in the precursor ampoule;
adding a solvent including one or more ionic liquids to the precursor ampoule to partially dissolve chemical species of the solid precursor to form a liquid precursor while leaving an undissolved portion of the solid precursor dispersed in the precursor ampoule;
applying a carrier gas into the liquid precursor through an inlet of the precursor ampoule;
generating a gas precursor including the partially dissolved chemical species at an upper region of the precursor ampoule by vaporization of the liquid precursor, wherein the undissolved portion of the solid precursor decreases as the vaporization continues;
carrying the gas precursor to a vapor deposition chamber by the carrier gas through an outlet of the precursor ampoule, wherein the chemical species of the solid precursor are delivered into the vapor deposition chamber; and
depositing the chemical species of the solid precursor onto a substrate within the vapor deposition chamber.

2. The method of claim 1 , wherein the carrier gas is led into a diffuser immersed into the liquid precursor, and is led out through a plurality of holes of the diffuser into the liquid precursor.

3. The method of claim 1 , wherein cations of the ionic liquids comprise 1-alkyl-3-methylimidazolium, n-alkylpyridinium, tetraalkylammonium, tetraalkylphosphonium, or pyrrolidinium.

4. The method of claim 1 , wherein anions of the ionic liquids comprise hexafluorophosphate, tetrafluoroborate, trifluoromethylsulfonate, bis[(trifloromethyl)sulfonyl]amide, trifluoroethanoate, or ethanoate.

5. The method of claim 1 , wherein the solid precursor comprises HfCl 4 , and the solvent comprises BmimPF 6 or BmimBF 4 .

6. The method of claim 1 , wherein the ionic liquids have viscosity smaller than 3000 centipoises (cP).

7. The method of claim 1 , wherein the solvent has a freezing point smaller than 30 Celsius (° C.) and a decomposition temperature greater than 100 Celsius (° C.).

8. The method of claim 1 , wherein the solvent has a vapor pressure smaller than 10 −8 pascal (Pa) at room temperature.

9. The method of claim 1 , wherein the solvent in the precursor ampoule is refilled and recycled through a liquid transfer assembly for a plurality of precursor ampoules.

10. A method of solid precursor delivery for a vapor deposition process, comprising:
providing a plurality of precursor ampoules, each of which comprising a first inlet for inputting a liquid precursor, a second inlet for applying a carrier gas, and an outlet for outputting a gas precursor, the liquid precursor including a ionic liquid solvent and chemical species dissolved therein;
providing a bulk canister connected to a buffer canister and coupled to the plurality of precursor ampoules through the first inlets of the plurality of precursor ampoules, the liquid precursor retained within the bulk canister and configured to transfer to the precursor ampoules;
generating the gas precursor at upper regions of the precursor ampoules by vaporization of the liquid precursor;
directing the gas precursor including the chemical species through the outlets to a plurality of vapor deposition chambers by the carrier gas; and
depositing the chemical species onto surfaces of substrates within the vapor deposition chambers.

11. The method of claim 10 , further comprising:
closing the outlet and recycling the liquid precursor within one of the plurality of precursor ampoules to a waste tank when a concentration of the chemical species in the precursor ampoule reaches a pre-determined level; and
after the recycling, directing the liquid precursor from the buffer canister to the precursor ampoule and opening the outlet to continue the deposition.

12. A method of solid precursor delivery for a vapor deposition process, comprising:
retaining a liquid precursor within a bulk canister, the liquid precursor including one or more ionic liquids as a solvent that dissolves chemical species of a solid precursor;
providing the liquid precursor from the bulk canister to a precursor ampoule including an inlet coupled with a carrier gas source and an outlet coupled with a vapor deposition chamber;
applying a carrier gas through the inlet of the precursor ampoule to create a gas precursor at an upper region of the precursor ampoule by vaporization of the liquid precursor; and
carrying the gas precursor to the vapor deposition chamber by the carrier gas through the outlet of the precursor ampoule, wherein the chemical species of the solid precursor are delivered into the vapor deposition chamber and deposited onto a surface of a substrate;
wherein the liquid precursor retained within the bulk canister is continuously provided to the precursor ampoule through a buffer canister, wherein as the liquid precursor is consumed in the precursor ampoule, the bulk canister is replaced without interrupting the vapor deposition process.

13. The method of claim 12 , further comprising applying a diffuser to be connected to the inlet of the precursor ampoule, the diffuser including a plurality of holes immersed into the liquid precursor.

14. The method of claim 12 , further comprising applying a stirring device into the precursor ampoule, the stirring device configured to facilitate dissolution of the solid precursor.

15. The method of claim 12 , further comprising:
applying a waste tank to be coupled to the precursor ampoule, the waste tank configured to recycle the solvent from the precursor ampoule during the vapor deposition process.

16. The method of claim 12 , wherein cations of the ionic liquids comprise 1-alkyl-3-methylimidazolium, n-alkylpyridinium, tetraalkylammonium, tetraalkylphosphonium, or pyrrolidinium.

17. The method of claim 12 , wherein anions of the ionic liquids comprise hexafluorophosphate, tetrafluoroborate, trifluoromethylsulfonate, bis[(trifloromethyl)sulfonyl]amide, trifluoroethanoate, or ethanoate.

18. The method of claim 12 , wherein the solid precursor comprises a metal halide compound, and the solvent comprises BmimPF 6 or BmimBF 4 .

19. The method of claim 12 , wherein the solvent has a freezing point smaller than 30 Celsius (° C.) and a decomposition temperatures greater than 100 Celsius (° C.);
wherein the solvent has a vapor pressure smaller than 10 −8 pascal (Pa).

20. The method of claim 12 , wherein solid precursor molecules are dissolved and absent from the precursor ampoule when applying the carrier gas.

Assignees

• Taiwan Semiconductor Mfg Co Ltd

Inventors

• Lee Chung-Chieh
• Yang Chi-Ming
• Wu Lin-Jung

Classifications

• C23C16/405

  of refractory metals or yttrium · CPC title

• C23C16/4482 Primary

  by bubbling of carrier gas through liquid source material · CPC title

• C23C16/4402

  Reduction of impurities in the source gas · CPC title