Thermal atomic layer etching processes

Patent metadata

Field	Value
Publication number	US-11230769-B2
Application number	US-202016881718-A
Country	US
Kind code	B2
Filing date	May 22, 2020
Priority date	Dec 9, 2016
Publication date	Jan 25, 2022
Grant date	Jan 25, 2022

Abstract

Thermal atomic layer etching processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which the substrate is alternately and sequentially exposed to a first vapor phase halide reactant and a second vapor halide reactant. In some embodiments, the first reactant may comprise an organic halide compound. During the thermal ALE cycle, the substrate is not contacted with a plasma reactant.

First claim

What is claimed is:

1. A method of etching a film on a substrate in a reaction chamber by chemical atomic layer etching, the method comprising a plurality of etching cycles, each etching cycle comprising:
exposing the substrate to a first vapor-phase non-metal oxyhalide reactant; and
removing excess first vapor-phase non-metal oxyhalide halide reactant and byproducts from the reaction chamber,
wherein the substrate is not contacted with a plasma reactant during the etching cycle.

2. The method of claim 1 , further comprising exposing the substrate to a vapor-phase metal or semi-metal halide reactant.

3. The method of claim 2 , wherein the vapor-phase metal or semi-metal halide reactant comprises Te, Sb, As, Nb, Ta, Mo, Sn, V, Re, Te, W or a group 6 transition metal.

4. The method of claim 2 , wherein the vapor phase metal or semi-metal halide reactant comprises sulfur atoms.

5. The method of claim 2 , wherein the vapor phase metal or semi-metal halide reactant comprises oxygen atoms.

6. The method of claim 1 , wherein the first vapor phase oxyhalide reactant comprises carbon, oxygen and halide atoms.

7. The method of claim 1 , further comprising exposing the substrate to a second vapor-phase oxyhalide reactant.

8. The method of claim 7 , wherein the etch cycle additionally comprises exposing the substrate to a third vapor-phase reactant that is different from the first and second vapor-phase oxyhalide reactants.

9. The method of claim 8 , where the third vapor-phase reactant comprises oxygen.

10. The method of claim 9 , wherein the third vapor-phase reactant comprises H 2 O 2 , HCOOH, H 2 O, O 2 or O 3 .

11. The method of claim 8 , where the third vapor-phase reactant comprises a ligand exchanger.

12. The method of claim 11 , wherein the third vapor-phase reactant comprises trimethylaluminum (TMA), Hacac, Sn(acac) 2 , or Hhfac.

13. The method of claim 8 , where the third vapor phase reactant comprises an adduct forming compound.

14. The method of claim 13 , wherein the adduct forming compound is CS 2 , CH 3 CN, NH 3 , SO 3 , tris(2-aminoethyl)amine, triethanolamine, pyridine, tetrahydrofuran (THF), dimethylsulfoxide (DMSO), tetrahydrothiophene, 1, 4-dioxane, an isocyanate, a poly-ol, ethanolamine, a sulfone, trichloromethane, an alkyl or substituted isothiocyanate, trichloronitromethane, an alkyl, aryl or substituted nitrile, an isonitrile, a diamine, a dithione, a sulfone, TIPA, TIPEA, TMEA or a heterocylic reactive compound.

15. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises a semi-metal.

16. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant does not comprise carbon.

17. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant does not comprise a hydrocarbon group.

18. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant does not comprise hydrogen.

19. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant does not comprise hydrogen or carbon.

20. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises sulfur, halide and oxygen atoms.

21. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises halide and nitrogen atoms.

22. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises sulfur, halide and nitrogen atoms.

23. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises sulfur, halide, oxygen and nitrogen atoms.

24. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises of sulfur, halide, carbon and nitrogen atoms.

25. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises of sulfur, halide, carbon, oxygen and nitrogen atoms.

26. The method of claim 1 , wherein the substrate comprises two or more different materials that are exposed to the first vapor-phase non-metal oxyhalide reactant and one material is selectively etched relative to the other materials.

27. The method of claim 1 , wherein the film comprises a metal oxide, metal carbide, metal nitride or is an elemental film.

28. The method of claim 27 , wherein the film comprises Ti, Mo, Cu, Co, W, Si, Ta, Al, Zr, Hf, Ge, Pt, Ni, Zn, Nb 1 r, Ru, Rh, or Sb.

29. The method of claim 1 , wherein the temperature of the substrate during the etching cycle is 150° C. to 600° C.

30. The method of claim 1 , wherein the substrate is a semiconductor wafer.

31. The method of claim 1 , wherein the method has an average etch rate of 0.01 to 5 Å/cycle.

Assignees

• Asm Ip Holding Bv

Inventors

• Blomberg Tom E
• Sharma Varun
• Haukka Suvi P
• Tuominen Marko J
• Zhu chiyu

Classifications

• H10P50/287

  by chemical means · CPC title

• H10P50/285

  of materials not containing Si, e.g. PZT or Al2O3 · CPC title

• H10P50/283

  by chemical means · CPC title

• H10P50/266

  by vapour etching only · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title