Thermal atomic layer etching processes

Patent metadata

Field	Value
Publication number	US-11739428-B2
Application number	US-202117646389-A
Country	US
Kind code	B2
Filing date	Dec 29, 2021
Priority date	Dec 9, 2016
Publication date	Aug 29, 2023
Grant date	Aug 29, 2023

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 by chemical atomic layer etching, the method comprising one or more etching cycles comprising:
exposing the substrate to a first vapor-phase non-metal oxyhalide reactant and a second vapor-phase halide reactant;
subsequently exposing the substrate to a third, different vapor-phase reactant, such that volatile species comprising one or more atoms from the film are formed; and,
removing the volatile species from the vicinity of the substrate, wherein the substrate is not contacted with a plasma reactant during the etching cycle.

2. The method of claim 1 , wherein the substrate is not contacted with HF during the etching cycle.

3. The method of claim 1 , wherein exposing the substrate to first vapor-phase non-metal oxyhalide reactant and a second vapor-phase halide reactant comprises flowing the first vapor-phase non-metal oxyhalide reactant and the second vapor-phase halide reactant continuously into a reaction space containing the substrate during the etching cycle.

4. The method of claim 1 , wherein exposing the substrate to a first vapor-phase non-metal oxyhalide reactant and a second vapor-phase halide reactant comprises flowing the first vapor-phase non-metal oxyhalide reactant and the second vapor-phase halide reactant sequentially into a reaction chamber containing the substrate.

5. The method of claim 1 , wherein removing volatile species from the vicinity of the substrate comprises moving the substrate.

6. The method of claim 5 , wherein the substrate is moved from a first reaction chamber to a second, different reaction chamber.

7. The method of claim 1 , wherein the second vapor-phase halide reactant comprises a metal or semi-metal.

8. The method of claim 7 , wherein the second vapor-phase halide reactant comprises Te, Sb, As, Nb, Ta, Mo, Sn, V, Re, Te, W or a group 6 transition metal.

9. The method of claim 1 , wherein the second vapor phase halide reactant comprises sulfur atoms.

10. The method of claim 1 , wherein the second vapor phase halide reactant comprises an oxyhalide.

11. The method of claim 1 , wherein the first vapor phase non-metal oxyhalide reactant comprises carbon.

12. The method of claim 1 , wherein the third vapor-phase reactant comprises H 2 O 2 , HCOOH, H 2 O, O 2 or O 3 .

13. The method of claim 1 , wherein the third vapor-phase reactant comprises CS 2 , pyridine, tetrahydrofuran, DMSO, or tetrahydrothiophene.

14. The method of claim 1 , wherein the third vapor-phase reactant comprises BCl 3 , BF 3 or AlCl 3 .

15. The method of claim 1 , wherein the third vapor-phase reactant comprises a nitrile, an isonitrile, a thiocyanate, an isothiocyanate, a diamine, a diketone, a dithione or an atrane compound.

16. The method of claim 1 , wherein the third vapor-phase reactant comprises trimethylaluminum (TMA), Hacac, Sn(acac) 2 , or Hhfac.

17. The method of claim 1 , wherein the third vapor-phase reactant comprises a carboxylic acid or an alcohol.

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

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

20. The method of claim 1 , wherein the first vapor-phase non-metal oxyhalide reactant comprises sulfur and/or nitrogen.

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

22. The method of claim 1 , wherein the substrate comprises two or more different materials and one material is selectively etched relative to the other materials in each etching cycle.

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

24. The method of claim 23 , wherein the film comprises TiN, TiO 2 , TaN, SiN, SiO x , AlO x , AlO 2 , Al 2 O 3 , ZrO x , ZrO 2 , WO 3 , AlN, HfO x or HfO 2 .

25. The method of claim 23 , wherein the film comprises Ti, Mo, Cu, Co, W, Si, Ta, Al, Zr, Hf, Ge, Pt, Ni, Zn, Nb Ir, Ru, Rh, or Sb.

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

27. 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
• Tuominen Marko
• 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