Thermal atomic layer etching processes

Patent metadata

Field	Value
Publication number	US-2018166255-A1
Application number	US-201715835212-A
Country	US
Kind code	A1
Filing date	Dec 7, 2017
Priority date	Dec 9, 2016
Publication date	Jun 14, 2018
Grant date	—

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 the surface of a substrate in a reaction chamber by chemical atomic layer etching, the method comprising one or more etching cycles, each cycle comprising:
exposing the substrate to a first vapor-phase halide reactant comprising a first halide ligand to form adsorbed species on the substrate surface, wherein the first vapor-phase halide reactant does not comprise hydrogen; and subsequently exposing the substrate to a second vapor-phase halide reactant comprising a second halide ligand that converts the adsorbed species into volatile species such that at least some material is removed from the film, wherein the second vapor-phase halide reactant does not comprise hydrogen; and wherein the substrate is not contacted with a plasma reactant during the etching cycle.

2 . The method of claim 1 , wherein the film comprises W, TiN, TiO 2 , TaN, SiN, AlO 2 , Al 2 O 3 , ZrO 2 , WO 3 , SiOCN, SiOC, SiCN, AlN or HfO 2 .

3 . The method of claim 1 , wherein the first vapor-phase halide reactant comprise a metal halide.

4 . The method of claim 3 , wherein the metal halide comprises a metal selected from Nb, Ta, Mo, Sn, V, Re, Te, W, and group 5 and 6 transition metals.

5 . The method of claim 1 , wherein the first vapor-phase halide reactant does not comprise a metal.

6 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises an organic halide compound.

7 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises an alkyl halide, an acyl halide, a sulfonyl halide, a sulfenyl halide, a selenyl halide, or a boron halide comprising an organic ligand.

8 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises fluorosulfonic acid, trifluoromethanesulfonic acid, trifluoromethyl trifluoromethanesulfonate, sulfur tetrafluoride sulfur chloride pentafluoride or sulfur hexafluoride, or 1-chloro 2-(pentafluorosulfuranyloxy)ethane.

9 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises chlorosulfonyl isocyanate or N,N-dimethylsulfamoyl chloride.

10 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises boron, hydrogen, and a halide.

11 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises phosphorus, oxygen, and a halide.

12 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises antimony and a halide.

13 . The method of claim 1 , wherein the first vapor-phase halide reactant comprises one or more —CF 3 groups.

14 . The method of claim 1 , further comprising repeating the etching cycle two or more times sequentially.

15 . The method of claim 1 , wherein the first and second halide ligands are Cl.

16 . The method of claim 1 , wherein the second vapor-phase halide reactant does not comprise metal.

17 . The method of claim 1 , wherein the second vapor-phase halide reactant is a carbon based halide.

18 . The method of claim 17 , wherein the second vapor phase halide reactant comprises CCl 4 or CBr 4 .

19 . The method of claim 1 , wherein the temperature of the substrate during the etching cycle is 300° C. to 500° C.

20 . A method of etching a film on the surface of a substrate in a reaction chamber by chemical atomic layer etching, the method comprising one or more etching cycles, each cycle comprising:
exposing the substrate to a first vapor-phase reactant such that the first vapor-phase reactant reacts with a molecule on the substrate surface to form reactant species on the substrate surface; and subsequently exposing the substrate to a second vapor-phase reactant such that the reactant species are converted into volatile reaction products and a portion of the film is removed from the substrate surface, wherein the substrate is not contacted with a plasma reactant during the etching cycle.

21 . A method of claim 20 , wherein the first vapor-phase reactant comprises CSe 2 .

22 . A method of claim 20 , wherein the first vapor-phase reactant comprises compounds with S═R═S structure in which R can be carbon or any hydrocarbon, such as C2-C8.

23 . The method of claim 22 , wherein the first vapor-phase reactant comprises CS 2 .

24 . The method of claim 20 , wherein the second vapor-phase reactant comprises triethylaluminum (TEA) or trimethylaluminum (TMA).

25 . A method of etching a film on a substrate in a reaction chamber comprising two or more etching cycles, each cycle comprising:
exposing the substrate to a first vapor-phase halide reactant that does not comprise hydrogen; and subsequently exposing the substrate to a second, different vapor-phase halide reactant that does not comprise hydrogen; and exposing the substrate to a third vapor-phase reactant that is different from the first and second vapor-phase reactants, wherein the substrate is not contacted with a plasma reactant during the etching cycle.

26 . The method of claim 25 , wherein the additional vapor phase reactant comprises one or more of SO 3 , H 2 S, NH 3 , H2O, HCOOH, H2O2, and hydrazine.

27 . A method for etching a thin film on a substrate surface comprising:
exposing the substrate surface to a first vapor-phase halide reactant comprising a first halide ligand to form first reactant species on the substrate surface, wherein the first vapor-phase halide reactant does not comprise hydrogen; and subsequently exposing the substrate to a second vapor-phase halide reactant comprising a second halide ligand such that the second vapor-phase halide reactant converts the first reactant species to vapor phase reaction products, wherein the second vapor-phase halide reactant does not comprise hydrogen, and, wherein the formation of the first reactant species or the conversion of the second vapor-phase halide reactant to vapor phase reaction products are not self-limiting.

28 . The method of claim 27 , wherein the substrate is not contacted with a plasma reactant during the etching cycle.

29 . The method of claim 27 , wherein the formation of the first reactant species and the conversion of the second vapor-phase halide reactant to vapor phase reaction products are not self-limiting.

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