Atomic layer etching

Patent metadata

Field	Value
Publication number	US-12040195-B2
Application number	US-202318156085-A
Country	US
Kind code	B2
Filing date	Jan 18, 2023
Priority date	Dec 10, 2019
Publication date	Jul 16, 2024
Grant date	Jul 16, 2024

Abstract

Atomic layer etching (ALE) processes are disclosed. In some embodiments, the methods comprise at least one etch cycle in which a substrate comprising a metal, metal oxide, metal nitride or metal oxynitride layer is contacted with an etch reactant comprising an vapor-phase N-substituted derivative of amine compound. In some embodiments the etch reactant reacts with the substrate surface to form volatile species including metal atoms from the substrate surface. In some embodiments a metal or metal nitride surface is oxidized as part of the ALE cycle. In some embodiments a substrate surface is contacted with a halide as part of the ALE cycle. In some embodiments a substrate surface is contacted with a plasma reactant as part of the ALE cycle.

First claim

What is claimed is:

1. A method of etching a metal, metal oxide or metal nitride on a substrate surface by chemical atomic layer etching in a reaction space, the method comprising one or more etch cycles, each etch cycle comprising:
contacting the substrate surface with a vapor phase etch reactant comprising a bis(trialkylsilyl)amine to remove material from a surface of the metal, metal oxide or metal nitride and to form one or more reaction by-products including a volatile bis(trialkylsilyl) amine species; and
removing excess etch reactant and the one or more reaction by-products from the reaction space.

2. The method of claim 1 , wherein the metal, metal oxide or metal nitride comprises a metal selected from Co, Ni, Cu, Fe, Mn, Ti, Ta, Hf, Zn, La, Sc, Mo and Cr.

3. The method of claim 1 , wherein the method is part of a cyclic vapor deposition process.

4. The method of claim 1 , wherein the substrate surface is a semiconductor substrate.

5. The method of claim 1 , additionally comprising contacting the substrate surface with a vapor-phase second reactant selected from a halide, an oxidant and a plasma reactant.

6. The method of claim 5 , wherein the substrate surface is contacted with the vapor-phase second reactant after being contacted with the etch reactant.

7. The method of claim 1 , wherein each etch cycle further comprises:
contacting a metal or metal nitride on the substrate surface with an oxidant to form metal oxide on the substrate surface; and
contacting the metal oxide on the substrate surface with the vapor phase etch reactant comprising the bis(trialkylsilyl)amine.

8. The method of claim 7 , wherein the oxidant comprises O 3 , O 2 , H 2 O, H 2 O 2 , SO 3 , or excited oxygen species.

9. The method of claim 1 , wherein each etch cycle comprises contacting the substrate surface with a plasma to form a plasma-modified surface prior to contacting the substrate surface with the etch reactant.

10. The method of claim 9 , wherein the plasma comprises a plasma generated in a gas comprising hydrogen, nitrogen, a nitrogen-hydrogen mixture, argon, or helium.

11. The method of claim 1 , wherein the bis(trialkylsilyl)amine is a N-substituted bis(trialkylsilyl)amine.

12. The method of claim 11 , wherein the N-substituted bis(trialkylsilyl)amine comprises a functional group selected from —F, —Cl, —Br and —I.

13. The method of claim 11 , wherein the N-substituted bis(trialkylsilyl)amine comprises a functional group selected from —CN and H.

14. The method of claim 1 , wherein each etch cycle further comprises:
contacting the metal, metal oxide or metal nitride on the substrate surface with a vapor-phase halide reactant to form a halidized surface; and
contacting the halidized surface with the vapor phase etch reactant comprising the bis(trialkylsilyl)amine.

15. The method of claim 14 , wherein prior to contacting the substrate surface with the vapor-phase halide reactant the substrate surface comprises a metal or metal nitride and the metal or metal nitride is contacted with an oxidant to form a metal oxide.

16. The method of claim 14 , wherein the halide reactant comprises a metal halide, a non-metal halide, an organic halide, or an interhalogen.

Assignees

• Asm Ip Holding Bv

Inventors

• Dezelah Charles
• Sharma Varun

Classifications

• H10P50/244 Primary

  comprising alternated and repeated etching and passivation steps · CPC title

• H10P50/285 Primary

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

• C23F1/32

  Alkaline compositions (C23F1/42 takes precedence) · CPC title

• H01J37/32009

  Arrangements for generation of plasma specially adapted for examination or treatment of objects, e.g. plasma sources (plasma generation in general H05H1/24) · CPC title

• C23F1/12

  Gaseous compositions · CPC title