Atomic layer etching using a boron-containing gas and hydrogen fluoride gas

Patent metadata

Field	Value
Publication number	US-10790156-B2
Application number	US-201916405462-A
Country	US
Kind code	B2
Filing date	May 7, 2019
Priority date	Aug 10, 2016
Publication date	Sep 29, 2020
Grant date	Sep 29, 2020

Abstract

Embodiments of the invention provide a method for atomic layer etching (ALE) of a substrate. According to one embodiment, the method includes providing a substrate, and exposing the substrate to hydrogen fluoride (HF) gas and a boron-containing gas to etch the substrate. According to another embodiment, the method includes providing a substrate containing a metal oxide film, exposing the substrate to HF gas to form a fluorinated surface layer on the metal oxide film, and exposing the substrate to a boron-containing gas to remove the fluorinated surface layer from the metal oxide film. The exposures may be repeated at least once to further etch the metal oxide film.

First claim

What is claimed is:

1. A method of atomic layer etching (ALE), the method comprising:
providing a substrate; and
in the absence of a plasma, exposing the substrate to hydrogen fluoride (HF) gas and a boron-containing gas to etch the substrate, wherein the exposing includes alternating exposures to the hydrogen fluoride gas and the boron-containing gas that are repeated at least once to further etch the substrate.

2. The method of claim 1 , wherein the boron-containing gas contains a boron hydride, a boron halide, a boron amide, an organo boride, or a combination thereof.

3. The method of claim 1 , wherein the boron-containing gas is selected from the group consisting of BH 3 , BCl 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

4. The method of claim 1 , wherein the boron-containing gas is selected from the group consisting of BH 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

5. A method of atomic layer etching (ALE), the method comprising:
providing a substrate containing a metal oxide film;
exposing the substrate to hydrogen fluoride (HF) gas to form a fluorinated surface layer on the metal oxide film; and
exposing the substrate to a boron-containing gas to remove the fluorinated surface layer from the metal oxide film, wherein the exposing steps are performed in the absence of a plasma.

6. The method of claim 5 , wherein the exposures are repeated at least once to further etch the metal oxide film.

7. The method of claim 5 , wherein the boron-containing gas contains a boron hydride, a boron halide, a boron amide, an organo boride, or a combination thereof.

8. The method of claim 5 , wherein the boron-containing gas is selected from the group consisting of BH 3 , BCl 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

9. The method of claim 5 , wherein the boron-containing gas is selected from the group consisting of BH 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

10. The method of claim 5 , wherein the metal oxide film is selected from the group consisting of Al 2 O 3 , HfO 2 , TiO 2 , ZrO 2 , Y 2 O 3 , La 2 O 3 , UO 2 , Lu 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZnO, MgO, CaO, BeO, V 2 O 5 , FeO, FeO 2 , CrO, Cr 2 O 3 , CrO 2 , MnO, Mn 2 O 3 , RuO, CoO, WO 3 , and combinations thereof.

11. The method of claim 5 , further comprising gas purging with an inert gas between the exposing steps.

12. A method of atomic layer etching (ALE), the method comprising:
providing a substrate; and
in the absence of a plasma, exposing the substrate to hydrogen fluoride (HF) gas and a boron-containing gas to etch the substrate, wherein the boron-containing gas contains a boron hydride, a boron halide, a boron amide, an organo boride, or a combination thereof, and wherein the exposing includes alternating exposures to the hydrogen fluoride gas and the boron-containing gas that are repeated at least once to further etch the substrate.

13. The method of claim 12 , wherein the boron-containing gas is selected from the group consisting of BH 3 , BCl 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

14. The method of claim 12 , wherein the boron-containing gas is selected from the group consisting of BH 3 , B(CH 3 ) 3 , and B(N(CH 3 ) 2 ) 3 .

15. The method of claim 12 , wherein the substrate contains a metal oxide film selected from the group consisting of Al 2 O 3 , HfO 2 , TiO 2 , ZrO 2 , Y 2 O 3 , La 2 O 3 , UO 2 , Lu 2 O 3 , Ta 2 O 5 , Nb 2 O 5 , ZnO, MgO, CaO, BeO, V 2 O 5 , FeO, FeO 2 , CrO, Cr 2 O 3 , CrO 2 , MnO, Mn 2 O 3 , RuO, CoO, WO 3 , and combinations thereof.

16. The method of claim 12 , further comprising gas purging with an inert gas between the alternating exposures.

Assignees

• Tokyo Electron Ltd

Inventors

• Clark Robert D
• Tapily Kandabara N

Classifications

• H10P50/287

  by chemical means · CPC title

• H10P50/285

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

• H10P50/283 Primary

  by chemical means · CPC title

• C01B7/191 Primary

  Hydrogen fluoride · CPC title

• H10P14/6339

  deposition by cyclic CVD, e.g. ALD, ALE or pulsed CVD · CPC title