Etch process for oxide of alkaline earth metal

Patent metadata

Field	Value
Publication number	US-12237172-B2
Application number	US-202217746406-A
Country	US
Kind code	B2
Filing date	May 17, 2022
Priority date	May 17, 2022
Publication date	Feb 25, 2025
Grant date	Feb 25, 2025

Abstract

A method of processing a substrate that includes: loading the substrate in a plasma processing chamber, the substrate having a surface including an oxide, the oxide including an alkaline earth metal; flowing a process gas including CCl 4 into the plasma processing chamber; in the plasma processing chamber, forming a fluorine-free plasma from the process gas by applying a source power to a source electrode of the plasma processing chamber; and exposing the substrate to the fluorine-free plasma to etch the oxide of the surface.

First claim

What is claimed is:

1. A method of processing a substrate, the method comprising:
loading the substrate in a plasma processing chamber, the substrate having a surface comprising barium titanate (BaTiO 3 ) or barium stannate (BaSnO 3 );
flowing a process gas comprising CCl 4 and a bromine-containing gas into the plasma processing chamber;
in the plasma processing chamber, forming a fluorine-free plasma from the process gas by applying a source power to a source electrode of the plasma processing chamber, wherein the plasma is hydrogen-free; and
exposing the substrate to the hydrogen-free and fluorine-free plasma to etch the BaTiO 3 or BaSnO 3 .

2. The method of claim 1 , further comprising flowing a noble gas into the plasma processing chamber.

3. The method of claim 1 , wherein the process gas further comprising Cl 2 , or wherein the bromine-containing gas comprises BCl 2 Br, BClBr 2 , or BBr 3 .

4. The method of claim 1 , wherein the process gas further comprising, N 2 , NO, NO 2 , CO, CO 2 , SO 2 , or COS.

5. The method of claim 1 , wherein etching the BaTiO 3 comprises forming a volatile product comprising a carbon-oxygen bond.

6. The method of claim 1 , wherein the BaTiO 3 or BaSnO 3 is BaTiO 3 .

7. The method of claim 1 , wherein the BaTiO 3 or BaSnO 3 is BaSnO 3 .

8. A method of processing a substrate, the method comprising:
loading the substrate in a plasma processing chamber, the substrate having a surface comprising barium;
flowing a process gas into the plasma processing chamber, the process gas comprising a mixture of Cl 2 , BCl 3 , and a bromine-containing gas;
in the plasma processing chamber, forming a fluorine-free plasma from the process gas by applying a source power to a source electrode of the plasma processing chamber; and
exposing the substrate to the fluorine-free plasma to etch the barium of the surface.

9. The method of claim 8 , wherein the fluorine-free plasma is hydrogen-free.

10. The method of claim 8 , further comprising flowing a noble gas into the plasma processing chamber.

11. The method of claim 8 , wherein the surface further comprising oxygen, and wherein etching the barium comprises forming a volatile product comprising a boron-oxygen bond.

12. A method of processing a substrate, the method comprising:
loading the substrate in a plasma processing chamber, the substrate having a surface comprising barium titanate (BaTiO 3 ) or barium stannate (BaSnO 3 ); and
performing a plurality of cyclic processes, each of the plurality of cyclic processes comprising:
exposing the BaTiO 3 or BaSnO 3 to first fluorine-free species provided from a first process gas to react the BaTiO 3 or BaSnO 3 with the first fluorine-free species and to form a reaction product comprising the barium; and
exposing the reaction product to second fluorine-free species provided from a second process gas to remove the reaction product from the surface, wherein the first process gas comprises N 2 , NO, NO 2 , CO, CO 2 , SO 2 , or COS.

13. The method of claim 12 , further comprising forming a first plasma to generate the first fluorine-free species.

14. The method of claim 12 , wherein the first process gas comprises halogen other than fluorine.

15. The method of claim 12 , wherein the first process gas further comprises BCl 3 , BCl 2 Br, BClBr 2 , BBr 3 , CCl 4 , CCl 3 Br, CCl 2 Br 2 , CClBr 3 , or CBr 4 .

16. The method of claim 12 , further comprising forming a second plasma to generate the second fluorine-free species, wherein the second process gas comprises a noble gas.

17. The method of claim 12 , wherein each of the plurality of cyclic processes further comprises purging the plasma processing chamber to remove the first fluorine-free species before exposing the reaction product to the second fluorine-free species.

18. The method of claim 12 , wherein the surface comprising barium titanate (BaTiO 3 ) is free of strontium.

Assignees

• Tokyo Electron Ltd

Inventors

• Zhang Du
• Vallee Christophe
• Wang Mingmei

Classifications

• H10P50/285 Primary

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

• H10P50/283

  by chemical means · CPC title

• H10P50/267

  using plasmas · CPC title

• H10P50/28

  of insulating materials · CPC title

• H10P50/242 Primary

  of Group IV materials · CPC title