Method for etching for semiconductor fabrication

Patent metadata

Field	Value
Publication number	US-12400863-B2
Application number	US-202217704372-A
Country	US
Kind code	B2
Filing date	Mar 25, 2022
Priority date	Mar 25, 2022
Publication date	Aug 26, 2025
Grant date	Aug 26, 2025

Abstract

A method of processing a substrate includes patterning a mask over a dielectric layer and etching openings in the dielectric layer. The dielectric layer is disposed over the substrate. The etching includes flowing an etchant, a polar or H-containing gas, and a phosphorus-halide gas. The method may further include forming contacts by filling the openings with a conductive material.

First claim

What is claimed is:

1. A method of processing a substrate, the method comprising:
patterning a mask over a dielectric layer, the dielectric layer disposed over the substrate;
etching openings in the dielectric layer, the etching comprising:
flowing an etchant, a polar or H-containing gas, and a phosphorus-halide gas; and
forming a catalyst comprising a phosphorus-containing acid; and

forming contacts by filling the openings with a conductive material.

2. The method of claim 1 , wherein the etchant is HF or HCl.

3. The method of claim 1 , wherein the polar or H-containing gas comprises water vapor (H 2 O), hydrogen peroxide (H 2 O 2 ), hydrogen (H 2 ), a mixture of hydrogen (H 2 ) and oxygen (O 2 ), or hydrogen bromide (HBr).

4. The method of claim 1 , wherein the phosphorus-halide gas comprises phosphorus trifluoride (PF 3 ), phosphorus trichloride (PCl 3 ), phosphoryl fluoride (POF 3 ), or phosphoryl chloride (POCl 3 ).

5. The method of claim 1 , wherein the dielectric layer comprises silicon oxide or silicon nitride.

6. The method of claim 5 , wherein the dielectric layer comprises an O/N/O/N stack.

7. The method of claim 1 , wherein the etching anisotropically etches the openings in an anisotropic etch process.

8. The method of claim 7 , wherein the anisotropic etch process is performed as a plasma process in a plasma processing system.

9. The method of claim 1 , wherein the contacts have respective aspect ratios greater than 50:1.

10. A method of processing a substrate, the method comprising:
performing a cyclic etching process, wherein each cycle of the cyclic etching process comprises:
flowing an etchant over a dielectric layer on the substrate, the substrate being in a process chamber;
forming a catalyst in the process chamber by simultaneously flowing a polar or H-containing gas and a phosphorus-halide gas over the dielectric layer in the process chamber; and
purging the catalyst from the process chamber.

11. The method of claim 10 , wherein the etchant is HF.

12. The method of claim 10 , wherein the phosphorus-halide gas is phosphorus trifluoride (PF 3 ).

13. The method of claim 10 , wherein the catalyst comprises PF 2 OH.

14. The method of claim 10 , wherein the cyclic etching process is a plasma process.

15. The method of claim 10 , wherein the cyclic etching process is anisotropic.

16. A method of processing a substrate in a process chamber, the method comprising:
simultaneously flowing an etchant and a polar or H-containing gas over a dielectric layer comprising an exposed surface of the substrate; and
performing a cyclic tuning process, wherein each cycle of the cyclic tuning process comprises:
adjusting a temperature of the process chamber; and
flowing a phosphorus-halide gas over the dielectric layer.

17. The method of claim 16 , wherein the polar or H-containing gas comprises H 2 O.

18. The method of claim 16 , wherein the phosphorus-halide gas comprises phosphorus and fluorine.

19. The method of claim 16 , wherein the dielectric layer comprises silicon oxide.

20. The method of claim 16 , further comprising forming an opening in the dielectric layer, the opening having an aspect ratio greater than 50:1.

Assignees

• Tokyo Electron Ltd

Inventors

• Tsai Yu-Hao
• Zhang Du
• Wang Mingmei
• ORUI Takatoshi
• Takahashi Motoi
• Yokoi Masahiko
• Tanaka Koki
• Kihara Yoshihide

Classifications

• H10P50/242 Primary

  of Group IV materials · CPC title

• H10P50/283 Primary

  by chemical means · CPC title

• H01J2237/334

  Etching · CPC title

• H01J37/32449

  Gas control, e.g. control of the gas flow · CPC title

• H01J37/32174

  Circuits specially adapted for controlling the RF discharge · CPC title