US-12628595-B2 - Plasma processing method and plasma processing apparatus

Abstract

A plasma processing method according to the present disclosure is performed with a plasma processing apparatus, and includes: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; and (b) etching the etching target film. (b) includes supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film to form the opening pattern in the first silicon-containing film, and a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more.

Inventors

• Takahiro Yonezawa
• Yusuke Takino
• Kenta ONO
• Tetsuya Nishizuka

Assignees

• TOKYO ELECTRON LIMITED

Dates

Publication Date

20260512

Application Date

20230519

Priority Date

20220520

Claims (20)

1. 1 . A plasma processing method performed with a plasma processing apparatus having a chamber, comprising: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern, wherein the first metal-containing film comprises a Sn-containing film, and wherein the Sn-containing film is a photoresist film for EUV; and (b) etching the etching target film, wherein (b) including supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film to form the opening pattern in the first silicon-containing film, and wherein a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas being 0.3 or more, and wherein the bias signal is a RF signal, and the power of the bias signal has an effective value that is 200 W or less.
2. 2 . The plasma processing method according to claim 1 , wherein the first silicon-containing film includes at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a film stack thereof.
3. 3 . The plasma processing method according to claim 1 , wherein the etching target film includes an intermediate film on the first silicon-containing film, (b) includes etching the intermediate film using the first metal-containing film as a mask, and forming the opening pattern includes etching the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask.
4. 4 . The plasma processing method according to claim 3 , wherein plasma is continuously formed in the chamber from etching the intermediate film to forming the opening.
5. 5 . The plasma processing method according to claim 3 , wherein the intermediate film includes at least one selected from the group consisting of a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film.
6. 6 . The plasma processing method according to claim 5 , wherein the intermediate film includes the carbon-containing film and a second silicon-containing film on the carbon-containing film, and the second silicon-containing film includes at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a film stack thereof.
7. 7 . The plasma processing method according to claim 1 , wherein the processing gas includes hydrogen-containing gas, carbon-containing gas, and fluorine-containing gas.
8. 8 . The plasma processing method according to claim 7 , wherein the carbon-containing gas includes a gas that further includes at least one of hydrogen and fluorine.
9. 9 . The plasma processing method according to claim 7 , wherein the fluorine-containing gas includes a gas that does not contain carbon.
10. 10 . The plasma processing method according to claim 1 , wherein a ratio of the number of hydrogen atoms to the number of carbon atoms in the processing gas is 0.3 or more.
11. 11 . The plasma processing method according to claim 1 , wherein in forming the opening, the first silicon-containing film is etched using the first metal-containing film as a mask.
12. 12 . The plasma processing method according to claim 1 , wherein forming the opening pattern includes controlling the pressure in the chamber to 100 mTorr or less.
13. 13 . The plasma processing method according to claim 1 , wherein the plasma processing apparatus includes: a first gas injector disposed on an upper face of the chamber so as to face the substrate support; and a second gas injector disposed on a side face of the chamber, wherein the processing gas includes one or more gases containing carbon and one or more gases without carbon, at least one of the one or more gases containing carbon is supplied from the first gas injector, and at least one of the one or more gases without carbon is supplied from the second gas injector.
14. 14 . The plasma processing method according to claim 1 , wherein the plasma processing apparatus includes: a first gas injector disposed in the chamber on an upper face of the chamber; and a second gas injector disposed in the chamber on a side face of the chamber, wherein the processing gas includes at least one carbon-containing gas, the at least one carbon-containing gas is supplied into the chamber from the first gas injector and the second gas injector, and a ratio of a flow rate of the at least one carbon-containing gas supplied into the chamber from the first gas injector to a flow rate of the at least one carbon-containing gas supplied into the chamber from the second gas injector is less than 1.
15. 15 . The plasma processing method according to claim 1 , wherein the plasma processing apparatus includes a plasma generator above the substrate support, wherein forming the opening pattern includes: supplying a source RF signal to the plasma generator to form a plasma from the processing gas; and supplying a bias signal to the substrate support, and wherein the power of the source RF signal has an effective value that is greater than an effective value of the power of the bias signal.
16. 16 . The plasma processing method according to claim 15 , wherein the plasma generator includes an electrode facing the substrate support.
17. 17 . The plasma processing method according to claim 15 , wherein the plasma generator includes an antenna disposed above the substrate support.
18. 18 . The plasma processing method according to claim 15 , wherein the power of the source RF signal has an effective value that is 500 W or more.
19. 19 . A plasma processing method performed with a plasma processing apparatus having a chamber, comprising: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film and an intermediate film on the first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; and (b) etching the etching target film, wherein (b) includes etching the intermediate film using the first metal-containing film as a mask, and supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask to form the opening pattern in the first silicon-containing film, wherein a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more, and wherein the pressure in the chamber in forming the opening pattern is lower than the pressure in the chamber in etching the intermediate film.
20. 20 . A plasma processing method performed with a plasma processing apparatus having a chamber, comprising: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film and an intermediate film on the first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; and (b) etching the etching target film, wherein (b) includes etching the intermediate film using the first metal-containing film as a mask, and supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask to form the opening pattern in the first silicon-containing film, wherein a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more, wherein deposits containing a metal included in the first metal-containing film are generated in etching the intermediate film, and forming the opening pattern includes removing the deposits adhering to the substrate.

Description

CROSS-REFERENCE TO RELATED APPLICATION The present application claims priority under 35 U.S.C. § 119 to Japanese Patent Application No. 2022-082706 filed on May 20, 2022 and Japanese Patent Application No. 2023-074798 filed on Apr. 28, 2023, the entire contents of which are incorporated herein by reference. BACKGROUND Field Exemplary embodiments of the present disclosure relate to plasma processing methods and plasma processing systems. Description of Related Art U.S. Pat. No. 9,899,219 discloses a technique of trimming an inorganic resist using a processing gas containing CH3F or BCl3 to uniformize the dimensions of a pattern formed in the resist. SUMMARY One exemplary embodiment of the present disclosure provides a plasma processing method performed with a plasma processing apparatus having a chamber. The plasma processing method includes: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; and (b) etching the etching target film. (b) includes supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film to form the opening pattern in the first silicon-containing film, and a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 describes a configuration example of a plasma processing system. FIG. 2 describes a configuration example of a plasma processing apparatus. FIG. 3 is a flowchart illustrating an example of the present processing method. FIG. 4A illustrates an example of the cross-sectional structure of a substrate W. FIG. 4B illustrates an example of the cross-sectional structure of a substrate W. FIG. 4C illustrates an example of the cross-sectional structure of a substrate W. FIG. 4D illustrates an example of the cross-sectional structure of a substrate W. FIG. 4E illustrates an example of the cross-sectional structure of a substrate W. FIG. 5 schematically illustrates an example of the cross-section of the substrate W after the substrate W was etched in step ST23. FIG. 6 is a graph indicating the defect density of the silicon-containing film SF-1. FIG. 7 is a graph indicating the LWR and LER of the silicon-containing film SF-1. DETAILED DESCRIPTION The following describes embodiments of the present disclosure. One exemplary embodiment provides a plasma processing method performed with a plasma processing apparatus having a chamber. The plasma processing method includes: (a) preparing a substrate on a substrate support in the chamber, the substrate having an etching target film including a first silicon-containing film, and a first metal-containing film on the etching target film, the first metal-containing film including an opening pattern; and (b) etching the etching target film. (b) includes supplying a processing gas including one or more gases containing carbon, hydrogen, and fluorine into the chamber to form a plasma from the processing gas within the chamber and etch the first silicon-containing film to form the opening pattern in the first silicon-containing film, and a ratio of the number of hydrogen atoms to the number of fluorine atoms in the processing gas is 0.3 or more. In one exemplary embodiment, the first metal-containing film includes a Sn-containing film. In one exemplary embodiment, the first silicon-containing film includes at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a film stack thereof. In one exemplary embodiment, the etching target film includes an intermediate film on the first silicon-containing film, (b) includes etching the intermediate film using the first metal-containing film as a mask, and forming the opening pattern includes etching the first silicon-containing film using at least one of the first metal-containing film and the intermediate film as a mask. In one exemplary embodiment, the intermediate film includes at least one selected from the group consisting of a carbon-containing film, a second silicon-containing film different from the first silicon-containing film, and a second metal-containing film different from the first metal-containing film. In one exemplary embodiment, the intermediate film includes the carbon-containing film and a second silicon-containing film on the carbon-containing film, and the second silicon-containing film includes at least one selected from the group consisting of a film containing silicon and oxygen, a film containing silicon and nitrogen, and a film stack thereof. In one exemplary embodiment, the processing gas includes hydrogen-containing gas, carbon-containing gas, and fluo