JP-7855401-B2 - Plasma treatment method and plasma treatment system

JP7855401B2JP 7855401 B2JP7855401 B2JP 7855401B2JP-7855401-B2

Inventors

吉越大祐
清水祐介
田原慈

Assignees

東京エレクトロン株式会社

Dates

Publication Date: 20260508
Application Date: 20220519

Claims (18)

A plasma processing method performed in a plasma processing apparatus having a chamber, (a) A step of preparing a substrate having a film to be etched and a metal-containing film provided on the film to be etched on a substrate support portion in a chamber, wherein the metal-containing film has an exposed first region and an unexposed second region, (b) A step of modifying the metal-containing film using a first plasma generated from a first processing gas containing either a fluorine-containing gas or an oxygen-containing gas, (c) A step of selectively removing the first region of the modified metal-containing film relative to the second region using a second plasma generated from the second processing gas, A plasma treatment method, including the following.
The plasma treatment method according to claim 1, wherein the modification in step (b) results in the etching resistance of the second region to the second plasma being greater than the etching resistance of the first region to the second plasma.
The plasma treatment method according to claim 2, wherein step (c) removes the first region so that the film to be etched is exposed.
The plasma treatment method according to any one of claims 1 to 3, wherein the metal-containing film contains tin or titanium.
The plasma treatment method according to claim 4, wherein the metal-containing film contains an organic substance.
The plasma treatment method according to claim 1, wherein the first treatment gas comprises at least one selected from the group consisting of fluorocarbon gas, hydrofluorocarbon gas, NF3 gas, and SF6 gas.
The plasma treatment method according to claim 6, wherein the second treatment gas includes a chlorine-containing gas.
The plasma treatment method according to claim 7, wherein the chlorine-containing gas is BCl3 gas or Cl2 gas.
The plasma treatment method according to claim 1, wherein the first treatment gas comprises at least one selected from the group consisting of O2 gas, CO gas, and CO2 gas.
The plasma treatment method according to claim 9, wherein the first treatment gas further comprises a chlorine-containing gas.
The plasma treatment method according to claim 10, wherein the chlorine-containing gas is at least one selected from the group consisting of Cl₂ gas, BCl₃ gas, and SiCl₄ gas.
The plasma treatment method according to claim 9, wherein step (c) involves alternately repeating the process of generating the second plasma using a gas containing hydrogen and nitrogen as the second treatment gas, and generating the second plasma using a gas containing chlorine as the second treatment gas.
The plasma treatment method according to claim 1, wherein the etching target film is a Si-containing film or a carbon-containing film.
The plasma treatment method according to claim 1, further comprising the step of (d) etching the film to be etched using the metal-containing film as a mask, after step (c).
The plasma treatment method according to claim 14, wherein steps (a) to (d) are performed in the same chamber.
The plasma processing method according to claim 1, wherein the metal-containing film includes a metal-containing photoresist film, the first region is an exposed region of the metal-containing photoresist film, and the second region is an unexposed region of the metal-containing photoresist.
The plasma treatment method according to claim 16, wherein the first region is exposed to EUV light.
A plasma processing system having a chamber, a substrate support section provided within the chamber, and a control section, The control unit, (a) A control for preparing a substrate on a substrate support portion, the substrate having a film to be etched and a metal-containing film provided on the film to be etched, wherein the metal-containing film has an exposed first region and an unexposed second region, (b) Control for modifying the metal-containing film using a first plasma generated from a first processing gas containing either a fluorine-containing gas or an oxygen-containing gas, (c) Control is performed which includes a control that uses a second plasma generated from a second processing gas to selectively remove the first region of the modified metal-containing film relative to the second region. Plasma processing system.

Description

Exemplary embodiments of the present invention relate to a plasma treatment method and a plasma treatment system. Patent Document 1 discloses a technique for trimming non-organic films. U.S. Patent Application No. 2017/0243744 This is a schematic diagram illustrating an exemplary plasma processing system.This is a flowchart of the processing method.This figure schematically shows an example of the cross-sectional structure of the substrate W provided in process ST1.This figure schematically shows an example of the cross-sectional structure of the substrate W after processing in step ST2.This figure schematically shows an example of the cross-sectional structure of the substrate W after processing in step ST3.This figure schematically shows an example of the cross-sectional structure of the substrate W after processing in step ST4. The embodiments of this disclosure are described below. In one exemplary embodiment, a plasma processing method is provided, performed in a plasma processing apparatus having a chamber, comprising: (a) preparing a substrate having a film to be etched and a metal-containing film provided on the film to be etched on a substrate support within the chamber, wherein the metal-containing film has an exposed first region and an unexposed second region; (b) modifying the metal-containing film using a first plasma generated from a first processing gas containing either a fluorine-containing gas or an oxygen-containing gas; and (c) selectively removing the first region of the modified metal-containing film relative to the second region using a second plasma generated from a second processing gas. In one exemplary embodiment, the modification in step (b) results in greater etching resistance of the second region to the second plasma than that of the first region to the second plasma. In one exemplary embodiment, step (c) removes the first region so that the film to be etched is exposed. In one exemplary embodiment, the metal-containing film comprises tin or titanium. In one exemplary embodiment, the metal-containing film includes an organic substance. In one exemplary embodiment, the first processing gas comprises at least one selected from the group consisting of fluorocarbon gas, hydrofluorocarbon gas, NF3 gas, and SF6 gas. In one exemplary embodiment, the second treatment gas includes a chlorine-containing gas. In one exemplary embodiment, the chlorine-containing gas is BCl3 gas or Cl2 gas. In one exemplary embodiment, the first processing gas includes at least one selected from the group consisting of O₂ gas, CO gas, and CO₂ gas. In one exemplary embodiment, the first treatment gas further comprises a chlorine-containing gas. In one exemplary embodiment, the chlorine-containing gas is at least one selected from the group consisting of Cl₂ gas, BCl₃ gas, and SiCl₄ gas. In one exemplary embodiment, step (c) alternately repeats the process of generating a second plasma using a gas containing hydrogen and nitrogen as a second process gas, and generating a second plasma using a gas containing chlorine as the second process gas. In one exemplary embodiment, the film to be etched is a Si-containing film or a carbon-containing film. In one exemplary embodiment, the process includes, after step (c), etching the film to be etched using the metal-containing film (d) as a mask. In one exemplary embodiment, steps (a) through (d) are performed within the same chamber. In one exemplary embodiment, the metal-containing film comprises a metal-containing photoresist film, where the first region is an exposed region of the metal-containing photoresist film, and the second region is an unexposed region of the metal-containing photoresist. In one exemplary embodiment, the first region is exposed to EUV light. In one exemplary embodiment, a plasma processing system is provided comprising a chamber, a substrate support section provided within the chamber, and a control section, wherein the control section executes the following controls: (a) a control for preparing a substrate having a film to be etched and a metal-containing film provided on the film to be etched, on the substrate support section, wherein the metal-containing film has an exposed first region and an unexposed second region; (b) a control for modifying the metal-containing film using a first plasma generated from a first processing gas containing either a fluorine-containing gas or an oxygen-containing gas; and (c) a control for selectively removing the first region of the modified metal-containing film relative to the second region using a second plasma generated from a second processing gas. The embodiments of this disclosure will be described in detail below with reference to the drawings. In each drawing, identical or similar elements are denoted by the same reference numeral, and redundant explanations are omitted. Unless otherwise specified, positional relationships (up, down, left, right, etc.) are described based on the positional relat