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JP-2026074820-A - Film forming method

JP2026074820AJP 2026074820 AJP2026074820 AJP 2026074820AJP-2026074820-A

Abstract

[Problem] To provide a technology that can selectively form a silicon-containing film on the bottom surface of each of a plurality of recesses having different opening widths. [Solution] A film formation method according to one aspect of the present disclosure comprises: preparing a substrate having a plurality of recesses having different opening widths; forming a silicon-containing film along the surface of the plurality of recesses; filling the inside of the plurality of recesses where the silicon-containing film is formed with a carbon-containing film; exposing the silicon-containing film formed on the upper part of the plurality of recesses from the carbon-containing film by performing anisotropic etching of the carbon-containing film in the thickness direction of the substrate; and removing the silicon-containing film exposed from the carbon-containing film by etching the silicon-containing film using the carbon-containing film as an etching mask. [Selection Diagram] Figure 1

Inventors

  • 本山 豊
  • 藤川 尋斗
  • バス トウヒン シュブラ

Assignees

  • 東京エレクトロン株式会社

Dates

Publication Date
20260507
Application Date
20241021

Claims (8)

  1. Prepare a substrate in which multiple recesses with different opening widths are formed, Forming a silicon-containing film along the surface of the multiple recesses, The plurality of recesses in which the silicon-containing film is formed are filled with a carbon-containing film, By performing anisotropic etching on the carbon-containing film in the thickness direction of the substrate, the silicon-containing film formed on the upper part of the plurality of recesses is exposed from the carbon-containing film. By etching the silicon-containing film using the carbon-containing film as an etching mask, the silicon-containing film exposed from the carbon-containing film is removed. A film formation method having the following characteristics.
  2. The embedding with the carbon-containing film includes forming the carbon-containing film so as to cover the entire silicon-containing film formed along the surface of the plurality of recesses. The method for forming a film according to claim 1.
  3. The act of filling with the carbon-containing film includes completely filling the multiple recesses with the carbon-containing film. The method for forming a film according to claim 1.
  4. Exposing the carbon-containing film includes supplying oxygen plasma to the carbon-containing film. The method for forming a film according to claim 1.
  5. Removing the silicon-containing film includes supplying a fluorine-containing gas to the silicon-containing film. The method for forming a film according to claim 1.
  6. The carbon-containing film is removed from the plurality of recesses from which the silicon-containing film has been removed, The process involves supplying a germanium-containing gas into the plurality of recesses from which the carbon-containing film has been removed, and forming a germanium-containing film on the silicon-containing film remaining in the plurality of recesses. Having, The method for forming a film according to claim 1.
  7. The silicon-containing film is an amorphous silicon film. A method for forming a film according to any one of claims 1 to 6.
  8. The carbon-containing film is a spin-on carbon film. A method for forming a film according to any one of claims 1 to 6.

Description

This disclosure relates to a method for forming thin films. Patent Document 1 discloses a technique for growing a silicon film from the bottom of a recess toward the opening. In Patent Document 1, a silicon film is formed throughout the recess; then, the silicon film on the upper part of the inner wall of the recess is removed by etching using chlorine gas, while leaving the silicon film on the bottom surface of the recess; and finally, a silicon film is selectively formed on the silicon film remaining on the bottom surface of the recess. Japanese Patent Publication No. 2019-197872 This is a flowchart showing the film deposition method according to the embodiment.This is a cross-sectional view (1) showing the film deposition method according to the embodiment.This is a cross-sectional view (2) showing the film formation method according to the embodiment.This is a cross-sectional view (3) showing the film deposition method according to the embodiment.This is a cross-sectional view (4) showing the film deposition method according to the embodiment.This is a cross-sectional view (5) showing the film formation method according to the embodiment.This is a cross-sectional view (6) showing the film formation method according to the embodiment.This is a cross-sectional view (7) showing the film formation method according to the embodiment. The following describes exemplary embodiments of this disclosure, not limited to those described herein, with reference to the attached drawings. In all attached drawings, identical or corresponding members or components are denoted by the same or corresponding reference numerals, and redundant descriptions are omitted. [Film formation method] The film deposition method according to the embodiment will be described with reference to Figures 1 to 8. Figure 1 is a flowchart showing the film deposition method according to the embodiment. Figures 2 to 8 are cross-sectional views showing the film deposition method according to the embodiment. The film deposition method according to the embodiment has steps S11 to S17 shown in Figure 1. In step S11, the substrate 100 is prepared as shown in Figure 2. The substrate 100 has a silicon substrate 110. The surface of the silicon substrate 110 is provided with a plurality of recesses 120 having different opening widths. In the example in Figure 2, the surface of the silicon substrate 110 is provided with a recess 120a having a first opening width W1 and a recess 120b having a second opening width W2. The second opening width W2 is wider than the first opening width W1. Recesses 120a and 120b are, for example, trenches. In this specification, recesses 120a and 120b are collectively referred to as recesses 120. A silicon oxide film 130 is provided on the surface of the recesses 120. The silicon oxide film 130 is an example of an insulating film. In step S12, as shown in Figure 3, a silicon film 140 is formed along the surface of the multiple recesses 120. In step S12, the silicon film 140 may be formed to cover the surface of the silicon oxide film 130. In step S12, the silicon film 140 may be formed so that the openings of each of the multiple recesses 120 are not blocked. The silicon film 140 is amorphous. The silicon film 140 is undoped. For example, the silicon film 140 can be formed by chemical vapor deposition (CVD) using a silicon source gas. The silicon film 140 is an example of a silicon-containing film. In step S13, as shown in Figure 4, the carbon film 150 is used to fill the recesses 120. In step S13, the carbon film 150 may be formed to cover the entire silicon film 140 formed along the surface of the recesses 120. Alternatively, the carbon film 150 may be formed to completely fill the recesses 120. For example, the carbon film 150 is a spin-on carbon film. In this case, it is easier to fill the recesses 120 with the carbon film 150. The carbon film 150 is an example of a carbon-containing film. In step S14, as shown in Figure 5, anisotropic etching is performed on the carbon film 150 in the thickness direction of the substrate 100, thereby exposing the silicon film 140 formed on the upper part of the multiple recesses 120 from the carbon film 150. In step S14, the silicon film 140 formed on the upper part of the recesses 120 and the upper part of the sides of the recesses 120 may be exposed from the carbon film 150 without exposing the silicon film 140 formed on the bottom and lower side surfaces of the recesses 120. For example, by supplying oxygen plasma to the substrate 100, the silicon film 140 formed on the upper part of the multiple recesses 120 can be exposed from the carbon film 150. When using oxygen plasma, it is easier to remove the carbon film 150 formed on the top and side surfaces of the recesses 120 without removing the carbon film 150 formed on the bottom surface of the recesses 120. However, by supplying hydrogen plasma to the substrate 100, the silicon film 140 formed on the upper part of the multiple recesses 1