US-12618156-B2 - Atomic layer deposition of silicon nitride film using helium gas plasma

US12618156B2US 12618156 B2US12618156 B2US 12618156B2US-12618156-B2

Abstract

A substrate processing method includes forming an adsorption layer on a substrate by supplying a silicon-containing gas to the substrate; performing a modification by generating plasma containing He; and generating plasma of a reaction gas to cause the plasma to react with the adsorption layer, wherein the forming the adsorption layer, the performing the modification, and the generating the plasma are repeated to form a silicon-containing film.

Inventors

Munehito KAGAYA

Assignees

TOKYO ELECTRON LIMITED

Dates

Publication Date: 20260505
Application Date: 20201112
Priority Date: 20191119

Claims (10)

1 . A substrate processing method comprising: (a) forming an adsorption layer on a substrate by supplying a silicon-containing gas to the substrate; (b) after (a), modifying the adsorption layer by plasma of He gas; and (c) after (b), nitriding the modified adsorption layer by causing the modified adsorption layer to react with plasma of a nitrogen-containing reaction gas, wherein (a), (b), and (c) are repeated to form a silicon nitride film.
2 . The substrate processing method of claim 1 , further comprising: purging the silicon-containing gas between (a) and (b).
3 . The substrate processing method of claim 2 , wherein, in (b) the adsorption layer, the adsorption layer is modified by being exposed to at least one of He ions in the plasma, He radicals in the plasma, and a light emission of the plasma containing He.
4 . The substrate processing method of claim 3 , wherein (b) improves an etching resistance of the silicon nitride film.
5 . The substrate processing method of claim 3 , wherein the silicon-containing gas includes at least one gas selected from a group consisting of a DCS gas, a SiH 4 gas, a trisilylamine (TSA) gas, a silicon-based gas containing a halogen, and an aminosilane gas.
6 . The substrate processing method of claim 5 , wherein the reaction gas includes at least one gas selected from a group consisting of a NH 3 gas, a N 2 gas, hydrazine, and a hydrazine derivative gas.
7 . The substrate processing method of claim 1 , wherein, in (b), the adsorption layer is modified by being exposed to at least one of He ions in the plasma, He radicals in the plasma, and a light emission of the plasma containing He.
8 . The substrate processing method of claim 1 , wherein (b) improves an etching resistance of the silicon nitride film.
9 . The substrate processing method of claim 1 , wherein the silicon-containing gas includes at least one gas selected from a group consisting of a DCS gas, a SiH 4 gas, a trisilylamine (TSA) gas, a silicon-based gas containing a halogen, and an aminosilane gas.
10 . The substrate processing method of claim 1 , wherein the reaction gas includes at least one gas selected from a group consisting of a NH 3 gas, a N 2 gas, hydrazine, and a hydrazine derivative gas.

Description

CROSS-REFERENCE TO RELATED APPLICATIONS The present application is a U.S. National Stage Entry of International Patent Application No. PCT/JP2020/042215, filed Nov. 12, 2020, which claims the benefit of priority to Japanese Patent Application No. 2019-209033, filed Nov. 19, 2019, each of which is hereby incorporated herein by reference in its entirety. TECHNICAL FIELD The present disclosure relates to a substrate processing method and a substrate processing apparatus. BACKGROUND A SiN film is formed by, for example, an ALD method using plasma. A low wet etching rate is required for the SiN film. Patent Document 1 discloses a method of forming a SiN film in which adsorbing a film precursor containing Si on a semiconductor substrate, exposing the adsorbed film precursor to plasma containing N-containing ions and/or radicals to form a SiN coating film layer, and increasing the density of the SiN film layer by exposing plasma containing He to the SiN film layer are repeated. PRIOR ART DOCUMENT [Patent Document] Patent Document 1: Japanese Patent Publication No. 2016-066794 SUMMARY However, a modifying process using the He gas plasma disclosed in Patent Document 1 has a problem in that a film formation rate is reduced. In an aspect, the present disclosure provides a substrate processing method and a substrate processing apparatus that improve a film formation rate. In view of the foregoing, according to an aspect, there is provided a substrate processing method which includes forming an adsorption layer on a substrate by supplying a silicon-containing gas to the substrate; performing a modification by generating a He-containing plasma; and generating plasma of a reaction gas to cause the plasma to react with the adsorption layer, wherein the forming the adsorption layer, the performing the modification, and the generating the plasma are repeated to form a silicon-containing film. According to an aspect, it is possible to provide a substrate processing method and a substrate processing apparatus that improve a film formation rate. BRIEF DESCRIPTION OF DRAWINGS FIG. 1 is a schematic view illustrating a configuration example of a substrate processing apparatus. FIG. 2 is a time chart illustrating an example of an operation of the substrate processing apparatus according to the present example. FIG. 3 is a time chart illustrating an example of an operation of a substrate processing apparatus according to a reference example. FIG. 4 is a graph showing an example of comparison between film qualities of a SiN film of the present example, a SiN film of the reference example, and a SiN film in a case of no modification. FIG. 5 is a graph showing an example of a relationship between a WERR and an RI. FIG. 6 is a graph showing an example of a dependence of an amount of Si-N bonds contained in the SiN film on a He plasma exposure time in the SiN film of the present example. FIG. 7 is a graph showing an example of a dependence of an amount of N-H bonds contained in the SiN film on the He plasma exposure time in the SiN film of the present example. DETAILED DESCRIPTION Hereinafter, embodiments of the present disclosure will be described with reference to the accompanying drawings. In each of the drawings, the same components will be denoted by the same reference numerals, and redundant descriptions thereof may be omitted. [Substrate Processing Apparatus] A substrate processing apparatus 101 according to an embodiment will be described with reference to FIG. 1. FIG. 1 is a schematic view illustrating a configuration example of the substrate processing apparatus 101. The substrate processing apparatus 101 forms a SiN film by a plasma enhanced atomic layer deposition (PE-ALD) method within a processing container maintained in a depressurized state. As illustrated in FIG. 1, the substrate processing apparatus 101 includes a processing container 1, a stage 2, a shower head 3, an exhauster 4, a gas supply mechanism 5, an RF power supply 8, and a controller 9. The processing container 1 is made of a metal such as aluminum, and has a substantially cylindrical shape. The processing container 1 accommodates a wafer W. A carry-in/out port 11 for carrying in or carrying out the wafer W therethrough is formed in the sidewall of the processing container 1. The carry-in/out port 11 is opened/closed by a gate valve 12. An annular exhaust duct 13 having a rectangular cross section is provided on a main body of the processing container 1. A slit 13a is formed along an inner peripheral surface of the exhaust duct 13. An exhaust port 13b is formed in an outer wall of the exhaust duct 13. On a top surface of the exhaust duct 13, a ceiling wall 14 is provided to close an upper opening of the processing container 1 via an insulator member 16. A space between the exhaust duct 13 and the insulator member 16 is hermetically sealed with a seal ring 15. A partition member 17 partitions the interior of the processing container 1 into upper and lower port