CROSS-REFERENCE TO RELATED APPLICATION

This application is based on and claims priority from Japanese Patent Application Nos. 2018-140334 and 2019-104041, filed on Jul. 26, 2018 and Jun. 3, 2019 with the Japan Patent Office, respectively, the disclosures of which are incorporated herein in their entireties by reference.

TECHNICAL FIELD

The following disclosure relates to a plasma processing method and a plasma processing apparatus.

BACKGROUND

A plasma-enhanced atomic layer deposition (PE-ALD) method is known as a kind of method for forming a film on a substrate. Various techniques, including the PE-ALD method, are used to form a pattern in the semiconductor devices.

For example, there has been proposed a method using ALD such that film formation is selectively promoted according to the position of an opening formed in a substrate (US Patent Laid-Open Publication No. 2017/0140983). In addition, there has been proposed a method of selectively forming a self-assembled monolayer (SAM) and then performing gas phase etching (US Patent Laid-Open Publication No. 2017/0148642). Furthermore, there has been proposed a method for implementing selective film formation on a 3D nanostructure using ion implantation (Woo-Hee Kim, et al., “A Process for Topographically Selective Deposition on 3D Nanostructures by Ion Implantation” ACS Nano 2016, 10, 4451-4458).

SUMMARY

A plasma processing method performed by a plasma processing apparatus according to an aspect of the present disclosure includes a first step and a second step. In the first step, the plasma processing apparatus forms a first film on the side walls of an opening in a processing target, in which the first film has different thicknesses along a spacing between pairs of side walls facing each other. In the second step after the first step, the plasma processing apparatus performs a film forming cycle once or more times to form a second film having different thicknesses along the spacing between the pairs of side walls facing each other.

The foregoing summary is illustrative only and is not intended to be in any way limiting. In addition to the illustrative aspects, exemplary embodiments, and features described above, further aspects, exemplary embodiments, and features will become apparent by reference to the accompanying drawings and the following detailed description.

