Dynamically adjusted purge timing in wet atomic layer etching

Abstract

The present disclosure provides various embodiments of an improved wet atomic layer etching (ALE) process. More specifically, the present disclosure provides various embodiments of methods that improve a wet ALE process by providing a dynamic ALE cycle timing schedule that balances throughput and etch rate with post-etch surface roughness. As described in more detail below, the methods disclosed herein may adjust the purge timing between ALE cycles and/or between individual surface modification and selective dissolution steps to provide a desired throughput, etch rate and/or post-etch surface roughness in a wet ALE process.