Patent ID: 11915941
Assignee: TOKYO ELECTRON LIMITED
Field: Semiconductors (Electrical engineering)
Classification: CPC H | IPC H

Claim 0:
1. A method of etching a substrate using a wet atomic layer etching (ALE) process, the method comprising:
receiving the substrate, the substrate having a material exposed; and
selectively etching the material by performing multiple cycles of the wet ALE process, wherein each cycle comprises:
a) performing one or more surface modification steps to chemically modify an exposed surface of the material and provide a modified surface layer, wherein the one or more surface modification steps includes exposing the exposed surface of the material to at least one surface modification solution to chemically modify the exposed surface of the material;
b) performing a first purge step after the one or more surface modification steps, wherein the first purge step includes rinsing the substrate with a solvent;
c) performing a dissolution step after the first purge step to selectively remove the modified surface layer of the material, wherein the dissolution step includes exposing the modified surface layer to a dissolution solution to dissolve the modified surface layer; and
d) performing a second purge step after the dissolution step, wherein the second purge step includes rinsing the substrate with a solvent or performing a spin dry step; and

adjusting a purge time of the first purge step and/or a purge time of the second purge step during one or more cycles of the wet ALE process to provide a desired throughput, etch rate and/or post-etch surface roughness in the wet ALE process.