Reduction of Process-induced damage in atomic layer etching

Atomic layer etching (ALE) involves performing self-limited etching at the atomic layer level by repeating each step of the surface adsorption and desorption. ALE enables atomic-precision control of the surface reaction and low damage etching of the underlying layer in device fabrication. We have previously investigated ALE of SiN with process optimization of the surface adsorption and desorption steps, and we achieved stable ALE by controlling the precise surface conditions. In this study, we investigated the damage by ALE on SiN and clarified the mechanism of damage generation, to facilitate low damage etching in ALE.