Atomic Layer Etching (ALE) transitioned to manufacturing because of unique performance benefits which come from self-saturation of the steps and the use of very low ion energies or just thermal means to remove material. The former property gives uniformity across all lengths scales on the wafer. Reduced aspect ratio dependent etching (ARDE) and surface smoothness are very attractive benefits. Low level removal energies deliver selectivity which is a key requirement for etching with atomic scale fidelity.

In this talk, a conceptual framework for directional and isotropic ALE will be compared to other etching technologies for semiconductor devices. Recent experimental and theoretical results as well as applications examples will be presented to illustrate the concepts.