Atomic Layer Etching - Methods

Here is an overview of the differring approaches to reach atomic scale precision:
ALE table

Challenges of Tailoring Surface Chemistry and Plasma/Surface Interactions to Advance Atomic Layer Etching

S. U. Engelmann, R. L. Bruce, M. Nakamura, D. Metzler, S. G. Walton, E. A. Joseph
Ecs Journal of Solid State Science and Technology 4(6), N5054-N5060, 2015



 One of the most important things to note is that only a small window exsists for any process to achieve atomic scale precision.

A schematic, mostly geared towards the flux control approach can be seen here:

 ALE window

 It should be noted, that of course E0 is a function of the plasma system that is being used, whereas ES is a function of the material to be etched. Based on the plasma/material system chosen, the range of these can differ greatly.