Atomic layer etching of Si(100) and Si(111) using Cl₂ and Ar neutral beam

Atomic layer etching of Si(100) and Si(111) was carried out using Cl ₂ adsorption followed by the Ar neutral beam irradiation for the removal of charging damage during the etching. By supplying Cl₂ and Ar neutrals higher than the critical doses, the exact same depth per cycle corresponding to one atomic layer per cycle of 1.36 Å/cycle for silicon (100) and 1.57 Å/cycle for silicon (111) could be obtained by a self-limited etching mechanism. The critical Cl₂ pressure and Ar neutral beam irradiation time corresponded to one monolayer chemisorption of chlorine by the dissociative Langmuir isotherm and the irradiation of Ar neutral beam was enough to remove one layer of silicon chloride formed on the silicon surfaces, respectively.