Atomic layer etching of InP using a low angle forward reflected Ne neutral beam

In this study, the atomic layer etching characteristics and the etch mechanism of (100) InP as functions of Cl2 pressure and Ne neutral beam irradiation dose were investigated. When Cl2 pressure and Ne neutral beam irradiation dose were lower than the critical values of 0.4mTorr and 7.2×1015at.∕cm2cycle, respectively, the InP etch rate (Å/cycle) and the InP surface roughness varied with Cl2 pressure and Ne neutral beam irradiation dose. However, when the Cl2 pressure and Ne neutral beam irradiation dose were higher than the critical values, the InP etch rate remained as 1.47Å∕cycle, corresponding to one monolayer per cycle, and the surface roughness and the surface stoichiometry remained similar to those of InP before etching.