Characterization of Wet Chemical Atomic Layer Etching of InGaAs

In this work, we characterized the wet chemical atomic layer etching of an InGaAs surface by using various surface analysis methods. For this etching process, H2O2 was used to create a self-limiting oxide layer. Oxide removal was studied for both HCl and NH4OH solutions. Less In oxide tended to remain after the HCl treatment than after the NH4OH treatment, so the combination of H2O2 and HCl is suitable for wet chemical atomic layer etching. In addition, we found that repetition of this etching process does not impact on the oxide amount, surface roughness, and interface state density. Thus, nanoscale etching of InGaAs with no impact on the surface condition is possible with this method.