In this atomic-scale study on technologically relevant group IV semiconductors, Ge and SiGe, we relate surface chemistry, in particular the nature of surface oxides, to wet etching kinetics. ICP-MS quantification of Ge in HCl solution containing H2O2 as the oxidizing agent showed that the Si bulk concentration strongly impacted the etching kinetics. Post operando synchrotron XPS provided insight into the surface oxide chemistry involved in the etching process: a non-homogeneous porous layer with a depletion of Ge components at the outer surface due to pull out effects.
Role of quantum confinement in luminescence efficiency of group IV nanostructures