We have investigated the impact of different
wet treatments on the electrical performances of germanium?
tin (GeSn)-based p-MOS capacitors with 10% Sn. Atomic
force microscopy (AFM) showed the presence of Sn droplets
for the degreased Ge0.9Sn0.1 surface, which were removed by
HCl, HF, and HF:HCl treatments. On the other hand,
(NH4)2S and NH4OH treatments were not fully able to
remove these droplets. X-ray photoelectron spectroscopy
(XPS) measurements confirmed AFM results and highlighted
the efficiency of HF, HCl, and HF:HCl treatments in
removing Ge and Sn native oxide, which was not the case
with (NH4)2S and NH4OH. Nevertheless, XPS showed a reoxidation of ...