We have studied the surface cleaning of Sb-based compound semiconductors using HF, NH4OH, and HCl cleans and the metal oxide semiconductor (MOS) capacitors fabricated subsequently. GaSb, InGaSb, and AlGaSb surfaces are investigated using low-energy radiation from the synchrotron. Capacitance voltage (C V) and photoluminescence measurements are carried out on capacitors made with Al2O3 from atomic layer deposition and corroborated with the results from synchrotron spectroscopy. Excellent C V characteristics with ...