Characterization study of CdS passivation layers on HgxCd1-xTe

HgxCd1-xTe epitaxial samples were passivated using an anodic non-aqueous sulphidation technique. The chemical composition and thickness of the CdS thin films deposited were investigated by selected-area X-ray photoelectron spectroscopy combined with Ar+ ion sputtering. The CdS films formed on HgxCd1-xTe were found to be nearly stoichiometric; their thickness varied with the sulphidation temperature and time. The lateral non-homogeneity of the CdS passivation layers was studied by means of scanning Auger microscopy. The chemical composition and origin of the ''holes'' observed in the CdS films deposited were revealed by the Auger chemical images obtained.