Investigation of passivation processes for HgCdTe/CdS structure for infrared application

The effect of chemical and in-situ electrochemical etching on the morphology of the mercury cadmium telluride (HgCdTe) surface, prior to growth of the cadmium sulfide (CdS) films, has been examined. The CdS films have also been characterized using grazing angle X-ray diffraction and optical absorption spectroscopy. Preferential growth of (002) planes of CdS has been observed on the HgCdTe substrate. The effectiveness of the surface treatment and CdS growth methodology for passivation of the HgCdTe surface has been examined using capacitance-voltage studies of Au/HgCdTe/CdS/Au devices at 77 K. A negative fixed charge density ∼ 1015/m2 was obtained.