Interface electrical characteristics of passivation films on HgCdTe

A new passivation film: evaporated CdTe/ZnS combination film was grown on HgCdTe and the interface was characterized by Capacitance-Voltage(CV) characteristics of Metal-Insulator-Semiconductor(MIS) test structures. Under proper processing conditions, the interface electrical parameters are: density of fixed charge similar to-4.0 x 10(10) cm(-2), density of slow state similar to 5.1 x 10(10) cm(-2), density of fast interface state similar to 2.7 x 10(11) cm(-2)eV(-1), and the time stability is good. These results show CdTe/ZnS double layer film is suitable for passivation of HgCdTe infrared detectors. We have also investigated single layer ZnS and anodic oxide/CdTe/ZnS triple layer film and found that the time stability of ZnS isn't good, and there exists too high density of fixed positive charge at the triple layer film/HgCdTe interface.