Admittance measurements of metal–insulator–semiconductor devices in p‐type HgCdTe

Measured capacitance and dynamic conductance characteristics of metal–insulator–semiconductor (MIS) devices as a function of gate bias, frequency, and temperature are reported. The results demonstrate the quality of the interface for the realization of photodiodes and MIS devices on p‐type HgCdTe. The measured small‐signal dynamic resistance of the p‐type semiconductor is compared with the R0 A product of photodiodes fabricated on the same substrates. The correlation between the measured R0 A of the substrate and the R0 A of the photodiodes suggests that the R0 A product is essentially determined by the substrate. The temperature dependence of the R0 A of the substrates, as determined from the MIS devices, shows that both diffusion and generation–recombination mechanisms contribute to the dark current in p‐type Hg1−x Cdx Te with x=0.2. This is in contrast to n+ p photodiodes where the dominant mechanism is diffusion.