The interfacial properties of AOF/ZnS and LWIR bulk HgCdTe materials by MIS structures

Abstract

The semiconductor-passivating layer interface, as well as the dielectric properties of the passivants, plays an important role in HgCdTe based photoelectric detectors. Anodization is a commonly uses surface passivation for HgCdTe. ZnS is deposited on the AOF (anodic-oxide film) as antireflecting layer. The interfacial properties of the metal insulator semiconductor (MIS) structures were determined by capacitance-voltage (C-V) measurements in the frequency range 10 KHz-10 MHz. The results showed that the MIS detector could not reach the high frequency level even at frequencies up to 10 MHz. The interfacial state densities were 3.4×10 11 cm -2 q -1 V -1 and the fixed charges were 1.1×10 12 cm -2 . The surface recombination velocity was 700 cm/s.