Electrical properties of ZnS having been used as antireflection layer and surface passivation layer of HgCdTe are investigated.
ZnS film on HgCdTe is annealed with condition of several temperatures in the atmosphere so that it is denser but it is not much changed.
Even though ZnS on Si is very good insulator, ZnS on HgCdTe is very poor. But the uncomfortable property is removed by development of MULTI-LAYER structure. Three-layer structure reducible the time required for evaporation having key property of multi-layer structure.
And then ZnS with the structure is exposed in hydrogen sulfide atmosphere for reproducibility and uniformity. ZnS film obtained by that method has at least the resistivity of $10^8$[Ω-cm].
The interface properties of ZnS-HgCdTe is characterized by Nickel-ZnS-HgCdTe(MIS) capacitor.
From capacitanece-voltage curve of MIS capacitor fabricated using the two surface passivation methods, Zns fixed charge, ZnS trapped charge, and interface trapped charge are extracted. Results show that both have good interface.
The surface mobility of the n-channel MISFET fabricated using ZnS as gate insulator is 2814 [$cm^2V^{-1}s^{-1}$] and the threshold voltage of that is 7.5 [V].
