Evaluation of Evaporated ZnxPb1 − x S as a Gate Insulator for HgCdTe Metal‐Insulator‐Semiconductor (MIS) Devices

Abstract

The physical and electrical characteristics of dielectric layers deposited by the coevaporation of and have been studied. The films were nearly amorphous with uniform compositions. Capacitance‐voltage (C‐V) and current‐voltage (I‐V) measurements have been made on metal‐insulator‐semiconductor (MIS) capacitors fabricated on n‐type. The gate insulators were 200 nm thick and had 0, 4, or 8 atomic percent . Introduction of Pb into the dielectric resulted in an increase in the leakage current through the insulator and an increase in the amount of charge trapped at the insulator/semiconductor interface compared to . The capacitances of the Pb‐containing MIS devices in accumulation were functions of the measurement frequencies. The increase in the leakage current and the dispersion in the measured capacitance were caused by traps within the bulk of the dielectric. The increased charge trapping was attributed to the formation of a thin, nonstoichiometric layer at the interface.