Trends in Reverse-Current Change in Tunnel MIS Diodes with Calcium Fluoride on Si(111) Upon the Formation of an Extra Oxide Layer

Abstract

The currents flowing in metal–CaF₂–n-Si and metal–SiO₂–CaF₂–n-Si structures with the same (about 1.5 nm) fluoride thickness are compared in the reverse-bias mode. It is revealed that the current in the case of a two-layer dielectric can be notably higher within a certain voltage range. Such unexpected behavior is associated with the coexistence of both electron and hole components of the current as well as with the configuration of the SiO₂–CaF₂ barrier through which tunneling occurs. The results of measurements and explanatory simulation data are presented.