Epitaxial growth of thin Ca$_{1-x}$Ba$_x$F$_2$ films on Si(111) and study of electro-physical characteristics of Ca$_{1-x}$Ba$_x$F$_2$ – based metal–insulator–semiconductor structures

In the context of searching for alternative insulators for Silicon-based electronics, beyond mainstream high-$k$ oxides, planar Ca$_{1-x}$Ba$_x$F$_2$ films with a 2–4 nm nominal thickness and various stoichiometric composition were grown on the $n$-Si (111) wafers. The current-voltage characteristics of the Al-gated MIS capacitors (Al/fluoride/Si) were recorded. Qualitatively, a behavior of these devices agreed to that predicted for MIS (metal–insulators–semiconductor) tunneling systems. Similar behavior of the I–V characteristics was revealed for different values of the parameter $x$, but the spread of characteristics was smaller at $x$ = 0.25. In the future, Ca$_{1-x}$Ba$_x$F$_2$ solid solutions can be used for gate dielectrics of field-effect transistors with various topologies.