Depth profile of fixed charge in epitaxial oxide films on silicon substrate for MFIS structure

The depth profiles of fixed charges in heteroepitaxial SrTiO₃/CeO₂/yttria-stabilized zirconia(YSZ)/Si and SrTiO₃/MgO/Si structures were investigated using the capacitance-voltage (C-V) measurement of the films with slanted thickness. The heterostructures with slanted thickness were fabricated by pulsed laser deposition (PLD) using in-situ masking technique. It was found that there are negative fixed charges in both films. From the equivalent oxide thickness dependence of the mid-gap voltage, it was clarified that these negative charges are located at the interface between layers and near the ultra thin layer on Si.