Fabrication and properties of Bi₂SiO₅ thin films for MFIS structures

Bismuth silicate (Bi₂SiO₅) thin films expected as the intermediate buffer layer for metal-ferroelectric-insulator-semiconductor (MFIS) structures were fabricated on Si(100) wafers by rf magnetron sputtering. It was confirmed that the resultant films were single phases Bi₂SiO₅ with c-axis dominant orientated. The relative dielectric constant was estimated to be approximately 14. The leakage current density of the metal-insulator-semiconductor (MIS) diode is on the order of 10^-10 A cm^-2, under the applied electric field of less than 350 kV cm^-1. In the capacitance-voltage (C-V) characteristics measurement results, it is worth nothing that hysteresis is hardly observed. The interface trap density at the midgap is estimated to be approximately 6×10¹² cm^-2 eV^-1. The numerical evaluation results indicate that the MFIS capacitor can be reversed at a low applied voltage.