Preparation and Properties of Bi2SiO5/Si Structures

Bismuth silicate (Bi2SiO5) films, expected as the intermediate buffer layer between the bismuth layer-structured ferroelectrics (BLSF) and silicon substrate, were prepared on (100)-oriented silicon wafers by rf magnetron sputtering. The c-axis-oriented Bi2SiO5 films with smooth surface morphology were obtained at the substrate temperature of 400°C. The leakage current density is on the order of 10-10 A·cm-2, under the applied electric field of less than 350 kV·cm-1. From capacitance–voltage characteristics measurement results, it is worth noting 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 metal-ferroelectric-insulator-semiconductor (MFIS) capacitor can be reversed at a low applied voltage. This suggests that Bi4Ti3O12/Bi2SiO5/Si structures are suitable for application for ferroelectric memory devices.