Fabrication and properties of Bi/sub 2/SiO/sub 5/ thin films for MFIS structures

Bismuth silicate (Bi/sub 2/SiO/sub 5/) thin films, expected to be suitable 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 phase Bi/sub 2/SiO/sub 5/ with c-axis dominant orientation. 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/sup -10/ A cm/sup -2/. under an applied electric field of less than 350 kV cm/sup -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 /spl times/ 10/sup 12/ cm/sup -2/ eV/sup -1/. The numerical results indicate that the MFIS capacitor can be reversed at a low applied voltage.