Metal-ferroelectric-insulator-semiconductor (MFIS) structures including an Al2O3 insulator layer and a SET ferroelectric film are fabricated with their optimum thicknesses extracted by computer simulation, and then electrical properties of MFIS structures are investigated. In Pt/Al2O3/Si structure, no hysteresis and low leakage current of 7.5x10(-9)A/cm(2) have been observed. The MRS structure, Pt/SBT/Al2O3/Si, shows a memory window width of 1.2 V at an operation voltage of 5 V and a gate leakage current density of 7x10(-8)A/cm(2) at 1 V. Fatigue characteristics of the MFIS structure are also studied.