The effect of band offset on the retention properties of metal-ferroelectric (PbZr0.53Ti0.47O3)-insulator (Dy2O3,Y2O3)-semiconductor capacitors and field effect transistors

Metal-ferroelectric-insulator-semiconductor field effect transistors (MFISFETs) and capacitors with the structures of Al∕Pb (Zr0.53,Ti0.47) O3 (PZT)∕Dy2O3∕Si and Al∕PZT∕Y2O3∕Si were fabricated. The variation of the memory window as a function of annealing temperature was studied. The maximum capacitor-voltage (C-V) memory window of Al∕PZT∕Dy2O3∕Si capacitors was 2.95V. The retention times of Al∕PZT∕Y2O3∕Si and Al∕PZT∕Dy2O3∕Si MFISFETs were 11.5days and 11.1h, respectively. The longer retention time of Al∕PZT∕Y2O3∕Si MFISFETs is attributed to the larger conduction band offset at the Y2O3∕Si interface (2.3eV) compared to that of Dy2O3∕Si (0.79eV).