In the present study, Ta/La2O3 ¯lms (La2O3 doped with Ta2O5 Þ as a gate dielectric were prepared using a sol–gel method at low pressure. Ta/La2O3 ¯lm has some hopeful properties as a gate dielectric of logic device. The structure and morphology of Ta/La2O3 ¯lms were studied using X-ray di®raction (XRD), atomic force microscopy (AFM) and scanning electron microscopy (SEM). Electrical properties of ¯lms were performed using capacitance–voltage (C–V Þ and current density-voltage (J–V Þ measurements. The optical bandgap of samples was studied by UV-visible optical absorbance measurement. The optical bandgap, Eopt, is determined from the absorbance spectra. The obtained results show that Ta/La2O3 ¯lm as a good gate dielectric has amorphous structure, good thermal stability, high dielectric constant ð 25Þ, low leakage current and wide bandgap ð 4:7 eVÞ.
