Characteristics of Metal/Ferroelectric/Insulator/Semiconductor Using La2O3 Thin Film as an Insulator

We fabricated a novel metal/ferroelectric/insulator/semiconductor (MFIS) structure using the PbTiO3 film and La2O3 film prepared by metal organic chemical vapor deposition as a ferroelectric and an insulator, respectively. The dielectric constant (k) of the 420 Å La2O3 film was about 28. The leakage current density was about 3×10-6 A/cm2 at +5 V. The MFIS using an Al/PbTiO3 (3600 Å)/La2O3 (280 Å)/Si configuration showed clockwise C–V hysteresis. The memory window increased from 0.3 to 2.6 V with increasing bias from 2 to 10 V. In this letter we propose the La2O3 film as an alternative insulator layer in the MFIS structure.