Abstract

BaTiO3 (BT) thin films were prepared by flash evaporation onto p-Si and SiO2/p-Si. The films are amorphous and remain so after a thickness reduction by 20% by annealing at 500 °C for 3 min. in O2 atmosphere. The electrical characteristics were measured at room temperature. Electron injection at the Al to BT interface of Al/BT/Si capacitors is enhanced by the Schottky effect, yielding a value of 11.2 for the dielectric constant of BT. Modeling current-time measurements yields a trap density of 1024 m-3, 0.82 eV below the conduction band. Capacitance-voltage curve shifts due to bias stress on Al/BT/SiO2/Si capacitors are interpreted as caused by electron injection and trapping in the BT films. Starting deposition at 170 °C or post-deposition annealing reduces the trap density and increases the C-V curve shifts by bias stress, from 0.3 to over 14 V at bias stress of -10 V.