Electrical properties of low temperature deposited amorphous barium titanate thin films as dielectrics for integrated capacitors

Abstract

Amorphous barium titanate (a-BaTiO 3) thin films were deposited by the RF magnetron sputtering technique. The films were grown directly on copper substrates which were maintained at low temperature during deposition (water-cooled substrates). We studied the permittivity (dielectric constant and loss) in the 0.1 Hz–100 kHz range, from − 100 to 225 °C. Leakage currents (DC conductivity) were also studied as a function of the applied field and temperature. At room temperature the dielectric constant is 18.5 (100 kHz), the dissipation factor is 4 × 10 − 3 and the conductivity is 6 × 10 − 16 S/cm (2.7 μm thick films). A dielectric dispersion is observed at low frequencies that becomes pronounced when the temperature is increased.