Deep-level transient spectroscopy was used to investigate the deep-trap levels of radio-frequency sputtered (Sr0.6Ba0.4)TiO3 thin films which had been deposited at various temperatures. Arrhenius plots of the deep-level transient spectra revealed a single trap at 0.45eV in 450C-deposited films. Two traps, at 0.2 and 0.40eV, appeared in 550C-deposited films. Examination of the I-V characteristics of the films, at temperatures ranging from 298 to 403K, revealed the presence of 2 conduction regions. These were an ohmic behavior at voltages below 1V, and a Schottky emission or Poole-Frenkel mechanism above 6V. The barrier height and trapped level were estimated to be 0.46 and 0.51eV, respectively. This corresponded to the trap activation energy of 0.4 to 0.45eV which had been deduced from deep-level transient spectroscopic measurements. The traps which corresponded to activation energies of 0.4 to 0.5eV were suggested to be O vacancies.

Y.P.Wang, T.Y.Tseng: Journal of Applied Physics, 1997, 81[10], 6762-6