ELECTRICAL-PROPERTIES OF AMORPHOUS BARIUM-TITANATE FILMS PREPARED BY LOW-POWER RF-SPUTTERING

Abstract

In this study r.f. magnetron sputtering is employed to deposit amorphous Ca-doped titanate film on silicon substrate. The as-deposited BaTiO3 film has a 1 MHz dielectric constant of 14 and a refractive index of 1.9 at a wavelength of 6328 angstrom. The capacitance voltage characteristics of the BaTiO3 film suggest a Poole Frenkel transport mechanism with oxygen vacancies as one of the positively charged traps. The remanent polarization in the BaTiO3 films affects its current voltage curve. The fatigue behaviour of the BaTiO3 films is improved by the introduction of oxygen gas during sputtering and/or the addition of dopant calcium. No fatigue is observed for (Ba0.9Ca0.1)TiO3 film up to a switching cycle of 10(10).