Structural and electrical properties of rfhyphen;sputtered amorphous barium titanate thin films

摘要

Structural and electrical properties of rfhyphen;sputtered amorphous BaTiO3thin films grown on waterhyphen;cooled substrates have been investigated. The dielectric and electrical properties have been studied for films grown under varying sputtering gas composition (Ar+O2gas mixtures) as a function of film thickness, frequency, and temperature. Ashyphen;grown films were amorphous in nature and highly transparent. Posthyphen;deposition annealing had no discernible effect either on film structure or dielectric properties, and there was no evidence of ferroelectricity. Films sputtered in pure argon showed a dielectric constant egr;rsquo;sim;12 with little dependence on frequency (0.1ndash;100 kHz) over the temperature range 0ndash;75thinsp;deg;C. The dielectric properties were a function of film thickness and the percentage of oxygen in the sputtering gas during growth. The thicknesshyphen;dependent dielectric properties of amorphous BaTiO3thin films on conducting glass substrates could be satisfactorily explained by a model based on the existence of electrode barriers. The high breakdown voltage (106V/cm), charge storage capacity (3.1 mgr;C/cm2), and frequencyhyphen; and temperaturehyphen;dependent dielectric properties ofahyphen;BaTiO3films sputtered in pure argon show promise for application as insulating layers in thinhyphen;film electroluminescent display devices.