Dielectric relaxation and defect analysis of Ta2O5 thin films

The presence of defects in thin-film dielectrics often leads to dielectric relaxation as a function of frequency, in which the dielectric constant dec reases and the loss tangent increases with increasing frequency. Dielectric relaxation results in charge storage capacity reduction under dynamic rand om access memory operating conditions. In this work, the dielectric relaxat ion behaviour of de reactive sputtered Ta2O5 thin film was investigated. Us ing dielectric dispersion measurements as a function of frequency (100 Hz l ess than or equal to f less than or equal to 10 MHz) and temperature (27 de grees C less than or equal to T less than or equal to 150 degrees C), we de termined the dielectric relaxation and defect quantity of the films and pro pose an equivalent circuit on the basis of complex capacitance, admittance and impedance spectral studies.