Structural and dielectric properties of spin‐on barium‐strontium titanate thin films

Barium‐strontium‐titanate (Ba0.5Sr0.5)TiO3 thin film capacitors fabricated by a spin‐on technique were studied. At room temperature the films have high dielectric constant e, ranging from 22 to 151 at 1 MHz. Complex impedance spectroscopy was used in order to measure the frequency dependence of their dielectric properties. Cole–Cole reactance versus resistance of experimental data in the frequency range 10 Hz–10 MHz show semicircular behavior indicative of current leakage. The current leakage is proportional to the dielectric constant and in particular the lowest leakage current we measured at 1 MHz was 3×10−5 A/cm2 on samples with e=22.