Integration and high-frequency characterization of PWB-compatible pure barium titanate films synthesized by modified hydrothermal techniques (< 100°C)

This work reports synthesis of pure Barium Titanate films on Printed Wiring Board at temperatures less than 100°C using hydrothermal synthesis technique. The films thus synthesized were found be crystalline with grain size of 80-100 nm. The film thickness was found to be 300 nm and the capacitance density was in the order of 1 μF/cm², resulting in a dielectric constant of 400. Films grown on thinner Ti foils (<12 microns) showed almost 100% yield. High frequency dielectric properties were obtained from s-parameter measurements using a multi-line calibration approach and were found to be stable up to 8 GHz. Low-cost and low temperature synthesis and stable dielectric properties in the GHz frequencies make them ideal candidates for integral capacitor applications.