Broadband characterization of high-dielectric constant films for power-ground decoupling

We evaluated the broadband dielectric permittivity and impedance characteristics of high dielectric constant films for decoupling capacitance applications at frequencies of 100 to 10 GHz. In order to extend the measurements to the microwave range, we developed an appropriate expression for the input admittance of a thin-film capacitance terminating a coaxial line. The theoretical model treats the capacitance as a distributed network and correlates the network scattering parameter with complex permittivity of the specimen. The method eliminates the systematic uncertainties of the lumped element approximations and is suitable for high-frequency characterization of low-impedance substrates.