Characterization of thin-film low-dielectric constant materials in the microwave range using on-wafer parallel-plate transmission lines

A method is presented to measure the dielectric properties of a thin film over a broad microwave frequency range. The parallel-plate transmission line geometry offers both the advantages of pronounced sensitivity to thin-film properties and exact computation of the value of the dielectric constant and the loss tangent. With multiline thru-reflect-line calibration techniques, the dielectric constant and loss tangent are determined to an accuracy better than 4% at 10 GHz.