Frequency-dependent dielectric constant and loss tangent characterization of thin dielectrics using a rapid solver

The electrical performance of both digital interconnects and embedded RF passives mostly depend on the electrical properties of dielectric materials used in packages and printed circuit boards. The dielectric constant and loss tangent vary as a function of frequency. They need to be accurately extracted in a broad frequency range for successful design of high-performance systems. In this paper, we present a new extraction technique based on the measurement of a rectangular plane pair and curve fitting using a rapid solver. This method is especially applicable to extremely thin dielectric materials that have become available recently. We show the sensitivity of the method to variations in the materials properties, as well as the development of a causal model consistent with Kramers-Kronig relations. This method can be applied to materials with both low and high dielectric constants.