Complex Permittivity Measurements of Thin Ferroelectric Films Employing Split Post Dielectric Resonator

Abstract

Split post dielectric resonator (SPDR) operating at frequency about 19 GHz has been used for measurements of permittivity and dielectric loss tangent of ferroelectric films deposited on low loss dielectric substrates. These properties are evaluated form measured resonant frequencies and Q-factors of SPDR with substrate (with and without deposited film) employing full wave electromagnetic theory. Sensitivity and uncertainty analysis have shown that it is possible to measure real permittivity of ferroelectric films having thickness in the range 200 nm to 2000 nm and permittivity range 100–10000 with uncertainties similar to uncertainties of their thickness. Loss tangent resolution for this technique is about 1 × 10−4 for samples having permittivity about 1000 and thickness of the order of 500 nm.