Characterization of the complex permittivity of thin films using a slow-wave coplanar strips resonator

This paper proposes a characterization method for the electromagnetic properties of thin films, based on the resonance properties of a slow-wave coplanar strips resonator. It is shown that using the resonant frequency and the quality factor of the resonator, permittivity and loss tangent of an unknown thin film at high frequencies such as mm-wave frequencies can be accurately determined. The method is validated by characterizing a silicon dioxide layer in an standard CMOS process as the thin film under test.