Non-destructive measurements of dielectric constant of thin dielectric films with metallic backing using coplanar transmission line

This paper introduces a new characterization method of measurement for the permittivity of dielectric material in thin films deposited on metallic/semiconductor substrate. The method uses the conformal mapping technique to extract the relative permittivity and loss tangent is a non-destructive way. After measuring the S-parameters of the material when placed on a coplanar transmission line, an inverse problem is applied to extract the dielectric constant. The permittivity measurement is done for thin film of 5 micrometer thickness. The obtained results are satisfying and encouraging and the method is validated using standard FEM simulation software.