Non-Invasive Measurements of the Thickness of YBa2Cu3O7-δ Superconductor Films by Using Dielectric Microwave Resonators

In measuring the surface resistance of thin superconductor films by using the dielectric resonator method, the film thickness should be known if the intrinsic surface resistance (Rs) is to be obtained from the effective surface resistance (R-S(e f f)) because the R-S(e f f) of thin superconductor films strongly S S depends on the film thickness. We demonstrate non-invasive measurements of the superconductor film thickness by using the dielectric resonator method. The method has been very popular for measurements of the R-S(e f f) of superconductor films, for which YBa2Cu3O7-delta films having various S thicknesses are tested. A theoretical relation between the R'ff and the Rs, as previously derived by using the mode matching method, is used for this purpose. The thickness values, as measured at 8.6 GHz by using the dielectric resonator method, appear to be in good agreements with those obtained by using a step profilometer, with the differences being less than 10 %.