Measurement of the sheet resistance of resistive films on thin substrates from 120 to 175 GHz using dielectric waveguides

Abstract

A method is reported for the measurement of the sheet resistance, at microwave frequencies, of conducting films supported on thin dielectric substrates. The sheet resistance is found from measurements of the millimeter-wave power transmission through the film using a millimeter-wave source and power meter coupled through dielectric waveguides. The accuracy of this technique does not depend on the precise placement of the waveguide terminations with respect to the substrate, in contrast to methods using metallic waveguides or coils. This method is used to characterize the sheet resistance of semiconductor samples in the frequency range 120–175 GHz and the results are compared to the dc values obtained by conventional techniques. Sheet resistance values can be easily measured by this method in the range from 1 to 1000 Ω.