Characterization of Thin Metal Films Using Terahertz Spectroscopy

A theoretical model is presented to simulate the transmission of thin metal films. Using terahertz spectroscopy, the two key characteristic parameters, conductivity and thickness, are determined simultaneously by fitting the experimental data to the theoretical model. Three different metal films, aluminum, copper, and silver, are investigated. The measured conductivities are significantly less than the bulk values. The sample thicknesses obtained are consistent with those estimated by the quartz thickness monitor.