Test structures for dielectric spectroscopy of thin films at microwave frequencies
This work describes the application of two different test structures to execute broadband microwave measurements of the dielectric constant of ceramic thin films. Coplanar waveguide probes and vector network analyzer were used to measure the dielectric constant versus frequency of thin films of lead zirconate titanate and zirconium titanate, fabricated by sol gel methods. One-step lithography was used to produce planar metal-insulator-metal and interdigitated capacitor test patterns. The two test structures are compared for zirconium titanate films. The metal-insulator-metal method has been applied also to a lead zirconate titanate film and to show the capability of computing the dielectric tunability.