Characterization of lutetium oxide-based thin-film capacitors by impedance spectroscopy

The impedance spectroscopy method has been applied for diagnostics of lutetium oxide-based MIM (metal–insulator–metal) thin-film structures with a different insulator thickness, from 0.2 μm to 0.55 μm. For frequencies 10 μHz–10 MHz and temperatures 300 K–500 K, the total impedance response of examined specimens comes from: Lu2O3 film, near-electrode regions and resistance of electrodes and leads. The equivalent electrical circuit models containing the following elements: series resistance of electrodes and leads; resistance, capacitance and constant phase element, which characterize the volume of the film; and resistance and constant phase element, which characterize near-electrode regions, have been proposed to describe the dielectric response of Al/Lu2O3/Al thin-film capacitors. The values of characteristic parameters of these elements have been determined and discussed.