Fast Impedance Spectroscopy Method for Insulating Layers with Very High Impedance

This paper presents the fast impedance spectroscopy method for objects with a very high impedance |Zx| ≥ 1GΩ modeled by RC networks. The method is suitable for predicting the lifetime and reliability of insulating materials. The fast impedance spectroscopy method was tested on insulating layers which were part of the system metalinsulator-metal (MIM). The method is based on measurements of the power loss and phase shift in the AC voltage divider, which consists of the measured system MIM and of the known impedance. Computer controlled instruments measure the gain and phase shift between the two outputs of alternating electrical circuit and a computer program calculates the parameters of the impedance spectroscopy from these values. The output is the graphical and tabular impedance characteristics of the MIM system, namely: the dielectric loss of the insulating film, imaginary part of impedance, loss factor, parallel resistance Rp and the capacity Cp of the MIM system, all frequency dependent. Frequency characteristics provide an analysis of loss mechanisms that may affect the quality and reliability of the insulating layers.