The influence of material structure of thick film resistor on C-V characteristic

The materials for thick film resistive layers are inhomogeneous mixtures. The layers contain particles of conductive functional component (in this case, carbonic) dissipated in an insulative matrix. The current-voltage characteristics of resistors prepared by thick film technology are nonlinear. The deviation from linearity of the C-V characteristic may have contributions from both the resistive layer material and the contact-resistive layer interface. The object of this work was the investigation of the influence of these two systems, the resistive layer and the resistive layer/contact interface, with regard to their influence on the nonlinearity. Measurement of third harmonic voltage was used for determination of nonlinearity of the C-V characteristic, as direct measurement of the C-V characteristic does not enable discovery of the small linearity deviation of the C-V characteristic. The samples were powered by a pure sinusoidal signal. The pure sinusoidal signal was distorted by transit through layer and interface inhomogeneity. For investigation, sample resistors with different size (width and length) were used. The third harmonics measurement was performed on samples powered by a signal with constant current density and constant current.