Piezoresistive properties and structure of hydrogen-free DLC films deposited by DC and pulsed-DC unbalanced magnetron sputtering

In the present research hydrogen-free DLC films were deposited by unbalanced DC and pulsed DC magnetron sputtering. Gauge factor, electrical properties and structure of the films were investigated versus technological conditions looking at the correlations between the gauge factor and other parameters relating to DLC films. Effects of the sputtering pulse frequency and substrate temperature were studied. The dependence of the gauge factor of DLC films on structure (parameters of the Raman scattering spectra) and resistivity was found to be in good accordance with a percolating metal and insulator composite model.