The Effect of the Process Parameters on the Electrical Properties of Ni-Cr-Al-Mn-Si Alloy Thin Films

초록

We have fabricated thin resistor films using the DC/RF magnetron sputtering of 75wt%Ni-20wt%Cr-3wt%Al-4wt%Mn-1wt%Si alloy target and studied the effect of the process parameters on the electrical properties for low TCR(Temperature Coefficient of Resistance) films. In sputtering process, pressure and substrate temperature, are varied as controllable parameter. The films are annealed to 400oC in air and nitrogen atmosphere. We have investigated the microstructure using TEM, XRD, EPMA and EDS and measured the electrical properties, the sheet resistance and TCR. The oxygen content and TCR of the films decreased as the sputtering pressure decreased. The oxygen content were 8.9, 8.5 and 1.5wt%, TCR were 105, 85 and 54ppm/ oC for 25, 15 and 5mTorr of the pressure, respectively. The sheet resistance, TCR and crystallinity of the films increases with increasing the substrate and annealing temperature. The sheet resistance and TCR abruptly increased as annealing temperature increased over 300oC in air atmosphere. From TEM and XRD, it is found that these results are due to the existence of NiO on film surface formed by annealing. As a results of them, it is suggested that the sheet resistance and TCR of thin films can be controlled by variation of sputter process parameter and annealing of thin film below 300oC in nitrogen.