TCR control of Ni-Cr resistive film deposited by DC magnetron sputtering

The temperature coefficient of resistance (TCR) is a major and important characteristic of thin film resistors. In this study, we focus on the dependence of TCR on different Ni-Cr film thickness and different annealing conditions. The electron mean free path (MFP) of Ni-Cr film has been determinate. Field Emission Scanning Electron Microscopy (FE-SEM) has been used in studying the morphology of the Ni-Cr film; X-ray diffraction (XRD) has been similarly employed in studying the transformation of the crystallite phase. The TCR performance is stable as the Ni-Cr film thickness is thicker than the electron MFP, and increases slightly as the annealing temperature increases. The 30 nm thickness of Ni-Cr film was annealed at 300 °C; in this phase, metastable amorphous and crystalline film was formed. We obtained the thin film resistors of low TCR under ±5 ppm/°C at −55 and 125 °C.