The Effect of Surface Roughness on the Temperature Coefficient of Si-Cr-O Thin Film Resistance

Thin film resistors are widely used in hybrid analog integrated circuits. The low Temperature Coefficient of Resistance (TCR) is an important feature of thin film resistors, maintaining stable circuit performance. Here, we systematically study the dependence of TCR in Si-Cr-O film resistor on surface roughness. The Si-Cr-O thin-film resistors and substrates with different roughness were fabricated by magnetron sputtering. Furthermore, Scanning Electron Microscopy (SEM) and Atomic Force Microscope (AFM) were used to characterize the morphology of the film. More importantly, it was found the property of TCR would elevate with surface roughness increasing and thickness of resistor decreasing. This finding provides experimental groundwork for reducing TCR of thin film resistance and supply guidelines for understanding the physical nature of thin film resistance in advanced ICs technology.