The effect of microstructures on the electrical properties of Cr–Si–C thin film resistors

The resistivity and temperature coefficient of the resistance (TCR) of Cr–Si–C films are investigated with various microstructures changed by annealing up to 1000 °C. The resistivity shows an abrupt change when the annealing temperature is between 450 °C and 600 °C, reaching its peak at 540 °C. In contrast, the TCR increases continuously and shifts from negative to positive values at around 510 °C. The crystal phase, microstructure and composition of the Cr–Si–C films are analyzed using X-ray diffraction, scanning transmission electron microscopy, and energy dispersive X-ray spectroscopy, respectively. The abrupt change in resistivity and TCR values above 450 °C annealing are attributed to the growth of Cr silicide crystals inside the amorphous Cr–Si–C film. The relationship between electrical properties and microstructures of Cr–Si–C film is discussed with the electrical current path model based on physical analysis.