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

Abstract

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℃. The resistivity shows an abrupt change when the annealing temperature is between 450℃ and 600℃, reaching its peak at 540℃. In contrast, the TCR increases continuously and shifts from negative to positive values at around 510℃. 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℃ 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.