Electrical Properties of CrSi Thin Film Resistors for High Precision Analog Circuits

CrSi thin films are deposited on SiO2 by reactive magnetron sputtering in a mixed atmosphere of argon and nitrogen, where nitrogen is the reactive gas, following by annealing in nitrogen and hydrogen at different temperatures. The effects of sputtering atmosphere (nitrogen flow rate) and annealing temperature on film structural and electrical properties of these films are investigated. It’s found that nitrogen doping inhibits grains growth to a certain extent and the effects of nitrogen doping amount on the square resistance of annealed films are different. TCR (temperature coefficient of resistance), by adjusting the sputtering atmosphere and annealing temperature, can be effectively controlled within the original 10% range, that is, optimized from about ±20 ppm/ ℃ to ±2 ppm/ ℃, indicating that resistors possess more excellent stability performance. This work probes the impact trend of key process parameters on square resistance and TCR in detail, which have important reference value for the development of high-precision resistors technology.