Laser trimming of CuAlMo thin-film resistors: effect of laser processing parameters

This paper studies the effect of varying laser trimming parameters on the electrical performance of CuAlMo thin film resistors. The films were prepared on Al2O3 substrates by DC magnetron sputtering, before being laser timed to target resistance value. The effect of varying laser power, Q-rate and bite size on the resistor stability and tolerance accuracy were then systematically investigated. By reducing laser power and bite size and balancing this with Q-rate setting, it was possible to achieve resistor tolerance accuracies of <±0.5% with significant improvements in resistor stability.