Frequency trimming and Q-factor enhancement of micromechanical resonators via localized filament annealing

A batch-compatible, post-fabrication annealing technique based upon filament-like heating of microstructures is demonstrated as an effective means for trimming the resonance frequencies (f/sub 0/'s) and increasing the quality factors (Q's) of surface-micromachined, polysilicon, mechanical resonators. Although the technique is straightforward, involving the mere application of a suitable voltage between the anchors of a micromechanical resonator, it provides a substantial range of adjustment, with frequency trims of over 2.7% and Q increases of up to 600%, depending upon resonator fabrication history. By pulsing the anneal voltage waveforms, controlled frequency trims of less than 16 ppm per trial are achievable.