Enhancement of micromechanical resonator manufacturing precision via mechanically-coupled arraying

Abstract

A statistical comparison between the resonance frequency variations of stand-alone micromechanical disk resonators and mechanically-coupled array composites of them reveals that mechanically-coupled arraying of on-chip micromechanical resonators can very effectively enhance the manufacturing repeatability of resonance frequencies. In particular, twenty 3-disk resonator array-composites on a single die achieve a measured resonance frequency standard deviation as small as 165.7 ppm around a 61.25 MHz average, which is significantly smaller than the 316.4 ppm measured for twenty stand-alone disk resonators on the same die. This new standard deviation reduces the expected filter percent bandwidth achievable with a 90% confidence interval without the need for trimming from the 1.89% of previous work to now just 0.86%. Larger arrays should further reduce the frequency standard deviation, perhaps to the point of allowing trim-free RF channel-select bandwidths with reasonable manufacturing confidence interval.