Theoretical potential of extremely high quality factors of β-Ga₂O₃ based MEMS resonators

Abstract

We show theoretically and via simulation that β-Ga2O3 semiconductor is potentially a superior material for mechanical resonating structures applicable to micro-electro-mechanical system sensors. In particular, β-Ga2O3 may enable a thermoelastic dissipation loss limited quality factor on order of 108, which is the highest among all known conductive materials including metals and semiconductors. The Akhiezer limit of the quality factor and frequency product of resonators based on β-Ga2O3 is predicted to be extremely high at 3.3 × 1015 Hz. β-Ga2O3 based resonators may even exhibit higher quality factors than those based on ultra-low expansion glass due to the elimination of metal electrodes in the former. We also present a method to graphically extract the quality factor from the frequency response function without measuring the FWHM bandwidth.