Amorphous silicon electrostatic microresonators with high quality factors

Phosphorus-doped amorphous-silicon thin-film micromachined mechanical bridge resonators are processed at low temperatures (⩽110 °C) on glass substrates. The microelectromechanical structures are electrostatically actuated, and the resulting deflection is monitored optically. Resonance frequencies in the megahertz range are observed with quality factors up to 5000 when measured in vacuum. The energy dissipation processes in amorphous-silicon thin-film microbridges are discussed. The dominant intrinsic dissipation mechanism is surface loss.