Simulation and measurement of pressure dependent Q-factors in NEMS resonators

The fluidic damping and the hereof resulting Q-factor of various mechanical resonators with gaps of nanometer size between suspended part and substrate was theoretically and experimentally determined. These investigations have been carried out in the pressure regime from atmospheric pressure down to about 3 Pa. The air flow in the nanogap between the movable part of the device and the substrate was modeled by extending the mixed level model presented in [1, 2] to the slip flow and molecular dynamical regime. The pressure-dependent measurements were carried out using a Laser-Doppler vibrometer. The extracted Q factors conform very well with those expected from theory in every pressure regime. This is a noticeable result, because even at normal pressure the range of validity for a continuum-theoretical description is reached for the nanometer feature sizes considered in this work.