Pressure Dependence of Resonant Characteristics of Lateral Comb Drive Resonators in the Free-Molecule Regime

We describe a method for estimating the quality factors of lateral comb drive resonators, especially with trench structures in free-molecule regime, and compare their calculated and experimental values. Although, in past, many studies on air damping of resonators have been carried out, but air damping model for comb drive resonators in the free-molecule regime has not been addressed. We propose mechanism of the energy loss which occurs in the gap between movable plates (known as trench structure), and between a movable plate and a fixed wall. It was shown that the trench structures have almost no effect on the decrease of the quality factor. (C) 2009 The Japan Society of Applied Physics