Damping mechanisms in light and heavy-doped dual-ring and double-ended tuning fork resonators (DETF)

We present models and measurements of lightly-doped and heavily-doped dual ring/dual-bar and double-ended tuning fork (DETF) resonators. Both models and measurements indicate that the Q of these resonators is only slightly impacted by the doping level, despite being dominated by thermoelastic dissipation (TED), which has a strong dependence on doping-dependent material properties. We compare experimental measurements of Q over a range of temperatures with models for TED, anchor damping and squeeze film damping. We found that the Q of light and heavily-doped resonators can be accounted for by a combination of TED and anchor or squeeze film damping. These results indicate that it is possible to fully account for the damping mechanisms in MEMS resonators if temperature-dependent measurements of Q are compared with models of the important mechanisms including the temperature-dependent materials properties.