Capacitive Micromechanical Resonators And Filters

As the demands of high performance and miniaturization of electronic system, devices are developing to be with higher performance, lower power and smaller, of which high Q resonators and filters will be crucial for system on chip in the future. RF(radio frequency) MEMS resonators and filters, with their low power consumption, small size, potential to be integrated with IC and high frequency selectivity, will be crucial in the next generation communication systems.This thesis focuses on design and manufacture of capacitive micromechanical beam resonators and filters. Mechanical equivalent circuit is used for the analysis of the microelectromechanical resonators and filters. FEA and EDA software are employed to design the resonators and filters. The effect of the design and parasitic parameters were evaluated. Several devices, such as clamped-clamped beam resonators, free-free beam resonators and clamped-clamped beam filters, are fabricated by polycrystalline silicon surface micromachining technology. Polysilicon corrosion and interconnection protection during the release are discussed with solutions presented.Chip level test is carried out on a customized probe station, devices were measured in atmosphere, whose characteristics are corresponded well to the design and simulation. A vacuum test platform has also been set up. Finally, future research directions of micromechanical resonators and filters are discussed.