Investigation of thermo-elastic damping of vibrations of rectangular and ring-shaped mems resonators

The paper deals with finite element analysis of damped modal vibrations Q-factor values determined by taking into account the thermally-elastic damping. Modal properties of square- and ring-shaped MEMS resonators have been investigated by taking into account the layered structure of MEMS and the influence of the geometry of the clamping zone. The calculations have been performed by employing the COMSOL Multiphysics finite element software. The solution method has been verified comparing numerically and analitically obtained damped modal properties of cantilever MEMS resonator. Experimental investigations of Q-factor values have been performed. The comparison of calculated and experimentally obtained resonant frequencies and Q-factor values indicated good agreement of tendencies of change of the quantities against temperatur

Finite element analysis of thermo-elastical modal damping of mems vibrations

The paper deals with finite element analysis of damped modal vibrations Q-factor values determined by thermal-elastic damping in micro-electrical-mechanical systems (MEMS). Mathematically the problem is formulated as a complex eigenvalue problem. Verification problems have been solved by using several computational environments and different presentations of model equations in order to comprehend and reduce the influence of rounding errors. The analysis of damped modal properties of selected real MEMS resonator revealed the main features of thermal-elastic damping by taking into account 3D geometry of the resonator and anchoring (clamping) structur

Influence of 0-level packaging on the microwave performance of RF-MEMS devices

RF-MEMS devices (Radio Frequency-MicroElectroMechanical Systems) are made of moveable and fragile structures (membranes, beams, cantilevers,…) that must be encapsulated for protection and for stable performance characteristics. Zero-level or wafer-level packaging developed so far has been limited to dc-components. This paper elaborates on the design and fabrication of a 0-level package for housing RF-MEMS devices. The fabrication process is described and packages are characterized in terms of mechanical strength, hermeticity and microwave performance in the range 1-50 GHz. Simulations and experiments show minimal impact of the package on the RF losses if the cap has a minimal height of 50 µm, if low-loss materials (e.g., glass) are used, and if matched RF feedthroughs are implemented. Finally, in a multi-switch design, we recommend to minimize the number of feedthroughs, i.e. to use a single cap for the entire design

Influence of 0-level packaging on the microwave performance of RF-MEMS devices

RF-MEMS devices (Radio Frequency-MicroElectroMechanical Systems) are made of moveable and fragile structures (membranes, beams, cantilevers,…) that must be encapsulated for protection and for stable performance characteristics. Zero-level or wafer-level packaging developed so far has been limited to dc-components. This paper elaborates on the design and fabrication of a 0-level package for housing RF-MEMS devices. The fabrication process is described and packages are characterized in terms of mechanical strength, hermeticity and microwave performance in the range 1-50 GHz. Simulations and experiments show minimal impact of the package on the RF losses if the cap has a minimal height of 50 µm, if low-loss materials (e.g., glass) are used, and if matched RF feedthroughs are implemented. Finally, in a multi-switch design, we recommend to minimize the number of feedthroughs, i.e. to use a single cap for the entire design

Poly-SiGe-based MEMS Xylophone Bar Magnetometer

peer reviewedThis paper presents the design, fabrication and preliminary characterization of highly sensitive MEMS-based Xylophone Bar Magnetometers (XBMs) realized in imec’s poly-SiGe MEMS technology. Key for our Lorentz force driven capacitively sensed resonant sensor are the combination of reasonably high Q-factor and conductivity of imec’s poly-SiGe, our optimized multiphysics sensor design targeting the maximization of the Q-factor in a wide temperature range as well as our proprietary monolithic above-CMOS integration and packaging schemes. Prototypes 3-axis devices were fabricated and characterized. We present optical vibrometer and electrical S-parameter measurements of XBMs performed in vacuum with a reference magnet at increasing sensor separation. The optical oscillation amplitude is well correlated with the magnetic field amplitude. The electrical 2-port measurements, 1st port as Lorentz force actuator and 2nd port as capacitive sensor, also reproduces the designed magnetic field dependence. This opens the way towards the on-chip integration of small footprint extremely sensitive magnetometers