Identification of mechanical defects in MEMS using dynamic measurements for application in the production monitoring

In this paper investigations for the non-destructive characterization of MEMS (Micro-Electro-Mechanical- Systems) are presented that can be applied in the production monitoring in early stages. Different aspects and experimental results are shown for silicon membrane structures with artificial faults. The structures were characterized by their resonant frequencies and associated mode shapes measured via laser-Doppler vibrometry. The consequence of the artificial faults is investigated on the basis of the ratios of measured resonant frequencies and the quantified comparison of mode shapes using the MAC-value. The artificial faults have a significant influence on the dynamic properties which depends on their size. According to the results a systematical approach for the dynamic characterization is derived from the results of the investigations for a possible application in the production monitoring.