Identification of geometrical parameters of MEMS from measured resonant frequencies

In this paper a new method is presented to identify geometrical parameters of MEMS non-destructively. The used identification methodology is based on a combination of dynamic measurements using a Laser Doppler Vibrometer and finite element analyses. This method can be applied to inspect MEMS manufacturing processes in early stages e.g. on wafer level. First investigations of 25 test structures of silicon pressure sensors were done and the identification of one parameter the thickness of membrane was performed. Cross sections were analysed in a scanning electron microscope to validate the identification results.