Parameter Identification on Wafer Level of Membrane Structures

A fast identification method of membrane structure parameters is investigated for an early stage of the manufacturing process. The approach consists of performing optical measurement of the modal responses of the membrane structures. This information is used in an inverse identification algorithm based on a FE model. Device characteristics can be determined by measured modal frequencies which are fed into a model based on the FE simulations. The number of parameters to be identified is thereby generally limited only by the number of measurable modal frequencies. A quantitative evaluation of the identification results permits furthermore the detection of defects like cracks which cannot be classified within a FE model. The approach is validated by first measurements which have shown a good correlation between simulated and measured modal frequencies.