On-wafer stiffness and displacement measurements of freestanding MEMS structures

An original experimental method is presented for measuring the stiffness and displacement characteristics of small size freestanding mechanical elements on actual MEMS devices. This setup allows, using analytic and finite-element method mechanical calculations, the extraction of the elastic modulus of the materials used in such mechanical elements, thus eliminating the need of special integrated test structures. The setup has, respectively, a force and displacement measurement accuracy better than 1 μN and 50 nm. Its application is demonstrated by the characterization of a MEMS magnetostatic switch.