Practical Techniques for Measuring MEMS Properties

We propose practical analysis techniques to accurately measure geometric, dynamic, and material properties of MEMS. Analytical methods and test structures are presented to extract over a dozen properties by electric probing in a minimal chip area. Geometric properties include fabrication error with respect to layout geometry such as beam widths, gap spacings, etch holes, and beam lengths. Dynamic properties include mass, damping, stiffness, bulk compliance, quality factor, exponential damping factor, displacement amplitude, velocity amplitude, comb drive force, and fringing field factor. Material properties include Young’s modulus, residual stress, shear modulus, Poisson’s ratio, and material density. These techniques differ from those currently available in practicality and that no geometric, dynamic, or material property values are presumed. Only capacitively-based measurements are required.