Simulating the real geometry of an electrostatic switch to study the effect of uncertainties on the pull-in voltage

摘要

Modelling of MEMS is one of the difficulties faced in advancing the design. The parameters fed to the simulator consist of the material properties and the geometry of the structure. Material wise, researchers are working on developing precise characterisation techniques to ameliorate the mechanical definition of structural material used. More work is now ongoing to ameliorate the fabrication process in order to get precisely what we designed. Concerning the electrostatic actuated RF MEMS switches, we always found a big offset in the pull-in voltage between what we design and what we measure. For that reason, we launched a study on the parameters affecting the actuation voltage in order to understand which is the most penalizing in order to ameliorate the process in this direction. The reverse engineering method will permit us to understand and specify the parameters affecting most the offset between simulated and fabricated switches. A study was done in this direction in order to define the critical parameters and predict the shift in the results.