| The mechanical characterization for MEMS directional microphone devices is presented in this thesis.;This microphone diaphragm is intended to be fabricated out of polysilicon through micro-electro-mechanical (MEMS) fabrication technology. The effects of some design parameters have been examined such as the modulus of elasticity, residual stress and mechanical stiffness of the fabricated diaphragms, since they tend to change during the practical fabrication process.;Tow techniques were presented to examine the mechanical properties; bending test and direct nanoindentation, a comparison is made with good agreement. Through out the analysis beam boundary conditions are investigated and corrected to present tested beams real behaviors. Bending technique is also used to investigate the stress in polysilicon layer and to validate the currently used method for mechanical characterization of directional MEMS microphone.;Simulation and comparison analysis, using ANSYS, MATLAB and analytical models shows reliable and easy way to investigate key parameters in fabricated MEMS devices. |
