A Modified Method to Model the Effect of Residual Stress on Touch-point Pressure and Pull-in Voltage for MEMS Capacitive Transducers using Square Diaphragm

The silicon-based materials used for fabricating the square diaphragm for Micro-electro-mechanical systems capacitive transducer have inherent stress. This stress is known as residual stress. The presence of stress influences the mechanical behavior of the material, thereby influencing the performance characteristics of the devices. A methodology discussed earlier for modeling the small deflection of square diaphragm has been extended to take into account the effect of residual stress on the pull-in voltage and touch-point pressure. The results are compared with simulated and experimental ones.