The Optimization Of MEMS Piezoresistive Microphone Based On Stress Concentrating Structure

A problem of low sensitivity resulted from a smaller stress across four piezoresistorsand bad signal-to-noise ratio (SNR) exists in traditional MEMS piezoresistivemicrophone all the time, which limits the broad useable range.A MEMS piezoresistive microphone with a new structure is presented in this paper.We use a stress concentrating structure to resolve the problem in the traditional MEMSpiezoresistive microphone. The stress concentrating structure is a U.S. patent and its NO.61/239,068.In this study, a finite element analysis (FEA) is adopted to optimize the parameters ofstructure for XI10technology and ideal condition, respectively. Simulated results showthat stress concentrating strucuture can enhance the stess across the piezoresistor.We may expect the sensitivity to achieve5.18mV/Pa and the signal-to-noise (SNR) toachieve69dB by what we do above. At the same time, we have found the betterparameters of layout for XI10technology and ideal condition, respectively.