This paper deals with the design optimization of new high sensitivity microphones in SOI technology for gas sensing applications. A novel geometry of bossed silicon membranes used as mechanical transducer has been studied by Finite Element Modelling. Device fabrication is achieved from SOI substrates through deep backside anisotropic etching and shallow front side RIE to define a bossed sensing membrane with two reinforced areas. Thus, the influence of thin film stresses on the device performance is largely decreased. Polysilicon gauges are located on the reinforced areas to get a better linearity in pressure
