A new job for the pseudo-MOS transistor: working in the pressure sensors field

Recently, pressure sensors that combine SOI structures with the properties of piezoelectric layers have been developed. With a SOI-MOSFET used as a transducer element, the sensor can detect pressures just over a threshold value, corresponding to the inversion onset. In this paper, a pseudo-MOS/SOI transistor is the transducer that enhances the work regime: accumulation or inversion for a SOI-MOSFET like regime and depletion for a J-FET like regime. A PZT layer is used for sensing the pressure. New analytical models for the sensor sensitivity in various regimes are presented. ATLAS simulations, based on the concept of "equivalent gate voltage", verify how does the sensor works and provide the current through the transducer. A strongly non-linear characteristic of the sensor results.