Design of a programmable pressure switch suspended gate MOSFET

A novel programmable pressure switch based on a SG-MOSFET is proposed. The SG-MOSFET structure, in a SOI wafer, is modified by etching the bulk from the back side to build a thin clamped membrane where the MOSFET channel is located in the center. The whole structure forms a diaphragm, in which the bottom plate is a pressure sensitive terminal and the top plate forms the MOSFET gate terminal. The suspended gate is charged by a driver voltage to snap down the gate plate, at the specified pressure, and increase the current across the MOSFET device. An analytical study is presented, in order to provide a design model for the pressure switch device. This device is introduced in the core of a three point oscillator circuit to send a RF signal in on-state and do not send it in off-state.