A novel pressure sensor based on a Suspended Gate MOSFET is presented. The SG-MOSFET structure, fabricated in a
SOI wafer, is modified by etching the bulk of the wafer back side in order to create a thin clamped membrane and to be
able to measure pressure displacements. 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 where the air-gap is proportional to the pressure
application as gate insulator. The change of this air-gap distance modifies the drain current of the sensing MOSFET.
The gate is suspended by arms allowing to modify the sensitivity of this sensor by a drive voltage. Two operation modes
are proposed, one uses the drain current variations as output signal and the second one take advantage of the snap
down effect. A model along with Finite Element Method simulations were made to provide a design model for the
pressure sensor. Some pressure sensors were been fabricated with different dimensions.