Static and dynamic simulation studies on the AlGaN/GaN pressure sensor

In this paper, electro-thermo-mechanical coupled static and dynamic FEM simulations are adopted to study the AlGaN/GaN pressure sensor. The sensor sensitivity is expressed as the drain current change of transistor integrated on the AlGaN/GaN cantilever or circular diaphragm with the applied pressure, namely piezoresistive effect, which is caused essentially by the change of piezoelectric polarization charge. In the static simulation study, how the transistor self-heating, gate metal layer, AlGaN donor-like surface states, and bulk acceptor-like traps in GaN influence the sensitivity are separately illustrated. In the dynamic simulation study, transient behavior of the sensor with the bulk acceptor-like traps and dependences of the natural frequency of circular diaphragm on the self-heating as well as the position of transistor integrated on the diaphragm are analyzed. This work would provide useful guidelines for the design and optimization of AlGaN/GaN pressure sensor.