AlGaN/GaN High Electron Mobility Transistor based Pressure Sensor for Harsh Environments

We present a novel pressure sensor dedicated for high pressure measurement in harsh environments. For this purpose, we use III-V materials alloy (GaN and AlGaN in our case) that have semiconductor, piezoelectric and pyroelectric properties and enable the design of advanced devices suitable for a harsh environment. A multilayer diaphragm containing AlGaN/GaN/AlN heterostructure, which creates a High Electron Mobility Transistor (HEMT) as a stress-sensitive gauge, acts as a mechanical sensing device suited to environments with high temperature (>600°C), high pressure (>10atm) and corrosive atmosphere. In addition to the previous work that demonstrated the feasibility and modeling of this type of sensor and their preliminary characterization, we present here the sensor structure along with its pressure sensitivity obtained from a test bench using a calibrated piezoelectric actuator.