Enhancement of Sensitivity in AlGaN/GaN HEMT Based Sensor Using Back-Barrier Technique

In the state of the art, most of the Gallium Nitride (GaN) High Electron Mobility Transistor (HEMT) based sensors provide current readout rather than voltage readout. Further, to improve the sensitivity, surface side optimization has been done rather than epi-layer optimization. In this paper, a back-barrier (epi-layer) technique is proposed to improve the sensitivity of the GaN based sensor. To measure the sensitivity, voltage readout is used as it provides better sensitivity than that of a current readout. SILVACO ATLAS Technology Computer Aided Design (TCAD) is used to analyze the performance of the proposed technique. In order to perform a realistic simulation, the TCAD simulation is validated with measured data. The proposed back-barrier technique in the GaN HEMT is shown to improve the sensitivity by 14% as compared to the state of the art. Therefore, the use of the proposed back-barrier technique is considered promising for the GaN HEMT based sensors.