Investigation of T-Gate AlGaN/AlN/GaN HEMT for Biosensing Application and Sensitivity Optimization

This study delves into the use of AlGaN/GaN-HEMTs with biomolecule cavities positioned on either side of the gate, extending towards the drain and source, to evaluate their effectiveness and sensitivity as biosensors. We simulate the presence of neutral and charged biomolecules by adjusting the properties of the cavities. To gauge the performance of these devices, we measure the threshold voltage sensitivity (SVth) and drain current sensitivity (SIDS). Our findings indicate that these devices exhibit sensitivity increases of up to 32% in threshold voltage and 92% in drain current due to the presence of biomolecules. Additionally, how the thickness of the AlGaN barrier and the aluminum mole fraction affect these sensitivities was investigated. The simulations suggest that devices with thinner barrier layers and lower aluminum content are more responsive to changes in the dielectric properties of biomolecules on the surface during T-gate operation. This research highlights the key factors for optimizing AlGaN/GaN-HEMTs as highly sensitive biosensors.