Impact of geometrical parameters on AlGaN/GaN heterostructure MOS-HEMT biosensor

In this work, we present the study of AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistor (MOS-HEMT) biosensors for protein detection. We study the effects of technological parameters including the gate width, gate length, AlGaN layer thickness, oxide thickness layer, and oxide type including HfO₂, Al₂O₃, and SiO₂ on the output characteristics, sensitivity of the MOS-HEMT biosensors, and C–V characteristics. The model developed is compared with experimental data to verify its validity. The AlGaN/GaN bio-MOS-HEMTs show the greatest change in drain current of 208.08 mA with W_g = 100 µm, L_g= 0.3 µm, d_AlGaN=15 nm, and SiO₂ oxide thickness of 25 nm at protein permittivity of 2.5.