AlGaN/GaN High Electron Mobility Transistor (HEMT)-Based Dual-Metal Gate Architecture for Biosensing Applications

The electrical characteristics and sensitivity of AlGaN/GaN metal-oxide-semiconductor high electron mobility transistor (MOSHEMTs) with dual metal single gate (DMSG) architecture are investigated and compared via Sentaurus technology computer aided design (TCAD) simulations with conventional single metal single gate (SMSG) devices. This technique reduces gate leakage and current collapse by using aluminium oxide as a high-k dielectric. Simulation results clearly reveal that DMSG devices exhibit superior performance with high drain current, high transconductance, and improved sensitivity compared to their SMSG counterpart. Moreover, precise sensing of biomolecules including zein, choline oxidase (ChOx), biotein, glucose, and urease has been investigated by adopting the DMSG structure. The band gap is ontinuity and peak electric field significantly improves the channel’s carrier confinement, leading to high sensitivity and making it feasible for the future biosensing applications.