Terahertz Antenna-Coupled Wire-Channel Field-Effect Transistors Based on AlGaN/GaN Heterostructures

We propose a terahertz (THz) antenna-coupled wire-channel field-effect transistor—modified EdgeFET (m-EdgeFET), formed by combining single-gate FinFET and dual-side-gate EdgeFET concepts, which is used for THz detection. The proposed hybrid design was implemented on AlGaN/GaN high-electron-mobility transistor (HEMT) structures, demonstrating distinct response characteristics under 150 GHz and 300 GHz radiation at room temperature. The responsivity dependence on the channel length was determined, revealing that the peak responsivity reached up to 6.5 V/W at a gate voltage of −3 V, i.e., at a gate bias that is an order lower in magnitude than that required for EdgeFET to reach the maximum response. Meanwhile, the gate leakage current decreased by an order of magnitude (to about 1 nA) compared to a FinFET with similar geometry. The proposed geometry was shown to operate in two regimes: source-drain coupling (SD) and gate coupling (GG) of THz radiation with the transistor wire channel. The results confirm that the m-EdgeFET design is suitable for electrically controlled and fast THz detection.