TCAD Simulation for Nonresonant Terahertz Detector Based on Double-Channel GaN/AlGaN High-Electron-Mobility Transistor

We propose a nonresonant terahertz (THz) detector based on double-channel (DC) GaN/AlGaN high-electron-mobility transistor (HEMT) utilizing a technology computer-aided design platform. The hydrodynamic model is simplified as the drift-diffusion model for nonresonant THz detection simulation. Dependence of THz photoresponse on various structure parameters of the detector is analyzed by simulation. The two typical metrics, responsivity and noise equivalent power (NEP), are theoretically calculated for the optimization of the structure parameters. The optimized responsivity and NEP reach 5.8 kV/W and 50 pW/Hz0.5 at the same gate voltage, respectively, and a minimum NEP of 20 pW/Hz0.5 is obtained. The comparison between our simulation results and the experiment data of single-channel HEMT detector proves that the DC HEMT detector shows an excellent THz detection performance.