TCAD Model for TeraFET Detectors Operating in a Large Dynamic Range

Abstract

We present technology computer-aided design (TCAD) models for AlGaAs/InGaAs and AlGaN/GaN and silicon TeraFETs, plasmonic field effect transistors (FETs), for terahertz (THz) detection validated over a wide dynamic range. The modeling results are in good agreement with the experimental data for the AlGaAs/InGaAs heterostructure FETs (HFETs) and, to the low end of the dynamic range, with the analytical theory of the TeraFET detectors. The models incorporate the response saturation effect at high intensities of the THz radiation observed in experiments and reveal the physics of the response saturation associated with different mechanisms for different material systems. These mechanisms include the gate leakage, the velocity saturation and the avalanche effect.

TCAD Modeling for Si–Ge HBT THz Detectors

“…The transient simulation results with and without modulation are in good agreement, and the results with modulation deviate from the quadratic response (proportional to V 2 a ) due to the nonideal voltagecontrolled switches in Figure 3b. This is consistent with the results of the Al-Ga-As-In-Ga-As HFET in [22]. Also, the HB simulation results agree with the transient simulation results without modulation, which validates the HB approach for THz response simulation in Sentaurus.…”

“…This suggests an efficient simulation approach for the Si-Ge HBT response, which is to use HB simulations in the low and intermediate V a ranges and transient simulation without modulation in the high V a range. The results also show the quadratic response at the low and medium intensity range and the response saturation at the high intensity range for the Si-Ge HBT, which is consistent with the V a dependence of the response for the TeraFET detectors [22].…”

“…Using the proposed scheme, we obtain the dynamic range of the THz response for the Si-Ge HBT model and compare the results with the TeraFET TCAD models in [22]. Figure 6 shows the comparison of the THz response and responsivity.…”

“…For the modeling of THz detection, we ran mixed mode simulations in Sentaurus with the TCAD model. We also include the validated TeraFET TCAD models for comparison [21,22]. Figure 3 shows the two schemes of the mixed mode simulations in Sentaurus.…”

“…The time-varying schemes with or without modulation have been validated in [22]. To evaluate the HB scheme, we use the silicon-on-insulator (SOI) MOSFET TeraFET TCAD model in [22]. Figure 4 shows the comparison of the simulated drain response as a function of the THz signal magnitude for the SOI MOSFET model.…”