Investigation of Quaternary Barrier InAlGaN/GaN/AlGaN Double-Heterojunction High-Electron-Mobility Transistors (HEMTs) for High-Speed and High-Power Applications

We report direct current (DC) and microwave performance of a 50-nm gate length (Lg) quaternary-based InAlGaN/GaN/AlGaN high-electron-mobility transistor (HEMT) on SiC substrate with SiN passivation and by using a T-gate. The proposed HEMT structure is simulated using industry-standard Synopsys Sentaurus technology computer-aided design (TCAD). The regrown n++ GaN source/drain ohmic contacts show a peak drain current density (Idmax) of 2.9 A/mm along with low on-resistance of 0.49 Ω mm. A record power gain cut-off frequency (fmax) of 425 GHz along with current gain cut-off frequency (ft) of 310 GHz are obtained by the substantial reduction in the device's intrinsic and extrinsic parasitic resistances and capacitances. A very thin 7-nm In0.13Al0.83Ga0.04N quaternary barrier with an AlGaN back-barrier structure effectively mitigates the short-channel effect with an improved breakdown voltage (VBR) of 38 V. The prominent DC and microwave characteristics of the proposed HEMT make it an appropriate candidate for next-generation high-power millimeter-wave electronics.