Channel Material Impact on HEMT Performance: Insights from GaN, AlGaN, and InGaN

Three HEMT designs—Al0.3Ga0.7N/GaN, Al0.3Ga0.7N/Al0.11Ga0.89N, and Al0.3Ga0.7N/In0.11Ga0.89N HEMTs—are numerically examined in this study. The designs vary based on the channel material. The study delves into various aspects such as conduction band profile, electric field distribution, electron concentration, drain and transfer curves along with transconductance profiles, higher order transconductances, figure of merits (VIP2, VIP3, IIP3, IMD3), and breakdown voltage characteristics of these three HEMT designs. The results indicate that InGaN channel-based HEMTs provide superior 2DEG confinement, greater peak electron concentration, higher maximum drain saturation current, and maximum transconductance among the three HEMT configurations. The maximum saturated drain current densities for Al0.3Ga0.7N/Al0.11Ga0.89N HEMT, Al0.3Ga0.7N/GaN HEMT, and Al0.3Ga0.7N/ In0.11Ga0.89N HEMT are 0.34 A/mm, 0.89 A/mm, and 2.27 A/mm. Further, the linearity merits indicate that the InGaN channel HEMT exhibits superior linearity performance. In contrast, the breakdown characteristics show that AlGaN channel HEMT demonstrates a higher breakdown voltage (1501 V) necessary for high-voltage and high-temperature electronics. Consequently, each device is suited for specific applications.