On-state performance enhancement of AlGaN/GaN Fin-HEMTs by using arcuate sidewalls

In this study, AlGaN/GaN Fin-HEMTs with different nanochannel geometric parameters were fabricated and comprehensively characterized. In the arcuate Fin-HEMTs, where the sidewalls arcuate from the source to the drain side, enhancements in the drain current density and transconductance were observed. By extracting and analyzing parameters obtained from small-signal measurements and conducting an analysis of gate capacitance, it was demonstrated that the enhancement can be attributed to the modulation of gate capacitance. This enhances the control capability of the gate over channel carriers, resulting in increased transconductance of the device. Due to the enhanced transconductance, the fT and fmax of the arcuate Fin-HEMTs are both enhanced. Notably, the arcuate Fin-HEMTs achieved a power-added efficiency of 71.4% at a frequency of 3.6 GHz and a drain voltage of 20 V. Meanwhile, the linearity of the arcuate Fin-HEMTs is improved compared with the conventional Fin-HEMTs.