Gate-Recessed Enhancement-Mode InAlN/AlN/GaN HEMTs With 1.9-A/mm Drain Current Density and 800-mS/mm Transconductance

Having a drain current density of 1.9 A/mm, a peak extrinsic transconductance of 800 mS/mm (the highest reported in III-nitride transistors), ft/f_max of 70/105 GHz, and V_br of 29 V, 150-nm-gate enhancement-mode InAlN/AlN/GaN high-electron-mobility transistors are demonstrated on SiC substrates using plasma-based gate-recess etch. The possible plasma-induced damage in the gate region was investigated using interface-trap states extracted from temperature-dependent subthreshold slopes.