AlGaN/GaN HEMT on (111) single crystalline diamond

AlGaN/GaN HEMTs have been fabricated directly on (111) oriented single crystal diamond with 1.3 × 1013 cm−2 channel sheet charge density and 731 cm2/Vs mobility. 0.2 µm gate length devices showed 0.73 A/mm maximum drain current density and fT and fmax cutoff frequencies of 21 and 42 GHz.