Electrical properties of N-polar AlGaN/GaN high electron mobility transistors grown on SiC by metalorganic chemical vapor deposition

N-polar high electron mobility transistors (HEMTs) were fabricated from GaN/AlGaN/GaN heterostructures grown on n -type vicinal C-face SiC substrates by metalorganic chemical vapor deposition. The heterostructures had a sheet charge density and mobility of 6.6× 1012 cm-2 and 1370 cm2 V-1 s-1, respectively. HEMTs with a gate length of 0.7 μm had a peak transconductance of 135 mS/mm, a peak drain current of 0.65 A/mm, and a three-terminal breakdown voltage greater than 150 V. At a drain bias of 20 V, the current-gain and power-gain cutoff frequencies with the pad capacitances de-embedded were 17 and 33 GHz, respectively.