FABRICATION AND DC CHARACTERIZATIONS OF AlGaN/GaN HIGH ELECTRON MOBILITY TRANSISTORS WITH UNDOPED AND DOPED DONOR LAYERS

Two AlGaN/GaN high electron mobility transistors (HEMTs) were fabricated, one of them had an undoped AlGaN donor layer and the second one had an n-doped AlGaN donor layer; and then they were characterized. With 0.15 mu m gate-length and 75 mu m gate-width; the first device exhibited a maximum saturated drain current of 52.5 mA, a threshold voltage of -6 V, a maximum transconductance (g(m)) of 115 mS/mm at -3.7 V gate bias, and a turn-on voltage of 0.4 V. The second one exhibited a maximum saturated drain current of 78 mA, a threshold voltage of -9 V, a maximum transconductance of 150mS/mm at -7 V gate bias, and a turn-on voltage of 1.25 V.