Recessed-Gate Enhancement-Mode AlGaN/GaN Heterostructure Field-Effect Transistors on Si with Record DC Performance

Enhancement-mode devices are in the centre of current research on group-III nitride transistors. The realisation of high-performance enhancement-mode transistors via gate recessing requires damage-free processing. We report on enhancement-mode AlGaN/GaN-on-Si heterostructure field-effect transistors (HFETs) fabricated with a damage-free digital etch technique. The threshold voltage (V-th) achieved is as high as +0.5V. For AlGaN/GaN-on-Si HFETs, a record extrinsic transconductance (g(m)) of 420mS/mm and a record maximum drain current I-d,I-max of 500mA/mm have been demonstrated. Furthermore, proper turn-off characteristics have been realised. Pulsed I-V characteristics reveal nearly no current collapse. (C) 2011 The Japan Society of Applied Physics