High-Uniformity and High Drain Current Density Enhancement-Mode AlGaN/GaN Gates-Seperating Groove HFET

In this paper, we report on a novel E-mode AlGaN/GaN gates-seperating groove heterostructure field-effect transistor (GSG HFET). The current turn-on/off is controlled by changing gate voltage to regulate the horizontal energy band between the double gates. A threshold voltage of 0.23 V and a high drain current density of 851 mA/mm are obtained in GSG HFET. Compared with the proposed depletion-mode device, the maximum drain current of the GSG HFET deceases slightly (about 7%). It is noteworthy that the threshold voltage is less sensitive to the etching time. The devices show high-uniformity threshold voltage of 0.23 V within wide etching time range from 5 to 9 min.