490 mA/mm drain current and 1.9 V threshold voltage enhancement-mode p-GaN HEMTs and high-temperature characteristics

In this paper, enhancement-mode AlGaN/GaN p-type GaN cap layer high electron mobility transistors (p-GaN HEMTs) with Ti/Au gate metal are fabricated and electrically characterized. The post gate annealing (PGA) treatment at 300 degrees C for 10 min is utilized to improve the devices' characteristics. As a result, the p-GaN HEMTs achieve a high drain current (IDS) of 490 mA/mm at VGS = 7 V with a high threshold voltage (VTH) of 1.9 V. Meanwhile, the pulse measurements show good dynamic characteristics, and the temperature-dependent characteristics indicate that the VTH has excellent high-temperature stability from 25 degrees C to 175 degrees C. Besides, it can be found that the temperature will affect the capacitance-voltage (C-V) and transconductance curves, which is related to the hole energy and electron mobility at different temperatures.