Demonstration of p-GaN/AlGaN/GaN High Electron Mobility Transistors With an Indium–Tin–Oxide Gate Electrode

In this study, p-GaN/AlGaN/GaN high electron mobility transistors (HEMTs) with indium-tin-oxide (ITO) gate electrodes are demonstrated. The DC measurements for the devices show a drain current (ID) of 438 mA/mm at a VDand a VGof 10 and 8 V, respectively. A maximum gm of 92.1 mS/mm and a specific ON-resistance (Ron· A) of 1.86 mΩcm2are obtained. Furthermore, the robustness of the ITO gate electrode atop the p-GaN layer under the forward gate bias is studied, indicating stable IG- VGand ID- VGcharacteristics for a gate voltage of less than 11 V, which is higher than the compared device with Ni/Au Schottky gate contact. Therefore, ITO gate electrodes, which are compatible with the Light-emitting diode (LED) process, are a promising alternative for p-GaN HEMT technologies.