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

Abstract

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 ( $\text{I}_{\mathrm{ D}}$ ) of 438 mA/mm at a $\text{V}_{\mathrm{ D}}$ and a $\text{V}_{\mathrm{ G}}$ of 10 and 8 V, respectively. A maximum ${g} _{\mathrm{ m}}$ of 92.1 mS/mm and a specific ON-resistance ( $\text{R}_{\mathrm{ on}}\cdot {\mathrm{ A}}$ ) of 1.86 $\text{m}\Omega $ cm2 are obtained. Furthermore, the robustness of the ITO gate electrode atop the p-GaN layer under the forward gate bias is studied, indicating stable $\text{I}_{\mathrm{ G}}-{\mathrm{ V}}_{\mathrm{ G}}$ and $\text{I}_{\mathrm{ D}}-{\mathrm{ V}}_{\mathrm{ G}}$ characteristics 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.

Keywords

• GaN
• high electron mobility transistor (HEMT)
• indium–tin–oxide gate electrode