Suppression of Gate Leakage and Enhancement of Breakdown Voltage Using Thermally Oxidized Al Layer as Gate Dielectric for AlGaN/GaN Metal–Oxide–Semiconductor High-Electron-Mobility Transistors

This is the authors' abstract. We don't add key points for this paper.

A synthetic route for alumina based dielectric layer for AlGaN/GaN metal–oxide–semiconductor high-electron-mobility transistors (MOS-HEMT) has been developed. The approach is based on oxidative annealing of thin Al layer deposited prior to Schottky gate metallization. The MOS-HEMT exhibits good pinch off features with I dsmax and g mmax of 421 mA/mm and 121 mS/mm, respectively. Frequency dependent conductance measurements yielded a minimum trap density ( D T ) and trap transient time ( T T ) of 2.2 × 10 12 cm -2 eV -1 and 1.3 µs, respectively. The oxide layer suppresses the gate leakage by two orders of magnitude and enhances the breakdown voltage ( BV ) of the devices. A high BV of 431 V and figure of merit (FOM) of 1.89 × 10 8 V 2 Ω -1 cm -2 for 15 µm device at ( L gd ≤4 µm) was observed for Al 2 O 3 based MOS-HEMT.