Demonstration of Low-Leakage-Current Low-On-Resistance 600-V 5.5-A GaN/AlGaN HEMT

This letter demonstrates a high-voltage, high-current, and low-leakage-current GaN/AlGaN power HEMT with $\hbox{HfO}_{2}$ as the gate dielectric and passivation layer. The device is measured up to 600 V, and the maximum on-state drain current is higher than 5.5 A. Performance of small devices with $\hbox{HfO}_{2}$ and $\hbox{Si}_{3}\hbox{N}_{4}$ dielectrics is compared. The electric strength of gate dielectrics is measured for both $ \hbox{HfO}_{2}$ and $\hbox{Si}_{3}\hbox{N}_{4}$. Devices with $\hbox{HfO}_{2}$ show better uniformity and lower leakage current than $\hbox{Si}_{3}\hbox{N}_{4}$ passivated devices. The 5.5-A $\hbox{HfO}_{2}$ devices demonstrate very low gate (41 nA/mm) and drain (430 nA/mm) leakage-current density and low on-resistance (6.2 $\Omega \cdot \hbox{mm}$ or 2.5 $\hbox{m}\Omega\cdot \hbox{cm}^{2}$).