Charge trapping in gate-drain access region of AlGaN/GaN MIS-HEMTs after drain stress

In this paper we investigate the drain stress behavior and charge trapping phenomena of GaN-based high electron mobility transistors (HEMTs). We fabricated GaN-on-Si MIS-HEMTs with different dielectric stacks in the gate and gate drain access region and performed interface characterization and stress measurements for slow traps analysis. Our results show a high dependency of the on-resistance increase on interfaces in the gate-drain access region. The dielectric interfaces near the channel play a significant role for long term high voltage stress and regeneration of the device.