TCAD Modeling of the Dynamic $V_{TH}$ Hysteresis Under Fast Sweeping Characterization in p-GaN Gate HEMTs

TCAD modeling of the dynamic threshold voltage shift (hysteresis) occurring under fast sweeping characterization in Schottky-type p-GaN gate high-electron-mobility transistors (HEMTs) is reported, to the best of our knowledge, for the first time. Dynamic $V_{TH}$ hysteresis has been first experimentally characterized under different sweeping times, temperatures, and AlGaN barrier configurations. Then, TCAD simulations have been carried out, reproducing the experimental evidences and understanding the microscopic mechanisms responsible for such effect. In particular, nonlocal tunneling models implemented in Sentaurus TCAD, defined at the gate Schottky contact and assisted by traps in the AlGaN barrier layer, have been adopted and properly tuned against experiments. Results show that the dynamic $V_{TH}$ hysteresis is mainly caused by the time-dependent hole charging/discharging processes in the floating p-GaN layer, which are governed by the Schottky and AlGaN barrier leakage current components.

Automated summary

This study reports for the first time the TCAD modeling of dynamic threshold voltage shift in Schottky-type p-GaN gate HEMTs under fast sweeping characterization. The experimental characterization and TCAD simulations demonstrate that the dynamic V_TH hysteresis is mainly influenced by time-dependent hole charging/discharging processes in the floating p-GaN layer.