The Study of Displacement Damage in AlGaN/GaN High Electron Mobility Transistors Based on Experiment and Simulation Method

This article investigates the displacement damage on AlGaN/GaN high-electron-mobility transistors (HEMTs) using the 30-MeV fluorine ions. The electrical degradation and the defects in HEMTs were examined before and after irradiation. Three defect states are detected in a deep-level transient analysis system (DLTS), including a broad surface state peak (
$N_{1}$
) and two bulk defect peaks (
$H_{1}$
and
$H_{2}$
). The energy levels of these two defects are
$E_{\mathrm {C}} 0.63$
eV (
$H_{2}$
) and
$E_{\mathrm {C}} 0.91$
eV (
$H_{1}$
), respectively. There is a linear relationship between the concentration of
$H_{1}$
and the fluorine ion fluence. The radiation damage and electrical performance degradation of AlGaN/GaN HEMTs are simulated by combining with simulation software of different methods. The calculated results are in agreement with the experimental data. The performance degradation caused by heavy ion of the device is mainly caused by the
$H_{1}$
defect. The effect of defects with shallow energy level is shielded by the Fermi-level pinning in deeper energy level. Moreover, the defect distribution of GaN in AlGaN/GaN heterojunction plays a major role. It is found that the method of combining experimental data with multiscale simulation is an effective way to predict the radiation damage of devices.