Simulation Study on the Impact Mechanism of Traps on AlGaN/GaN HEMT

In this article, the mechanism of the influence of concentration and energy levels of traps in the GaN buffer layer on the saturation current and threshold voltage of depletion-mode GaN HEMT devices is investigated. The GaN HEMT device was simulated and calibrated through sentaurus TCAD software. By introducing a trap model and systematically studying the effects of trap parameters such as concentrations and energy levels, the influence of these traps on the electrical properties of GaN HEMT was studied. The results showed that these traps will cause the degradation of GaN HEMT devices, mainly manifested as a reduction in saturation current and a positive shift in threshold voltage. As the concentration of traps increases, the electrical characteristics of GaN HEMT degrade more seriously. In addition, deep level traps have a stronger ability to capture electrons than trap states in shallow energy levels, and have a more obvious impact on saturation current and threshold voltage. The research findings provide important theoretical guidance for optimizing device fabrication and trap management, and help to further improve the reliability and performance of GaN HEMT devices.