Influence of p-GaN gate airgap in p-GaN AlGaN/GaN HEMTs for improved DC performance

This study proposes a novel p-GaN AlGaN/GaN high-electron-mobility transistor (HEMT) structure incorporating a gate airgap to address gate leakage and high electric field issues. Comprehensive device simulations conducted using COMSOL Multiphysics show that the airgap-integrated design enhances the breakdown voltage by 47.7% and reduces gate leakage current by 15% compared to conventional devices. These improvements stem from the redistribution and suppression of peak electric fields near the gate edge, alleviating common leakage mechanisms typically observed in HEMTs. Additionally, the modified structure supports a 35% increase in maximum drain current while maintaining a threshold voltage near 0 V, which is favorable for fail-safe operation in power applications. These findings highlight the promise of gate airgap integration as an effective design strategy for enhancing the performance and long-term reliability of AlGaN/GaN HEMTs in future high-power electronics.