Degradation characteristics of AlGaN-GaN high electron mobility transistors

AlGaN-GaN high electron mobility transistors (HEMTs) have shown great potential for high temperature/high power electronics. However, the study on the reliability of GaN-based devices is still at the initial stages. In this work, we report the degradation characteristics of AlGaN HEMTs under various stress conditions such as DC stress (gate current extraction and hot electron cycles) and RF input drive stress at room temperature. While AlGaN-GaN HEMTs have shown robust reliabilities under gate current extraction stress, degradation due to hot carriers was observed under hot electron cycles and RF input drive stress. Si₃N₄ passivation was found to provide better reliability than SiO₂ passivation under DC stress and RF input drive stress