We report on the correlation between the electroluminescence and current collapse of AlGaN/GaN high-electron-mobility transistors (HEMTs). Standard passivated devices suffering from severe current collapse exhibited high-intensity whitish electroluminescence confined near the drain contact. In contrast, devices with reduced current collapse resulting from oxygen plasma treatment or GaN capping showed low-intensity reddish emission across the entire gate–drain access region. A qualitative explanation of this observed correlation between the current collapse and electroluminescence is presented. Our results demonstrate that electroluminescence analysis is a powerful tool not only for identifying high-field regions but also for assessing the degree of current collapse in AlGaN/GaN HEMTs.

We investigated the impact of rounded electrode corners on the breakdown characteristics of AlGaN/GaN high-electron mobility transistors. For standard reference devices, catastrophic breakdown occurred predominantly near the sharp electrode corners. By introducing a rounded-electrode architecture, premature breakdown at the corners was mitigated. Moreover, the rate of breakdown voltage (VBR) degradation with an increasing gate width (WG) was significantly lower for devices with rounded corners. When WG was increased from 100 µm to 10 mm, the VBR of the reference device dropped drastically, from 1,200 to 300 V, whereas that of the rounded-electrode device only decreased to a respectable value of 730 V.

This paper describes breakdown characteristics of AlGaN/GaN high electron mobility transistors (HEMTs) with multi-finger gate patterns. We studied the spatial profile of electroluminescence (EL) from AlGaN/GaN HEMTs under high drain and near pinch-off gate bias. As a result, different EL emission profiles and breakdown characteristics were observed depending on the drain electrode pattern of the devices.

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