The Drift Region Width Modulation Technique for Breakdown Performance Enhancement of AlGaN/GaN HEMT

The breakdown performance of the AlGaN/GaN high electron mobility transistor (HEMT) is limited by the high electric field peaks in the device. To obtain a more uniform electric field distribution, the drift region width modulation (DWM) technique is proposed to reshape the charge distribution between the gate and drain electrodes. By applying the Gaussian box method, an effective designing guidance for the structure optimization of the AlGaN/GaN HEMT with adaptive-width drift region pillars (AWD-HEMT) is obtained. The fabricated AWD-HEMT demonstrated a significant improvement in breakdown performance. The Baliga's figure of merit (BFOM) of AWD-HEMT improved 65.3% compared with the conventional HEMT, without introducing complicated processes. In addition, the mechanism of the AWD-HEMT is explored by numerical methods. The simulations indicate that a more uniform electric field distribution at AlGaN/GaN interfaces could be obtained, and the increased varying rate of the adaptive-width drift region (AWD) pillars results in a more obvious electric field modulation effect.