This work studies the dynamic breakdown voltage (BV) and overvoltage margin of a 650-V-rated commercial GaN power HEMT in hard switching. The dynamic BV measured in the hard switching circuits is over 1.4 kV, being 450 V higher than the static BV measured in the quasi-static I-V sweep. The device can survive at least 1 million hard-switching overvoltage pulses with 1.33 kV peak overvoltage (~95% dynamic BV). Recoverable device parametric shifts are observed after the 1-million pulses, featuring small reductions in threshold voltage and on-resistance. These shifts are different from the ones after the hard-switching pulses without overvoltage and are attributable to the trapping of the holes produced in impact ionization. These results suggest that the BV and overvoltage margin of GaN HEMTs in practical power switching can be significantly underestimated using the static BV.

中文翻译：

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硬开关中GaN电源HEMT的真击穿电压和过压裕度

这项工作研究了硬开关中额定650V的商用GaN电源HEMT的动态击穿电压（BV）和过压裕量。硬开关电路中测得的动态BV超过1.4 kV，比准静态IV扫描中测得的静态BV高450V。该器件可承受至少100万个具有1.33 kV峰值过电压（〜95％动态BV）的硬开关过电压脉冲。在100万个脉冲之后，观察到可恢复的设备参数变化，其特征在于阈值电压和导通电阻的减小很小。这些位移与没有过电压的硬开关脉冲之后的位移不同，这归因于碰撞电离过程中产生的空穴的俘获。