In order to evaluate the feasibility of newly developed gallium nitride (GaN) devices in a cryogenically cooled converter, this article characterizes a 650-V enhancement-mode GaN high-electron mobility transistor (GaN HEMT) at cryogenic temperatures. The characterization includes both static and dynamic behaviors. The results show that this GaN HEMT is an excellent device candidate to be applied in cryogenic-cooled applications. For example, transconductance at cryogenic temperature (93 K) is 2.5 times higher than one at room temperature (298 K), and accordingly, peak di/dt during turn-on transients at cryogenic temperature is around 2 times of that at room temperature. Moreover, the ON-resistance of the channel at the cryogenic temperature is only one-fifth of that at room temperature. The corresponding explanations of performance trends at cryogenic temperatures are also given from the view of semiconductor physics. In addition, several device failures were observed during the dynamic characterization of GaN HEMTs at cryogenic temperatures. The ultrafast switching speed-induced high di/dt and dv/dt at cryogenic temperatures amplify the negative effects of parasitics inside the switching loop. Based on failure waveforms, two failure modes were classified, and detailed failure mechanisms caused by ultrafast switching speed are given in this article.

中文翻译：

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低温冷却功率电子器件的650V增强型GaN HEMT的表征和故障分析

为了评估在低温冷却的转换器中新开发的氮化镓（GaN）器件的可行性，本文对低温下的650V增强型GaN高电子迁移率晶体管（GaN HEMT）进行了表征。表征包括静态和动态行为。结果表明，这种GaN HEMT是极好的器件，可用于低温冷却应用。例如，低温（93 K）下的跨导是室温（298 K）下的跨导的2.5倍，因此，低温下开启瞬态期间的峰值di / dt约为室温下的2倍。此外，在低温下通道的导通电阻仅为室温下的导通电阻的五分之一。还从半导体物理学的角度给出了低温下性能趋势的相应解释。此外，在低温下动态表征GaN HEMT的过程中，观察到了一些器件故障。在极低的温度下，超快的开关速度引起的高di / dt和dv / dt会放大开关环路内部寄生效应的负面影响。根据故障波形，分类了两种故障模式，并给出了由超快开关速度引起的详细故障机理。在极低的温度下，超快的开关速度引起的高di / dt和dv / dt会放大开关环路内部寄生效应的负面影响。根据故障波形，分类了两种故障模式，并给出了由超快开关速度引起的详细故障机理。在极低的温度下，超快的开关速度引起的高di / dt和dv / dt会放大开关环路内部寄生效应的负面影响。根据故障波形，分类了两种故障模式，并给出了由超快开关速度引起的详细故障机理。