In this work, fast sweeping characterization with an extremely short relaxation time was used to probe the ${V}_{\text {TH}}$ instability of p-GaN gate HEMTs. As the ${I}_{\text {D}}$ - ${V}_{\text {G}}$ sweeping time deceases from 5 ms to $5~\mu \text{s}$ , the ${V}_{\text {TH}}$ dramatically degenerates from 3.13 V to 1.76 V, meanwhile the hysteresis deteriorates from 22.6 mV to 1.37 V. Positive bias temperature instability (PBTI) measurement by fast sweeping shows the ${V}_{\text {TH}}$ features a very fast shifting process but a slower recovering process. D-mode HEMTs counterpart without Mg contamination demonstrates a negligible ${V}_{\text {TH}}$ shift and hysteresis, proving the ${V}_{\text {TH}}$ instability is probably due to the ionization of acceptor-like traps in the p-GaN depletion region. Finally, the ${V}_{\text {TH}}$ instability is verified by a GaN circuit under switching stress. The ${V}_{\text {TH}}$ instability under different sweeping speed uncovers the fact that the high ${V}_{\text {TH}}$ by conventionally slow DC measurements is probably artificial. The DC ${V}_{\text {TH}}$ should be high enough to avoid HEMT faulty turn-on.

中文翻译：

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通过快速扫描表征观察 p-GaN 栅极 HEMT 的动态 VTH

在这项工作中，使用极短弛豫时间的快速扫描表征来探测 ${V}_{\text {TH}}$ p-GaN 栅极 HEMT 的不稳定性。作为 ${I}_{\text {D}}$ —— ${V}_{\text {G}}$ 扫描时间从 5 ms 减少到 $5~\mu \text{s}$ ， 这 ${V}_{\text {TH}}$ 从 3.13 V 急剧下降到 1.76 V，同时滞后从 22.6 mV 下降到 1.37 V。通过快速扫描的正偏置温度不稳定性 (PBTI) 测量显示 ${V}_{\text {TH}}$ 具有非常快的换档过程，但恢复过程较慢。没有 Mg 污染的 D 模式 HEMT 对应物表明可以忽略不计 ${V}_{\text {TH}}$ 偏移和滞后，证明 ${V}_{\text {TH}}$ 不稳定性可能是由于 p-GaN 耗尽区中类受体陷阱的电离。最后， ${V}_{\text {TH}}$ 开关应力下的 ​​GaN 电路验证了不稳定性。这 ${V}_{\text {TH}}$ 不同清扫速度下的不稳定性揭示了高 ${V}_{\text {TH}}$ 传统的缓慢直流测量可能是人为的。直流电 ${V}_{\text {TH}}$ 应足够高以避免 HEMT 错误开启。