We present detailed ON-state gate current characterization of Schottky gate p-GaN capped AlGaN/GaN high-electron-mobility transistors (HEMTs) on two distinct gate processes. The threshold voltage is monitored from 10 μs up to 100 s under positive gate bias stress and during recovery. The threshold voltage stability is affected by the balance between hole and electron current in the gate stack. More specifically, devices with uniform hole conduction across the p-GaN gate area demonstrate stable threshold voltage behavior up to Vg = 5 V, whereas devices with a dominating gate perimeter electron conduction demonstrate larger instabilities. Finally, the threshold voltage stability during OFF-state pulsed stress is investigated and correlated to the excess gate-to-drain charge extracted from capacitance curves.

中文翻译：

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p-GaN 栅极 AlGaN/GaN HEMT 中肖特基栅极引起的阈值电压不稳定性


我们展示了两种不同栅极工艺上肖特基栅极 p-GaN 盖帽 AlGaN/GaN 高电子迁移率晶体管 (HEMT) 的详细导通状态栅极电流特性。在正栅极偏压应力下和恢复期间，对阈值电压进行 10 μs 至 100 s 的监控。阈值电压稳定性受到栅堆叠中空穴和电子电流之间的平衡的影响。更具体地说，p-GaN 栅极区域上具有均匀空穴传导的器件表现出高达 Vg = 5 V 的稳定阈值电压行为，而具有主导栅极周边电子传导的器件表现出更大的不稳定性。最后，研究了关态脉冲应力期间的阈值电压稳定性，并将其与从电容曲线中提取的过量栅漏电荷相关联。