In this article, we experimentally study the instability of the key electrical characteristic for the fabricated ${\beta }$ -Ga2O3 MOSFET under positive bias stress (PBS) and negative bias stress (NBS), such as threshold voltage ( ${V}_{{\mathrm {TH}}}$ ), ON-resistance ( ${R}_{{\mathrm {on}}}$ ), subthreshold slope (SS), and hysteresis. An ionized traps model is proposed to explain the instability, which depicts the traps and interfaces states capturing/releasing electrons from the channel. We find nonuniform instability mechanisms. Under the PBS of ${V}_{GS} = 4$ V for 1000 s, the ${V}_{{\mathrm {TH}}}$ and ${R}_{{\mathrm {on}}}$ are increased by 0.8 V and 19%, respectively. The constant interface state density indicates that this instability is caused by border traps in the gate oxide capturing electrons from channel. For the NBS of ${V}_{GS} = -4$ V for 1000 s, the variation in the ${V}_{{\mathrm {TH}}}$ and ${R}_{{\mathrm {on}}}$ is −0.54 V and −8.8%, respectively. The instability is attributed to both the border traps and interface states, and the net increase in activated interface states is $2.25\times10$ 11 cm−2 extracted from hysteresis. Unlike the PBS, the interface states release electrons to bulk traps, and thus the activated interface state density changes. A good agreement with experimental results shows that the proposed model could accurately describe the instability mechanism under both PBS and NBS. These results provide guidance for identifying defects, optimizing device structure, and fabrication process to improve the reliability of $\boldsymbol {\beta } $ -Ga2O3 MOSFET.

中文翻译：

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β-Ga2O3 MOSFET正负偏压不稳定性的非均匀机制

在本文中，我们通过实验研究了制造的关键电气特性的不稳定性 ${\beta }$ -Ga2O3 MOSFET在正偏置应力（PBS）和负偏置应力（NBS）下，如阈值电压（ ${V}_{{\mathrm {TH}}}$ ），导通电阻（ ${R}_{{\mathrm {on}}}$ )、亚阈值斜率 (SS) 和滞后。提出了一个电离陷阱模型来解释不稳定性，该模型描述了陷阱和界面状态从通道捕获/释放电子。我们发现不均匀的不稳定机制。根据 PBS ${V}_{GS} = 4$V 为 1000 秒， ${V}_{{\mathrm {TH}}}$和 ${R}_{{\mathrm {on}}}$分别增加 0.8 V 和 19%。恒定的界面态密度表明这种不稳定性是由栅极氧化物中的边界陷阱从沟道捕获电子引起的。对于国家统计局 ${V}_{GS} = -4$V 为 1000 秒，在 ${V}_{{\mathrm {TH}}}$和 ${R}_{{\mathrm {on}}}$分别为 -0.54 V 和 -8.8%。不稳定性归因于边界陷阱和界面态，激活的界面态的净增加是 $2.25\times10$ 从滞后中提取 11 cm-2。与 PBS 不同，界面态将电子释放到体陷阱，因此激活的界面态密度会发生变化。与实验结果的良好一致性表明，所提出的模型可以准确地描述 PBS 和 NBS 下的不稳定性机制。这些结果为识别缺陷、优化器件结构和制造工艺以提高可靠性提供了指导。 $\boldsymbol {\beta } $ -Ga2O3 MOSFET。