The influence of morphological defects on long-term reliability of 1200-V/40-A 4H-SiC junction barrier Schottky (JBS) diodes under the 668 h of reverse bias stress (RBS) is investigated in depth. The variation of electrical properties and related degradation mechanisms is analyzed. It is found that the breakdown voltage ( ${V}_{\text {BR}}$ ) increment of the samples containing morphological defects is significantly larger than that of samples without defects after RBS. Moreover, the specific on-resistance ( ${R}_{\text {sp}}$ ) of the former increases with the increase in stress time due to the increase in ideal factor (n) and the decrease in barrier height ( $\Phi _{\text {B}}$ ). The C–V characteristics and simulation results demonstrate that the hole injection in the SiO2/SiC interface of edge termination could be responsible for the observed variation of ${V}_{\text {BR}}$ after RBS. In addition, further analysis indicate that the trap energy levels related to the morphological defects contribute to the process of trapping carriers at the interface, and the degradation mechanism of the forward and reverse characteristics of 4H-SiC JBS under RBS is revealed by the energy band model.

中文翻译：

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缺陷对1200-V/40-A 4H-SiC结势垒肖特基二极管高储备偏置应力劣化机理的影响分析

深入研究了形态缺陷对1200V/40A 4H-SiC结势垒肖特基(JBS)二极管在668小时反向偏压(RBS)下的长期可靠性的影响。分析了电性能的变化和相关的退化机制。发现击穿电压（ ${V}_{\text {BR}}$ ）经RBS处理后，含有形态缺陷的样品增量明显大于无缺陷样品。此外，特定的导通电阻（ ${R}_{\text {sp}}$ 由于理想因子 (n) 的增加和势垒高度的降低 ( $\Phi _{\text {B}}$ ）。 C-V 特性和模拟结果表明，边缘终止的 SiO2/SiC 界面中的空穴注入可能是观察到的变化的原因 ${V}_{\text {BR}}$苏格兰皇家银行之后。此外，进一步分析表明，与形态缺陷相关的陷阱能级有助于界面处载流子的俘获过程，并通过能带揭示了4H-SiC JBS在RBS下正向和反向特性的退化机制。模型。