Although gate-oxide degradation occurs in both silicon (Si) and silicon carbide (SiC) MOSFETs, it requires a special attention in SiC MOSFETs. This is because the gate oxide in SiC MOSFETs is comparatively thinner than the gate oxide in Si MOSFETs, and thus, a higher electric field that appears across it could push the gate oxide to its reliability limit. While several electrical parameters have been identified as precursors (indicators) for monitoring the gate-oxide degradation process in Si MOSFETs, very few have been identified for their SiC counterparts. The purpose of this article is twofold. The first objective is to demonstrate that the three gate-oxide degradation precursors identified for Si MOSFETs: 1) threshold voltage, 2) gate-plateau voltage, and 3) gate-plateau time can also be extended to SiC MOSFETs. The second objective is to demonstrate analytically and experimentally that all three precursors increase in a linear-with-log-stress-time manner during gate-oxide degradation in both planar and trench-gate SiC MOSFETs. The increasing trends of precursors and their associated logarithmic time responses were experimentally verified by inducing accelerated gate-oxide degradation in two different commercial SiC MOSFETs (650-V, 70-A trench-gate MOSFETs and 1200-V, 19-A planar MOSFETs) under high temperatures of 150 and 125 °C, respectively.

中文翻译：

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栅极氧化物降解对碳化硅 MOSFET 电参数的影响

尽管在硅 (Si) 和碳化硅 (SiC) MOSFET 中都会发生栅极氧化物退化，但在 SiC MOSFET 中需要特别注意。这是因为 SiC MOSFET 中的栅极氧化物比 Si MOSFET 中的栅极氧化物更薄，因此，在其两端出现的更高电场可能会将栅极氧化物推向其可靠性极限。虽然一些电气参数已被确定为用于监测 Si MOSFET 中栅极氧化层退化过程的前体（指标），但很少有人确定其 SiC 对应物。这篇文章的目的是双重的。第一个目标是证明为 Si MOSFET 确定的三个栅极氧化物退化前体：1) 阈值电压，2) 栅极平台电压和 3) 栅极平台时间也可以扩展到 SiC MOSFET。第二个目标是通过分析和实验证明，在平面和沟槽栅极 SiC MOSFET 的栅极氧化物退化期间，所有三种前驱物均以线性对数应力时间方式增加。通过在两种不同的商用 SiC MOSFET（650-V、70-A 沟槽栅极 MOSFET 和 1200-V、19-A 平面 MOSFET）中诱导栅极氧化层加速退化，通过实验验证了前体的增加趋势及其相关的对数时间响应分别在 150 和 125 °C 的高温下。