Silicon-carbide metal–oxide–semiconductor field-effect transistors (SiC-MOSFETs) are core devices for future power electronics. The factors limiting their automotive applications are currently under investigation. Postoxidation annealing in NO gas is a key technology to achieving high carrier mobility in SiC-MOSFETs. In this article, we study the NO annealing effects on time-dependent dielectric breakdown (TDDB) reliability by the constant voltage stress (CVS) method at room temperature (RT). We show that heavy NO annealing enhances hole trapping near the SiO ₂ /SiC interface and leads to a rapid increase in the gate current ( $I_{\text {g}}$ ) and results in shorter time-to-breakdown ( $t_{\text {BD}}$ ) and smaller Weibull slope of $t_{\text {BD}}$ in comparison to light NO annealing case. However, the detailed examination of the $I_{\text {g}}$ behavior reveals that the charge-to-breakdown ( $Q_{\text {BD}}$ ) and its distribution do not deteriorate. Therefore, we must reconsider the use of the CVS method by examining the $I_{\text {g}}$ behavior during stress, which strongly depends on NO annealing conditions.

中文翻译：

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NO退火的SiC-MOSFET中恒定电压应力引起的栅极电流和TDDB寿命的异常行为

碳化硅金属氧化物半导体场效应晶体管（SiC-MOSFET）是未来电力电子设备的核心器件。目前正在研究限制其汽车应用的因素。NO气体中的后氧化退火是在SiC-MOSFET中实现高载流子迁移率的关键技术。在本文中，我们通过室温（RT）下的恒定电压应力（CVS）方法研究了NO退火对时间相关介电击穿（TDDB）可靠性的影响。我们发现，大量的NO退火会增强SiO ₂ / SiC界面附近的空穴陷阱， 并导致栅极电流快速增加（ $ I _ {\ text {g}} $ ），从而缩短了故障发生时间（ $ t _ {\ text {BD}} $ ）和较小的Weibull坡度 $ t _ {\ text {BD}} $ 与轻型NO退火情况相比。但是，详细检查 $ I _ {\ text {g}} $ 行为表明，要进行细分的费用（ $ Q _ {\ text {BD}} $ ）及其分布不会恶化。因此，我们必须通过检查 $ I _ {\ text {g}} $ 应力过程中的行为，这在很大程度上取决于NO退火条件。