In this article, an analytical I–V model for calculating subthreshold current of SiC MOSFETs is presented. This model starts with planar MOSFETs and utilizes the one-dimensional Poisson’s equation to derive an analytical expression for the surface potential. Subsequently, it employs this expression as a foundation for subthreshold current calculations. Then the model is extended to DMOSFETs based on the fact that channel current formation mechanism of DMOSFETs is similar to that of planar MOSFETs. Comparative analysis of our model calculations with two-dimensional numerical simulation software reveals that our model exhibits a high degree of agreement in the case of planar MOSFETs and DMOSFETs. Interface traps were also considered in our analytical model, which agrees well with experimental data published elsewhere. Furthermore, the model retains a certain degree of accuracy and predictive capability even in the presence of short-channel effect. Our subthreshold model becomes complementary to existing models which only describe the I–V characteristics of SiC MOSFETs when the transistors operate above the threshold voltages.

中文翻译：

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SiC MOSFET 的亚阈值 I-V 分析模型

本文提出了用于计算 SiC MOSFET 亚阈值电流的分析 I-V 模型。该模型从平面 MOSFET 开始，利用一维泊松方程导出表面电势的解析表达式。随后，它采用该表达式作为亚阈值电流计算的基础。然后基于DMOSFET沟道电流形成机制与平面MOSFET相似的事实，将该模型扩展到DMOSFET。我们的模型计算与二维数值仿真软件的比较分析表明，我们的模型在平面 MOSFET 和 DMOSFET 的情况下表现出高度的一致性。我们的分析模型也考虑了界面陷阱，这与其他地方发表的实验数据非常吻合。此外，即使存在短通道效应，该模型仍保留一定程度的准确性和预测能力。我们的亚阈值模型成为对现有模型的补充，现有模型仅描述 SiC MOSFET 当晶体管在阈值电压以上工作时的 I-V 特性。