4H-SiC MESFET直流I-V特性解析模型

Analytical Model of DC I-V Characteristics of 4H-SiC MESFETs

提出了一种改进的4H-SiC MESFET非线性直流解析模型,基于栅下电荷的二维分布,对该模型进行了分析,采用多参数迁移率模型描述速场关系。在分析了电流速度饱和的基础上,考虑沟道长度调制效应对饱和区漏电流的影响,建立了基于物理的沟道长度调制效应模型,模拟结果符合高场下漏极的MC(蒙特卡罗)计算的结果。与以前的研究模型相比较,结果说明了该研究的有效性,饱和电流的结果与实测的I-V特性更加吻合。

An improved analytical model of nonlinear DC for 4H-SiC MESFETs was developed, and its analysis was based on the 2-D charge distribution under the gate. The multiparameter mobility model was used for describing the velocity-field relationship. With the velocity saturation and channel-length modulation effects taken into consideration, a physical channel-length modulation effect model was built based on the analysis of the current saturation. Simulation results agree well with the drain MC （Monte Carlo） calculation results. Compared with other models studied before, it indicates that the model is valid, and that simulation results of the saturation current agree well with the measured Ⅰ-Ⅴ characteristics in the saturation region.