一种考虑复合电流的SiC LBJT行为模型改进

Improved SiC LBJT Behavior Model Considering Recombination Current

介绍了一种考虑基区SiC/SiO2界面处复合电流的SiC LBJT改进模型。分析了横向碳化硅双极结型晶体管与其垂直结构之间的区别,将横向BJT的外延层和半绝缘机构等效为衬底电容。再引入一个平行于SiC BJT基极结的附加二极管来描述复合电流,以垂直SiC BJT的SGP模型为基础建立SiC LBJT行为模型。校准了LBJT模型的基区渡越时间,模型与实际器件的开关特性接近吻合。相较于未考虑复合电流的LBJT模型,改进后的模型输出特性曲线与实测数据精度误差较小。该模型可以较精确地描述受复合电流影响的LBJT器件行为。

An improved SiC Lateral bipolar junction transistor(LBJT)model considering the recombination current at the SiC/SiO2 interface in the base region is introduced.The difference between the lateral silicon carbide bipolar junction transistor and its vertical structure is analyzed.The epitaxial layer and the semi-insulating mechanism of the lateral BJT are equivalent to the substrate capacitance.An additional diode parallel to the base junction of the SiC BJT is introduced to describe the composite current.The behavior model of SiC LBJT is established based on the SGP model of a vertical SiC BJT.The base transit time of the LBJT model is calibrated,and the switching characteristics of the model are close to those of the actual device.On comparison with the measured data,the accuracy error between the output characteristic curve of the improved model is found to be smaller than that of the comparison with LBJT model data that does not consider the recombination current.This model can accurately describe the behavior of LBJT devices affected by the recombination current.