摘要
碳化硅(SiC)材料因其在禁带宽度、击穿电场、电子饱和速度等方面的优势,使得SiC MOSFET具有高频、高压以及高温等优势。然而SiC MOSFET的特殊材料、结构以及高开关速度使得开关瞬态过程中器件内部的物理机理更为复杂。传统的SiC MOSFET模型沿用了部分硅(Si)器件的建模方法,难以准确评估器件在装置中的动静态特性。为此,该文提出一种基于物理的SiC MOSFET改进电路模型。基于器件的工作机理,分析传统SiC MOSFET模型的不足,并针对不足进行改进建模。电流扩散方式是影响SiCMOSFET静态特性的重要因素,由于器件N-漂移区较窄,导致漂移区电流扩散呈梯形,进而对漂移区电阻进行改进建模。SiC MOSFET开关瞬态模型刻画了器件的高频应用特性,基于突变结、穿通特性以及负电压关断分别对器件结电容进行改进建模。最后基于CREE 1200V/325A的SiC MOSFET器件进行实验,仿真与实验具有较好的一致性,验证了改进模型的准确性。
SiC MOSFET has advantages of high frequency,high voltage and high temperature due to its material advantages in bandgap width,breakdown electric field and electron saturation speed.However,the special material,structure and high-switching speed of SiC MOSFET make the internal physical mechanism of the device more complicated during the switching transient.The traditional SiC MOSFET model adopted the modeling methods of some Si devices,and it is difficult to accurately evaluate the dynamic and static characteristics of the device.Therefore,an improved physics-based SiC MOSFET circuit model is proposed in this paper.Firstly,the shortcomings of the traditional SiC MOSFET model are analyzed and improved based on the operation principles of the device.The mode of current diffusion is an important factor affecting the static characteristics of the SiC MOSFET.The current diffusion in the N-region are trapezoid due to the narrow N-drift region.Hence,the drift region resistance model is improved.The transient model of the SiC MOSFET describes the high-frequency application characteristics of the device.Then junction capacitance models of the SiC MOSFET are improved based on the abrupt junction,punch-through condition and negative-voltage turn-off characteristics.Finally,experiments are carried out on a CREE SiC MOSFET(1200V/325A).Simulation and experiment are in a good agreement,which verifies the effectiveness and accuracy of the improved model.
作者
李鑫
罗毅飞
史泽南
王瑞田
肖飞
Li Xin;Luo Yifei;Shi Zenan;Wang Ruitian;Xiao Fei(National Key Laboratory of Science and Technology on Vessel Integrated Power System Naval University of Engineering,Wuhan 430033 China;College of Electrical Engineering Xi’an Jiaotong University,Xi’an 710049 China)
出处
《电工技术学报》
EI
CSCD
北大核心
2022年第20期5214-5226,共13页
Transactions of China Electrotechnical Society
基金
JCJQ计划(2020-JCJQ-ZD-105)
国家重点研发计划(2019YFC0119101)资助项目。
