6H-SiC基混合肖特基/PiN二极管反向恢复及少子特性研究  

Reverse recovery and minority carrier characteristic of MPS diodes based on 6H-SiC

作　　者：刘春娟[1] 郑丽君 汪再兴[1] 穆洲 LIU Chunjuan;ZHENG Lijun;WANG Zaixing;MU Zhou(School of Electronics and Information Engineering,Lanzhou Jiaotong University,Lanzhou 730070,China)

机构地区：[1]兰州交通大学电子与信息工程学院,甘肃兰州730070

出　　处：《电子元件与材料》2020年第10期52-58,82,共8页Electronic Components And Materials

基　　金：甘肃省自然科学基金(1610RJZA046)。

摘　　要：反向恢复特性是衡量混合肖特基/PiN(MPS)二极管开关性能最重要的参数之一。本文对6H-SiC基MPS二极管结构参数与反向恢复峰值电流、反向恢复电压之间的关系进行了数值模拟仿真,分析了器件关断过程中过剩少数载流子分布,以此就6HSiC基MPS器件结构参数对反向恢复特性的影响进行了研究。结果表明:结构参数P+区结深、P+区掺杂浓度的增加,或肖特基区占比的减小,均会引起反向恢复峰值电流、反向恢复峰值电压的增大。究其根本,是器件结构参数改变引起了漂移区下少数载流子发生产生、复合、抽运等一系列变化。综合考虑反向恢复峰值电流、反向恢复峰值电压与软恢复特性,得出6H-SiC基MPS最佳优化参数:P+结深为3.8~4.0μm,肖特基区的占比为48%~56%,P+掺杂浓度为5.0×1018/cm3。Reverse recovery characteristics is one of the most important parameters for the switching performance of hybrid Schottky/PiN(MPS)diode.In this paper,the peak current and voltage were numerically simulated,which show strong dependence on the structure parameters of 6H-SiC based MPS diode.Excess minority carrier distribution in drift region was also analyzed.The structure dependent recovery characteristics of the diode was carefully studied.The results show that the reverse recovery peak current and voltage are increased either with the P+junction depth and doping concentration in the P+region or with proportion reduction of Schottky contact area.The fundamental reason is that the change of the structure parameters result in a series of changes of minority carrier in the drift region,such as generation,recombination and pumping.The appropriate structure parameters were obtained by the trade-off between reverse recovery and softness as follow:P+junction depth from 3.8μm to 4.0μm,Schottkey area proportion from 48%to 56%,and P+doping concentration of 5.0×1018/cm3.

关 键 词：6H-SiC MPS 反向恢复峰值电流 反向恢复峰值电压 少数载流子 软恢复因子 

分 类 号：TN510.30[电子电信]