基极注入强电磁脉冲对双极晶体管的损伤效应和机理

建立了双极晶体管(BJT)在强电磁脉冲作用下的二维电热模型, 对处于有源放大区的BJT在基极注入强电磁脉冲时的瞬态响应进行了仿真. 结果表明, BJT烧毁点位置随注入脉冲幅度变化而变化, 低脉冲幅度下晶体管烧毁是由发射结反向雪崩击穿所致, 烧毁点位于发射结柱面区; 而在高脉冲幅度下, 由基区-外延层-衬底组成的p-n-n⁺ 二极管发生二次击穿导致靠近发射极一侧的基极边缘率先烧毁; BJT的烧毁时间随脉冲幅度升高而减小, 而损伤能量则随之呈现减小-增大-减小的变化趋势, 因而存在一个极小值和一个极大值. 仿真与实验结果的比较表明, 本文建立的晶体管模型不但能预测强电磁脉冲作用下BJT内部烧毁发生的位置, 而且能够得到损伤能量.关键词：双极晶体管强电磁脉冲烧毁点位置损伤能量

The damage effect and mechanism of bipolar transistors induced by injection of electromagnetic pulse from the base

A two-dimensional electrothermal model of the bipolar transistor (BJT) is established, and the transient behaviors of the BJT originally in the forward-active region are simulated with the injection of electromagnetic pulse from the base. The results show that the damage location of the BJT shifts with the amplitude of the pulse. With a low pulse amplitude, the burnout of the BJT is caused by the avalanche breakdown of the emitter-base junction, and the damage location lies in the cylindrical region of this junction. With a high pulse amplitude, the damage first occurs at the edge of the base closer to the emitter due to the second breakdown of the p-n-n⁺ structure composed of the base, the epitaxial layer and the substrate. The burnout time increases with pulse amplitude increasing, while the damage energy changes in a decrease-increase-decrease order with it, thus generating both a minimum value and a maximum value of the damage energy. A comparison between simulation results and experimental ones shows that the transistor model presented in the paper can not only predict the damage location in the BJT under intense electromagnetic pulses, but also obtain the damage energy.