脉冲中子辐照下三极管电流-时间响应曲线的试验研究  

Current-Time Response Characteristics of BipolarTransistors Irradiated by Pulsed Neutron

作　　者：白小燕 刘岩[1,2] 王桂珍 齐超[1,2] 金晓明 李瑞宾[1,2] 王晨辉 李俊霖[1,2] BAI Xiao-yan;LIU Yan;WANG Gui-zhen;QI Chao;JIN Xiao-ming;LI Rui-bin;WANG Chen-hui;LI Jun-lin(State Key Laboratory of Intense Pulsed Radiation Simulation and Effect,Xi’an 710024,China;Northwest Institute of Nuclear Technology,Xi’an 710024,China)

机构地区：[1]强脉冲辐射环境模拟与效应国家重点实验室,西安710024 [2]西北核技术研究所,西安710024

出　　处：《现代应用物理》2020年第4期98-105,共8页Modern Applied Physics

基　　金：强脉冲辐射环境模拟与效应国家重点实验室基金资助项目(SKLIPR1804)。

摘　　要：利用西安脉冲反应堆(XAPR)的脉冲中子进行辐照,在固定发射极电流下,测量了9种类型三极管的电流-时间响应曲线。理论分析认为,可将基极电流的时间响应分为3个阶段:第1阶段基极电流随时间增大而减小,该过程主要受光电流的影响;第2阶段基极电流随时间增大而快速增大,该过程主要受位移损伤缺陷累积作用的影响;第3阶段基极电流随时间增大而减小并趋于稳定,该过程主要受位移损伤缺陷短期退火的影响。基于测量的集电极电流和基极电流,计算了三极管的放大倍数及短期退火曲线。结果表明,9种类型三极管辐照前后放大倍数的变化率之比大于2,但短期退火曲线差别较小,最大退火因子为1.2~1.3,远小于快堆上得到的短期退火因子2~5。分析认为,该结果是因为加电辐照和XAPR脉宽较长造成的,高载流子密度和长脉宽下,脉冲中子辐照期间缺陷的产生与演化同步发生,导致有效的缺陷数量减少,短期退火因子变小。同时,研究发现,短期退火曲线呈指数衰减,这与缺陷演化的一级动力学过程相符。The current-time characteristics of nine types of bipolar transistors with constant emitter current irradiated by pulsed neutron on Xi’an pulsed reactor(XAPR)have been investigated.According to the theoretical analysis of experimental results,the characteristics of base current over time in bipolar transistor can be divided into three phases:first,the base current decreases with time,this phase is dominated by the photo-current;second,the base current increases rapidly with time,this phase is dominated by the accumulation of displacement defects;third,the base current decreases with time and stabilizes,this phase is dominated by the short-term annealing effect of displacement defects.The gain and short-term annealing factors of transistors are calculated based on the base and collector currents,the result shows that the changes of gain in nine types of bipolar transistors before and after the irradiation are within two folds,but the change of short-term annealing factor is smaller,the maximum annealing factor is in the range of 1.2-1.3,which is far smaller than the factor of 2-5 observed in rapid annealing.The numerical simulation shows that this result is caused by the biased irradiation and bigger pulse width on XAPR.With the higher carrier density and the longer pulse width,the generation and annihilation of defects occurred simultaneously and consequently,the number of effective defects decreased and short-term annealing factor became smaller.Furthermore,it is found that the annealing factor exhibits an exponential decrease via time,which is consistent with the first-order kinetic process in defect evolution.

关 键 词：脉冲中子 三极管 电流-时间响应 短期退火 

分 类 号：TL929[核科学技术—核燃料循环与材料] O212[理学—概率论与数理统计]