不同发射极面积npn晶体管高低剂量率辐射损伤特性

影响npn晶体管辐射损伤的因素有很多，如晶体管工艺、剂量率以及辐照偏置等.主要研究了三种发射极面积的国产npn晶体管在高低剂量率下的辐射损伤特性，分析了发射极尺寸对辐射损伤的影响.研究结果表明，国产npn晶体管具有低剂量率损伤增强效应，且发现当小电流注入下晶体管的辐射损伤会表现得愈加显著.比较三种发射极尺寸的晶体管辐照响应发现，发射极周长面积比P/A越大时晶体管归一化过剩基极电流ΔI_B/I_B0也越大.详细阐述了npn晶体管辐射损伤机制，从发射极尺寸和晶体管工作电压角度对npn晶体管的加固保证方法进行了探索. 关键词： 发射极面积 国产npn晶体管 剂量率 辐射损伤

Characteristics of high- and low-dose-rate damage for domestic npn transistors of various emitter areas

There are many factors such as process technologies, dose rates and biased conditions which can affect radiation damage in npn transistors. High- and low-dose-rate radiation response of domestic npn transistors with three kinds of emitter areas were investigated in this article. The influence of emitter area on radiation damage was analyzed. The results show that the degradation of current gain was more severe at low dose rate, i.e. enhanced low-dose-rate sensitivity. Furthermore, radiation damage was more apparent at low current injection. Through the comparison of radiation damage for different emitter areas, it was found that greater perimeter-to-area ratio （P/A） would cause greater normalized excess base current （I_B/I_B0）. The damage mechanism for npn transistors is explained in detail, and the radiation hardness assurance is explored with respect to the emitter area and operating voltage of npn transistors.