摘要
本文针对国产NPN双极晶体管开展了不同偏置下的总剂量辐照试验。试验结果表明,辐照主要导致双极晶体管的基极电流增加和电流增益降低。同时,NPN晶体管在反向偏置下表现出较零偏下更严重的退化。分析发现,双极晶体管性能退化主要来源于辐射诱生缺陷导致的复合电流增加。最后,基于深能级瞬态谱开展了NPN晶体管发射结的缺陷测试,发现辐射会导致缺陷密度的增加和缺陷能级的改变。
In this paper,the total ionize dose(TID)irradiations for NPN bipolar transistors were carried out by ^(60)Co γ rays.Obvious degradations were observed after irradiation,which are manifested as the increase of base current and the decrease of current gain.A more obvious increase of base current was observed at lower emitter junction bias.It shows that the degradation of the base current mainly origins from the increase of the recombination current of the emitter junction,since the recombination current component in base current is dominant at lower emitter junction bias.It can be concluded that the performance degradations of bipolar transistors are mainly due to the increase of recombination current caused by radiation-induced traps in the oxide.It is found that the bias condition during irradiation is the key factor affecting the TID effect of NPN transistor.The reverse bias is a worse bias condition than the zero bias during irradiation.Furthermore,the TID effect of two kinds of NPN bipolar transistors was compared.The two kinds of transistors have the same structure,except that one of the devices is radiation hardened by improving the surface state of the base region.The radiation induced degradations in radiation hardened devices are less than that in unhardened devices.For the unhardened device,the base current increases from 8.82×10^(-8) A to 3.67×10^(-7) A at|V_(EB)|=0.5 V after 50 krad(Si)irradiation,increased by 316%.While for the hardened device,the base current increases from 7.51×10^(-8) A to 1.19×10^(-7) A at|V_(EB)|=0.5 V after 50 krad(Si)irradiation,increased by 58.4%.Finally,the deep level traps in NPN transistors were measured by deep level transient spectrum(DLTS)before and after irradiation.The radiation will increase the trap densities and alter the energy level of the traps for the unhardened devices.By comparing the DLTS results of hardened and unhardened devices,it is found that there are great differences in their native traps.The energy level of the traps in the hardened devices is f
作者
彭超
雷志锋
张鸿
张战刚
何玉娟
PENG Chao;LEI Zhifeng;ZHANG Hong;ZHANG Zhangang;HE Yujuan(Science and Technology on Reliability Physics and Application of Electronic Component Laboratory,China Electronic Product Reliability and Environmental Testing Research Institute,Guangzhou 511370,China)
出处
《原子能科学技术》
EI
CAS
CSCD
北大核心
2022年第10期2187-2194,共8页
Atomic Energy Science and Technology
关键词
双极晶体管
总剂量效应
深能级瞬态谱
辐射损伤缺陷
bipolar transistor
total ionize dose effect
deep level transient spectrum
irradiation damage
