Model of radiation-induced gain degradation of NPN bipolar junction transistor at different dose rates  

作　　者：赵启凤 庄奕琪 包军林 胡为 

机构地区：[1]School of Microelectronics Xidian University [2]School of Mechano-Electronic Engineering Xidian University

出　　处：《Journal of Semiconductors》2015年第6期68-71,共4页半导体学报（英文版）

基　　金：Project supported by the National Natural Science Foundation of China(Nos.61076101,61204092)

摘　　要：Ionizing-radiation-induced current gain degradation in NPN bipolar junction transistors is due to an increase in base current as a result of recombination at the surface of the device. A model is presented which identifies the physical mechanism responsible for current gain degradation. The increase in surface recombination velocity due to interface states results in an increase in base current. Besides, changing the surface potential along the base surface induced by the oxide-trapped charges can also lead to an increased base current. By combining the production mechanisms of oxide-trapped charges and interface states, this model can explain the fact that the current gain degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 70 krad（Si）. The low dose rate was 0.1 rad（Si）/s and the high dose rate was 10 rad（Si）/s. The model accords well with the experimental results.Ionizing-radiation-induced current gain degradation in NPN bipolar junction transistors is due to an increase in base current as a result of recombination at the surface of the device. A model is presented which identifies the physical mechanism responsible for current gain degradation. The increase in surface recombination velocity due to interface states results in an increase in base current. Besides, changing the surface potential along the base surface induced by the oxide-trapped charges can also lead to an increased base current. By combining the production mechanisms of oxide-trapped charges and interface states, this model can explain the fact that the current gain degradation is more severe at a low dose rate than at a high dose rate. The radiations were performed in a Co60 source up to a total dose of 70 krad（Si）. The low dose rate was 0.1 rad（Si）/s and the high dose rate was 10 rad（Si）/s. The model accords well with the experimental results.

关 键 词：RADIATION bipolar junction transistors current gain degradation model 

分 类 号：TN322.8[电子电信—物理电子学]