基于1/f噪声的NPN晶体管辐照感生电荷的定量分离  

Quantitative separation of radiation induced charges for NPN bipolar junction transistors based on 1/f noise model

作　　者：赵启凤[1] 庄奕琪[1] 包军林[1] 胡为[2] 

机构地区：[1]西安电子科技大学微电子学院,西安710071 [2]西安电子科技大学机电工程学院,西安710071

出　　处：《物理学报》2015年第13期301-307,共7页Acta Physica Sinica

基　　金：国家自然科学基金(批准号:61076101;61204092)资助的课题~~

摘　　要：本文针对NPN双极性晶体管,在研究辐照感生的氧化层电荷及界面态对晶体管基极电流和1/f噪声的影响的基础上,建立辐照感生氧化层电荷及界面态与基极电流和1/f噪声的定量物理模型.根据所建立的模型,提出一种新的分离方法,利用1/f噪声和表面电流求出氧化层电荷密度,利用所求得氧化层电荷密度和表面电流求出界面态密度.利用本方法初步实现了辐照感生氧化层电荷及界面态的定量计算.Ionizing-radiation-induced oxide-trapped charges and interface states cause the current and 1/f noise degradation in bipolar junction transistors. In order to better understand these two degradation mechanisms and develop hardening approaches for a specific process technology, it is necessary to measure the effect of each mechanism separately. In recent years, several techniques have been developed, but no charge-separation approach based on 1/f noise for NPN bipolar junction transistors is available. In this paper, the effects of ionizing-radiation-induced oxide trapped charges and interface states on base current and 1/f noise in NPN bipolar junction transistors are studied in detail. Firstly, a new model of base surface current of NPN bipolar junction transistors is presented with some approximations, based on an available model for the base surface current under certain conditions;this model can identify the physical mechanism responsible for the current degradation. Secondly, combining the theory of carrier number fluctuation and the new model of base surface current another model is developed which can well explain the 1/f noise degradation. This model suggests that the induced oxide-trapped charges would make more carriers, involving the dynamic trapping-detrapping, which leads to the 1/f noise to increase; and the induced oxide-trapped charges and interface states can also bring about an increase in base surface current which can also cause the l/f noise increase. These two models suggest that the current and1/f noise degradations can be attributed to the same physical origin, and these two kinds of degradations are the result of accumulation of oxide-trapped charges and interface states. According to these two models, simple approaches for quantifying the effects of oxide-trapped charges and interface states are proposed. The base surface current can be extracted from the base current using the available method. The oxide-trapped charge density is estimated using the amplitude of 1/f noise （10—100 Hz

关 键 词：电离辐照 1/f噪声 氧化层电荷 界面态 

分 类 号：TN32[电子电信—物理电子学]