Geant4在中子辐射效应中的应用

Geant4 Application in Neutron Radiation Effects

中子辐射效应是半导体器件在辐射环境中损伤的重要因素。本文建立了中子在半导体材料中的电离和非电离能量沉积、原子空位密度的Geant4模拟方法。电离能量沉积可用于分析电离总剂量效应,非电离能量沉积可用于分析位移损伤效应。电离kerma因子的模拟结果定量解释了中子辐照在CMOS工艺单片机中引起的电离增强效应。通过原子空位密度计算了中子引入的附加陷阱密度,分析了位移损伤对电离效应的增强作用。实验和模拟结果表明,中子的电离能量沉积加剧了CMOS工艺单片机的退化。

Neutron radiation effect is one of the important reasons which cause semiconductor devices damage in radiation environment.The Geant4 simulation method of ionizing energy loss（IEL）,non-ionizing energy loss（NIEL） and atom vacancies density induced by neutron was introduced in this paper.IEL can be used to analyze total ioniz-ing dose effect,while NIEL can be used to analyze displacement damage.IEL kerma（kinetic energy released in material） factor quantitatively explained the enhanced ioniz-ing effect of CMOS microprocessor induced by neutron radiation.Using atom vacancies density simulation results,additional trap density induced by neutron was calculated,and the enhancement influence on ionizing effect from displacement damage was researched.The experiment and simulation results show that the ionizing energy deposition induced by neutron causes the accelerated degradation of CMOS microprocessor.