铁电储存器中子单粒子效应的蒙特卡罗模拟

Montecarlo Simulation about Single Event Effect of Ferroelectric Random Access Memory Induced by Neutron

大气辐射环境中高通量中子对铁电存储器的单粒子效应不容忽视.该文利用蒙特卡罗方法研究了铁电存储器的中子单粒子效应.中子入射在铁电存储器灵敏区域造成的总能量沉积随中子能量的增大而增加,且在灵敏区域内部的总能量沉积值略大于在边界处的.中子能量为1~5MeV时,铁电存储器中没有发现单粒子翻转.中子能量为6~16MeV时,铁电存储器会发生单粒子翻转.当中子能量从6MeV增大到8MeV时,单粒子翻转截面从6×10^-16cm^2增大到6×10^-15cm^2,增大约1个数量级;当中子能量从8MeV增大到16MeV时,单粒子翻转截面从6×10^-15cm^2增大至1.8×10^-14cm^2,只增大到3倍左右.中子还会导致铁电存储器出现单粒子功能中断,其单粒子功能中断错误数随功能中断线性能量传递(linearenergytransfer,LET)阈值的增大呈指数形式减小.同时,铁电存储器的功能中断LET阈值越大,其单粒子功能中断错误截面受中子能量的影响越不明显.

The single event effect (SEE) of ferroelectric random access memory (FRAM) induced by high-flux neutrons in atmospheric radiation environments cannot be ignored.In this paper,Monte Carlo method is used to study the neutron SEE of FRAM.The total energy deposition caused by neutron incidence in the sensitive region of the ferroelectric memory increases with the increase of neutron energy,and the total energy deposition value inside the sensitive region is slightly larger than at the boundary.When the neutron energy is 1~5 MeV,no single event upset (SEU) is found in the ferroelectric memory.When the neutron energy is 6~16 MeV,the SEU occurs in the FRAM.When the neutron energy increasing from 6 MeV to 8 MeV,the SEU cross section of FRAM increasing from 6×10^-16 cm 2 to 6×10^-15 cm^2,which is about one order of magnitude increase;the neutron energy increasing from 8 MeV to 16 MeV,the SEU cross section of FRAM increasing from 6×10^-15 cm^2 to about 1.8×10^-15 cm^2,which is only increased by about 3 times.The neutron also causes a single event functional interrupt (SEFI) in the FRAM,and the error number of SEFI decreases exponentially with the increase of the linear energy transfer (LET) threshold.At the same time,the larger the function interruption LET threshold of FRAM,the less obvious the SEFI error cross section induced by neutron is affected by the neutron energy.