摘要
基于中国散裂中子源大气中子辐照谱仪提供的meV-GeV宽能谱中子束流,对128层电荷俘获型(charge trap,CT)3D NAND闪存开展中子辐照实验和仿真.研究发现,CT型3D NAND闪存在宽能谱中子辐照下的主要失效模式为单位翻转(single bit upset,SBU)、多单元翻转(multiple cell upset,MCU),其中SBU占比为82.6%.通过构建单粒子翻转(single event upset,SEU)事件的三维空间分布图发现,不同于重离子SEU的“串型”分布,中子SEU表现出显著的随机空间分布特点,仅存在少量“串型”分布的MCU事件.在MCU事件中,2位MCU占比最高,达到MCU事件的83.6%,高于2位的大尺寸MCU占比为16.4%,最大的MCU位数为7位.MCU图形以沿中子入射方向分布为主.进一步的中子输运仿真结果表明,中子在器件灵敏区内产生的二次粒子主要为N离子和Si离子.其中,线性能量传输(linear energy transfer,LET)小于10 MeV·cm^(2)·mg^(–1)的短射程二次粒子占主导,是诱发SBU的主要因素.少量LET值大、射程长的二次粒子是MCU的产生诱因.
In this work,an experimental study on the atmospheric neutron single-event effects in 128-layer charge trapping(CT)3D NAND flash memory is conducted by using the atmospheric neutron irradiation spectrometer(ANIS)at the China Spallation Neutron Source(CSNS).By integrating irradiation experiments,reverse analysis,and Monte Carlo neutron transport simulations,the influence of atmospheric neutron irradiation on the multiple-cell upset(MCU)susceptibility of CT 3D NAND flash memory is investigated and the underlying mechanisms,including the distribution of secondary particles within the sensitive volume and the characteristics of deposited charge are analyzed.The results indicate that under broad-spectrum neutron irradiation,the primary failure modes in CT 3D NAND flash memory are single-bit upsets(SBU)and MCU,with SBU accounting for 82.55%of the total events.By constructing a three-dimensional spatial distribution map of single-event upset(SEU),it is observed that compared with the dense“string-like”distribution formed by 78Kr ion irradiation(LET=11.4 MeV·cm^(2)·mg^(-1)),the spatial distribution resulting from neutron-induced SEU is much more random,with the former having only a small number of MCU showing a“string-like”pattern.Among the MCU events,2-bit MCUs are dominant,accounting for 83.6%of all MCUs,while larger sized MCUs(>2 bits)makes up 16.4%.The maximum observed MCU size is 7 bits.Furthermore,the spatial distribution of MCUs is primarily aligned along the direction of neutron incidence.By using the reverse analysis results,a device model is constructed,and Monte Carlo neutron transport simulations are performed.The simulation results reveal that secondary particles generated in the sensitive volume(SV)of the device by neutrons with energy E>1 MeV are predominantly silicon ions(37.98%)and nitrogen ions(27.95%).Since the SV material is nitride,the interaction between neutrons and the SV is mainly elastic scattering,during which secondary particles are produced.Among the secondary particles generated in the SV,most propagate along the direction of neutron incidence,while a small number of secondary particles in the central region produce oblique tracks.The majority of secondary particles generated in the SV have low LET values(<5 MeV·cm^(2)·mg^(-1))and short ranges(<100 nm),and these secondary particles are the primary cause of SBU.However,approximately 1.2%of the ions exhibit high linear energy transfer(LET)values(>10 MeV·cm^(2)·mg^(-1)),with the maximum LET value of secondary particles in the SV reaching 12.05 MeV·cm^(2)·mg^(-1).A small number of secondary particles with high LET values and long ranges are responsible for generating MCUs.
作者
李鸿德
张鸿
焦扬
雷志锋
杨炜坤
李惠
路国光
张战刚
LI Hongde;ZHANG Hong;JIAO Yang;LEI Zhifeng;YANG Weikun;LI Hui;LU Guoguang;ZHANG Zhangang(Institute of Physical Science and Information Technology,Anhui University,Hefei 230601,China;National Key Laboratory of Reliability Technology for Electronic Components,Fifth Institute of Electronics,Ministry of Industry and Information Technology,Guangzhou 511370,China;Institute of Modern Physics,Chinese Academy of Science,Lanzhou 730000,China)
出处
《物理学报》
北大核心
2026年第3期368-375,共8页
Acta Physica Sinica
基金
国家自然科学基金(批准号:12175045)
国家重点研发计划(批准号:2023YFF0616600)资助的课题。
