基于高海拔地区的大气中子单粒子效应实时测量试验研究

开展65 nm高速大容量静态随机存取存储器（SRAM）大气中子单粒子效应特性及试验评价技术研究，基于4 300 m高海拔地区大面积器件阵列实时测量试验，突破效应甄别、智能远程测控等关键技术，在153 d的试验时间内共观测到错误43次，其中器件内单粒子翻转39次，多单元翻转（MCU）在单粒子翻转中占比23%，最大的MCU为9位。对高能中子、热中子和封装α粒子的贡献比例进行了分析，并基于多地中子通量数据，推演得到北京地面和10 km高空应用时的单位翻转（SBU）和MCU失效率（FIT）。发现地面处软错误的主要诱因为封装α粒子，随着海拔的增高，大气中子对软错误的贡献比例明显增大；MCU全部由高能中子引起，北京10 km高空处的MCU FIT值明显增大，其占比由地面的8%增大至26%。结合器件版图布局，对MCU产生机理进行了深入分析。最后，提出一种目标导向的存储器软错误加固策略优化方法。

Experimental Study on Real-time Measurement of Atmospheric-neutron Induced Single Event Effect Based on High-altitude Area

Based on the test site at the Qinghai?Tibet Plateau with an altitude of 4 300 m, atmospheric neutron single event effects of a 65 nm high?speed large?area static random access memory (SRAM) array were measured in real?time. By breaking through key technologies such as effect screening, intelligent remote measurement and control, a total of 39 single?event upset were observed during the 153 d test period, of which multiple?cell upset (MCU) accounts for 23%, and the largest MCU is 9 bits. The contribution ratios of high?energy neutron, thermal neutron and alpha particle were analyzed in detail, and based on the multi?ground neutron flux data, the single?bit upset (SBU) and MCU failure in time (FIT) at Beijing ground and 10 km high?altitude application were deduced. It is found that the main cause of soft error on the ground is the alpha particle. As the altitude increases, the contribution of atmospheric neutron to soft error increases significantly. All MCUs are caused by high?energy neutron, and the MCU FIT value at an altitude of 10 km in Beijing is obviously increased. Its proportion increases from 8% of the ground to 26%. In combination with the device layout, an in?depth analysis of the MCU generation mechanism was carried out. Finally, a goal?oriented optimization method of memory soft error hardening strategy was proposed.