针对核设施机电设备中控制系统存储单元耐辐射可靠性评价的需要, 以国产NOR型Flash存储器为研究对象, 对器件存储阵列浮栅单元的总剂量损伤阈值开展了实验研究。综合利用SMOTE算法和Bootstrap法建立了一种基于极小子样的器件耐辐照可靠性评价方法, 对被测样品校验失效剂量进行了统计分析。实验结果表明, 器件浮栅单元的主要失效模式为浮栅电荷损失造成的阈值电压降低, 平均校验错误剂量为(631.89±103.64)Gy(Si)。统计分析表明, 器件总剂量损伤阈值服从对数正态分布。基于SMOTE-Bootstrap的可靠性评价方法避免了传统Bootstrap再生样本过于集中的问题, 可应用于极小子样的可靠性评价。

For the need of radiation reliability analysis on the memory devices which were applied in the nuclear facilities, the threshold dose of the floating gate cells in a domestic NOR-type flash memory had been investigated. A reliability analysis method with extremely small sample size had been established by utilizing the SMOTE-Bootstrap algorithm. The experimental results showed that the dominant failure mode of the floating gate cell was the threshold voltage reduction due to charge loss in the floating gate, and the average verification error dose was 631.89±103.64)Gy(Si). The statistical analysis results showed that the radiation damage dose of the device obeyed the lognormal distribution. The SMOTE-Bootstrap algorithm avoided the problem that the conventional bootstrap method would cause an abnormal data concentration in the generated samples. Meanwhile, the algorithm had been proved to be suitable for the application of reliability analysis with extremely small sample size.