重离子辐照带有ECC的65nm SRAM器件“伪多位翻转”特性研究

Radiation-Induced “Fake MBU” by Heavy Ion in 65 nm SRAM with ECC

为了提高纠错编码(ECC)的有效性,先进的静态随机存储器(SRAM)多采用位交错结构。但是,在没有物理版图信息的情况下,位交错设计使得从辐照测试数据中提取出多单元翻转(MCU)变得更加困难。运用Bi离子辐照带有ECC的65 nm SRAM器件,研究了该款器件在重离子辐照下的敏感性。为"伪多位翻转(FMBU)"以及MCU的数据分析提供了理论指导和帮助,完善了判别MCU的基本法则。除此之外,研究结果表明,ECC的汉明编码对于纳米器件的效果不够理想。在未来的空间应用中,需考虑更高层次的编码算法来抵抗单粒子翻转。

In order to improve the robustness of error-correcting codes（ECC）, modern static random access memory（SRAM） always use bit-interleaving structure. However, in the absence of physical layout information,the bit-interleaving design makes it more difficult to extract the multiple-cell upset（MCU） from the test data. In this paper, the sensitivity of Bi ion irradiation was investigated in a 65 nm technology SRAM with ECC. The experimental results provide a theoretical guidance and help for the fake multiple-bit upset（FMBU） and MCU data analyzing, which improve and perfect the basic rules extracting MCU from the test data. In addition, the results show that the performance of hamming encoding is not ideal in Nano scale SRAM. In the future of space applications, it is necessary to consider more advanced algorithms to against SEU.