Verification of SEU resistance in 65 nm high-performance SRAM with dual DICE interleaving and EDAC mitigation strategies

• Published in: Nuclear science and techniques Vol. 32; no. 12; pp. 64 - 76
• Main Authors: He, Ze, Zhao, Shi-Wei, Liu, Tian-Qi, Cai, Chang, Yan, Xiao-Yu, Gao, Shuai, Liu, Yu-Zhu, Liu, Jie
• Format: Journal Article
• Language: English
• Published: Singapore Springer Singapore 01.12.2021; School of Nuclear Science and Technology,University of Chinese Academy of Sciences,Beijing 100049,China%Department of Computer Science and Technology,Tsinghua University,Beijing 100084,China; Institute of Modern Physics,Chinese Academy of Sciences,Lanzhou 730000,China
• Subjects: Beam Physics; Nuclear Energy; Particle Acceleration and Detection; Particle and Nuclear Physics; Physics; Physics and Astronomy; Heavy ion; Static random-access memory (SRAM); Error detection and correction (EDAC) code; Single event upset (SEU); Radiation hardening technology; Double interlocked storage cell (DICE); Single event upset(SEU); Static random-access memory(SRAM); Double interlocked storage cell(DICE); Error detection and correction(EDAC)code
• ISSN: 1001-8042; 2210-3147
• DOI: 10.1007/s41365-021-00979-8

A dual double interlocked storage cell (DICE) interleaving layout static random-access memory (SRAM) is designed and manufactured based on 65 nm bulk complementary metal oxide semiconductor technology. The single event upset (SEU) cross sections of this memory are obtained via heavy ion irradiation with a linear energy transfer ( LET ) value ranging from 1.7 to 83.4 MeV/(mg/cm 2 ). Experimental results show that the upset threshold ( LET th ) of a 4 KB block is approximately 6 MeV/(mg/cm 2 ), which is much better than that of a standard unhardened SRAM with an identical technology node. A 1 KB block has a higher LET th of 25 MeV/(mg/cm 2 ) owing to the use of the error detection and correction (EDAC) code. For a Ta ion irradiation test with the highest LET value (83.4 MeV/(mg/cm 2 )), the benefit of the EDAC code is reduced significantly because the multi-bit upset proportion in the SEU is increased remarkably. Compared with normal incident ions, the memory exhibits a higher SEU sensitivity in the tilt angle irradiation test. Moreover, the SEU cross section indicates a significant dependence on the data pattern. When comprehensively considering HSPICE simulation results and the sensitive area distributions of the DICE cell, it is shown that the data pattern dependence is primarily associated with the arrangement of sensitive transistor pairs in the layout. Finally, some suggestions are provided to further improve the radiation resistance of the memory. By implementing a particular design at the layout level, the SEU tolerance of the memory is improved significantly at a low area cost. Therefore, the designed 65 nm SRAM is suitable for electronic systems operating in serious radiation environments.