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Published April 2016 | public
Book Section - Chapter

Error Characterization and Mitigation for 16nm MLC NAND Flash Memory under Total Ionizing Dose Effect

Abstract

This paper studies the system-level reliability of 16nm MLC NAND flash memories under total ionizing dose (TID) effect. Errors that occur in the parts under TID effect are characterized at multiple levels. Results show that faithful data recovery only lasts until 9k rad. Data errors observed in irradiated flash samples are strongly asymmetric. To improve the reliability of the parts, we study error mitigation methods that consider the specific properties of TID errors. First, we implement a novel data representation scheme that stores data using the relative order of cell voltages. The representation is more robust against uniform asymmetric threshold voltage shift of floating gates. Experimental results show that the scheme reduces errors at least by 50% for blocks with less than 3k program/erase cycles and 10k rad. Second, we conduct empirical evaluations of memory scrubbing schemes. Based on the results, we identify a scheme that refreshes cells without doing block erasure. Evaluation results show that parts under this scrubbing scheme survive up to 8k PECs and 57k rad total doses.

Additional Information

© 2016 IEEE. Date Added to IEEE Xplore: 26 September 2016. Part of the research was carried out at the Jet Propulsion Laboratory, California Institute of Technology, under a contract with the National Aeronautics and Space Administration.

Additional details

Created:
August 20, 2023
Modified:
October 20, 2023