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We have successfully fabricated and characterized sub-30 nm and sub-20 nm BE-SONOS NAND flash. Good device characteristics are achieved through two innovative processes: (1) a low-energy tilt-angle STI pocket implantation to suppress the STI corner edge effect, and (2) a drain offset using an additional oxide liner to improve the short-channel effect. The conventional self-boosting program-inhibit and ISPP (incremental step pulse programming) for MLC storage are demonstrated for 20 nm BE-SONOS NAND operation. Read current stability and read disturb life time are also evaluated. The estimated number of storage electrons is only 50-100, and for the first time we have demonstrated successful data retention after 150degC baking in the ldquofew-electronrdquo regime. Our results strongly suggest that BE-SONOS is a promising charge-trapping (CT) technology for NAND Flash scaling.