AEP-LDPC ECC with Error Dispersion Coding for Burst Error Reduction of 2D and 3D NAND Flash Memories

To improve the reliability of Triple-Level Cell (TLC) NAND flash memory, Advanced Error Prediction (AEP) low-density parity-check (LDPC) ECC with Error Dispersion Coding is proposed. In the conventional LDPC, error-correction capability is degraded due to burst errors [1]. To reduce burst errors and improve the error-correction capabilities of LDPC, this paper proposes Error Dispersion Coding (EDC) which reduces burst errors, decreases the worst bit-error rate (BER) of Upper/Middle/Lower pages, and finally extends the data-retention time of TLC NAND flash memory. By applying proposed EDC, in 3D-TLC NAND flash memory, the burst errors and the worst BER are decreased by 87% and 40%, respectively. As a result, the acceptable data-retention time is extended by 1.8 and 2.6 times in 2D and 3D-TLC NAND flash memory, respectively.