Spread programming for NAND flash

The aggressive scaling of NAND flash memories has caused significant degradation in their reliability and endurance. One of the dominant factors in this degradation is the inter-cell-interference (ICI), by which the programming of a cell can affect near-by neighboring cells corrupting the information that they store. This paper proposes a new data representation scheme which increases endurance and significantly reduces the probability of error caused by ICI. The method is based on using an orthogonal code to spread each bit across multiple cells, resulting in a more uniform distribution of voltages being programmed in the cells.