Characterization of Inter-Cell Interference in 3D NAND Flash Memory

Abstract

We characterize inter-cell interference in commercial three-dimensional NAND flash memory. By writing random data into 3D NAND and collecting sample means and sample variances of cell values corresponding to a particular set of input values in fixed relative neighboring cell locations, it is shown that the interference coming from any target cell locations can be measured. We observe that four neighboring cells, two along the same pipe and two along the same bit line, are responsible for most of the interference exerted on a given victim cell. Contrary to the general belief, the total amount of interference is found to be fairly significant even in 3D NAND; if compensated properly, the number of errors can be reduced significantly.