Effects of abnormal cell-to-cell interference on p-type floating gate and control gate NAND flash memory

Abstract

Abnormal cell-to-cell interference occurring in NAND flash memory has been investigated. In the case of extremely downscaled NAND flash memory, cell-to-cell interference increases abnormally. The abnormal cell-to-cell interference has been observed in a p-type floating gate (FG)/control gate (CG) cells for the first time. It has been found that the depletion region variation leads to the abnormal cell-to-cell interference. The depletion region variation of FG and CG is determined by state of neighbor cells. The depletion region variation affects CG-to-FG coupling capacitance and threshold voltage variation (Delta V-T). Finally, it is observed that there is a symmetrical relationship between n- and p-type FG/CG NAND flash memory in terms of cell-to-cell interference. (C) 2014 The Japan Society of Applied Physics