Investigation of Inhibited Channel Potential of 3D NAND Flash Memory According to Word-Line Location

Natural local self-boosting (NLSB) was analyzed according to the location of a selected word-line (WL) where potential boosting occurs. When the same pattern occurred, it was found that the top cells (WL11 through WL15) and bottom cells (WL0 through WL4) have identically symmetrical potential boosting. In addition, in the region of the middle cells (WL6 through WL10), a slight change in the potential boosting was also almost the same. In the 3D NAND, where there was a dummy WL (DWL), the NLSB for the edge WL changed as the pattern of the DWL changed. The DWL did not affect the NLSB of the main cell, regardless of the pattern. Therefore, the high potential of the edge WL could reduce the potential difference between the main cell and the edge WL using the DWL.