SEMICONDUCTOR MEMORY DEVICE INCLUDING 3-DIMENSIONAL MEMORY CELL ARRAY AND OPERATING METHOD THEREOF

摘要

According to an embodiment of the present invention, a method for operating a semiconductor memory device comprises the following steps of: setting channel regions of unselected cell strings; and reading data from selected memory cells of selected cell strings. The step of setting channel regions of the unselected cell strings comprises the following steps of: biasing an initial voltage to the channel regions of the unselected cell strings when a first pass voltage is applied to a plurality of word lines; floating the channel regions of the unselected cell strings; and increasing the first pass voltage to a second pass voltage during the floating.