NONVOLATILE MEMORY DEVICE AND PROGRAM OPERATION METHOD THEREOF

摘要

The present invention relates to a nonvolatile memory device and an operating method thereof. The method for operating the nonvolatile memory device which includes a cell string which is vertically formed on a substrate and selects memory cells with a string selection line unit according to the embodiment of the present invention comprises the steps of: determining an order to program the selected page among pages which share the same word line; determining the level of a voltage which is supplied to the selected page according to the order to program the selected page; and writing data on the selected page by using a voltage with the determined voltage level. A reading failure is prevented due to the reduction of a reading margin by the operation method according to the embodiment of the present invention.