NONVOLATILE MEMORY DEVICE, OPERATING METHOD THEREOF AND MEMORY SYSTEM INCLUDING THE SAME

摘要

PURPOSE: A nonvolatile memory device, an operating method thereof and a memory system including the same are provided to have an improved operation speed by performing erasing in a sub block unit. CONSTITUTION: In a nonvolatile memory device, an operating method thereof and a memory system including the same, an erase voltage is applied to a substrate(111) during a first time. An erase voltage is delivered to the surface layer(114) of an NAND string. The word line erase prevention voltage is applied to word lines which are not selected during the first time. A second dummy word line voltage is applied to a dummy word line during the first time. A dummy word line is offered between first and second sub blocks. Electric field between selected sub word lines and an unselected word lines is suppressed. Data is red out from the selected sub block. Each sub block of the selected memory block is selectively refreshed.