Memory device with improved threshold voltage distribution and operating method thereof

Abstract

Provided is a memory device with improved threshold voltage distribution and an operating method of the memory device. The memory device includes a memory cell array including a plurality of memory cells, a voltage generator configured to generate a program voltage and a verification voltage applied to the plurality of memory cells during a data write operation, and a control logic configured to control multiple program loops to program the memory cells to multiple program states during the data write operation and configured to determine whether programming passes or fails in the multiple program loops, wherein the control logic controls the program loops to verify one or more (n+1)-th memory cells to be programmed to an (n+1)-th program state by using a verify condition for verifying an n-th program state in at least one of the multiple program loops (n is an integer greater than or equal to 1).