NONVOLATILE MEMORY DEVICE AND PROGRAM VERIFY METHOD THEREOF

A program verify method of the nonvolatile memory device includes supplying a first program verify voltage to a word line coupled to memory cells of a memory cell array, sensing a voltage of a bit line coupled to the memory cells in response to a first sense signal, supplying a second program verify voltage higher than the first program verify voltage to the word line, and sensing a voltage of the bit line in response to a second sense signal having a lower voltage level than the first sense signal.