NONVOLATILE MEMORY DEVICE FOR CONTROLLING SLOPE OF WORD LINE VOLTAGE AND ITS PROGRAM METHOD

PROBLEM TO BE SOLVED: To provide a nonvolatile memory device and its program method. SOLUTION: The nonvolatile memory device includes a nonvolatile memory cell array including a plurality of nonvolatile memory cells connected to a plurality of word lines, and a word line voltage generator for generating first and second sequences of voltage pulses. The nonvolatile memory device applies one of the first and second sequences of voltage pulses to a selected one of word lines to program the nonvolatile memory cells connected to the selected word line. A slope of at least one voltage pulse of the first sequence of voltage pulses is greater than a slope of at least one voltage pulse of the second sequence of voltage pulses. In general, the first sequence of voltage pulses is applied to word lines far away from the string select line (SSL), and the second sequence of voltage pulses is applied to word lines that are close to the SSL. COPYRIGHT: (C)2007,JPO&INPIT