US Patent 7800944 Nonvolatile semiconductor memory device and programming method thereof

Disclosed is a nonvolatile memory device and programming method of a nonvolatile memory device. The programming method of the nonvolatile memory device includes conducting a first programming operation for a memory cell, retrieving original data from the memory cell after the first programming operation, and conducting a second programming operation with reference to the original data and a second verifying voltage higher than a first verifying voltage of the first programming operation.