Multi-bit nonvolatile memory device and related programming method

A method of programming a nonvolatile memory device comprising a plurality of n-valued nonvolatile memory cells arranged in a matrix and further arranged in a plurality of strings, wherein n is a natural number greater than or equal to two (2), the method comprising:

• defining odd and even strings among the plurality of strings and identifying a particular odd string and a corresponding particular even string among the odd and even strings;
• programming i-valued data to first and second groups of three or more contiguous memory cells within the particular odd and even strings, respectively, before programming (i+1)-valued data to any memory cells in the first odd and even strings;
• after programming i-valued data to the first and second groups of three or more contiguous memory cells, programming (i+1)-valued data to a particular memory cell among the first and second groups of three or more contiguous memory cells.

A nonvolatile memory device, comprising:

• a memory array including a plurality of n-valued memory cells arranged in a matrix, where n is a natural number greater than or equal to two (2);
• wherein a group of three or more memory cells contiguously arranged along a first direction in the matrix are programmed with i-valued data (i<n) during three or more respectively distinct program periods, before any of the three or more memory cells is programmed with (i+1)-valued data, and then after all of the three or more memory cells are programmed with the i-valued data, a particular memory cell among the three or more memory cells is programmed with (i+1)-valued data.