| 摘要 |
<p>PROBLEM TO BE SOLVED: To prevent the occurence of erasing board disturb, writing drain disturb and writing gate disturb. SOLUTION: Nonvolatile memory cells are formed like a matrix on a plurality of wells 1A arranged in matrix, and the memory cells formed on the respective well 1A are connected with each other by a word line group 9X and a bit line group 10X crossing orthogonally the word line group 9X. In this case, the word line group 9X or bit line group 10X has such a hierarchical structure that it can control the voltage of word line or bit line independently every well 1A which is arranged in the direction of word line or bit line at the time when two or more wells 1A are arranged in the direction of word line or bit line.</p> |
