摘要 |
A nonvolatile semiconductor memory device comprises, an internal memory cell array formed in internal area of a surface of semiconductor substrate, a row decoder and a column decoder formed in the internal area to select memory cell of the internal memory cell array, a peripheral circuit formed in the internal area to write and read a selected memory cell in the memory cell array, and external memory cell array formed in external area of the surface of the semiconductor substrate arranged beside the internal memory cell array and electrically separated from the internal memory cell array. |