| 摘要 |
<p><P>PROBLEM TO BE SOLVED: To provide a semiconductor storage device which is enabled to be erased by sector. <P>SOLUTION: Wordlines in a cell array 2 are classified in every 8 lines, and erasure sectors ES0-ES15 are constituted in each block. A memory cell belonging to an erasure sector being an erasure object is made to perform an erasure operation and a memory cell belonging to an erasure sector being other than the erasure object is not made to perform the erasure operation by applying prescribed positive voltage to 8 wordlines belonging to an erasure sector being a erasure object in a status applying prescribed negative voltage to a silicon substrate, and also grounding the wordlines belonging to the erasure sector being other than the erasure sector. Therefore, sector erasure in the unit of the above erasure sector is realized. In the cell array 2, the memory cells are arranged in the state of a 2-dimensional matrix. The memory cell has a pair of floating gates and the data of 2 bits or more can be rewritably held. <P>COPYRIGHT: (C)2006,JPO&NCIPI</p> |
