| 摘要 |
PURPOSE:To achieve a programmable ROM in which electric erase of data is obtainable, by changing a voltage given to the erase gate of a memory cell and measuring amount of charge stored to a floating gate. CONSTITUTION:A region ABCD indicates a memory cell for one bit's share of this semiconductor storage device. This memory cell consists of a MOS transistor, in which a conductor layer 15 of the 2nd layer is made of a floating gate, conductor layer 18 of the 3rd layer is of a control gate, conductor layer 14 of the 1st layer is of erase gate, N<+> type semiconductor layer 19A is taken as the drain and N<+> type semiconductor layer 19C is taken as the source. |
