| 摘要 |
PURPOSE:To prevent a memory cell from being formed into depression and to constitute a memory array only of the memory cell, by connecting an individual pump circuit to every bit line via a high voltage switching circuit respectively, and connecting the drain side of a non-volatile memory transistor source- grounded to each bit line. CONSTITUTION:The pump circuits 1a-1c are connected to bit lines (a-c) via the high voltage switching circuits 2a-2c. And a word line 4 is connected to the drain and the gate of floating gate type non-volatile memory transistors 5a-5c respectively. Consequently, when an electron is drawn and the threshold values of the memory cells 5a-5c are decreased, a channel current flows from the drain to the source, and the high voltages of the bit lines (a-c) are decreased, and no more drawing of the electrons from the memory cells 5a-5c occurs. In such a way, it is possible to easily prevent the memory cell from being formed into the depression automatically, and to constitute the cell only of one memory cell transistor. |
