| 摘要 |
<p>PURPOSE:To obtain sufficiently large read margin with small write margin by simultaneously executing implantation of electron to one floating gate and release of electrons from the other floating gate. CONSTITUTION:Two pairs of floating gates 14, 15, electrodes 16, 17 which are capacitively coupled thereto and electrodes 18, 19 which send and receive the electrons through the gates 14, 15 and tunnel oxide films 20, 21 are provided. The electrode 16 and electrode 18 are connected in common. The electrode 17 and electrode 19 are also connected in common. The two pairs of electrode connected in common are connected to the program bus lines 34, 35 through the transistors 24, 25. Implantation and release of charges are alternately carried out in the reverse directions to the gates 14, 15. Thereby, sufficiently large read margin can be obtained with small write margin.</p> |
