| 摘要 |
PURPOSE:To perform writing by a low voltage, by making the band width of an insulating film interposed between a first electrode to inject electrons and a second electrode into which electrons are injected wide and narrow, on the first electrode side and on the second electrode side, respectively. CONSTITUTION:The band width of a writing gate insulating film 4 between a writing gate electrode 3 injecting electrons at the time of writing information and a storage gate electrode 7 into which electrons are injected is made wide and narrow, on the writing gate electrode 3 side and on the storage gate electrode 7 side, respectively. Therefor, electron is easily injected form the writing gate electrode 3 to the storage gate electrode 7, and electron is difficult to be injected in the inverse direction. Similarly, the band width of an erasing gate insulating film 6 between the storage gate electrode 7 injecting electrons at the time of erasing information and an erasing gate electrode 5 into which electrons are injected is also made wide and narrow, on the storage gate electrode 7 side and on the erasing gate electrode 5 side, respectively. |
