| 摘要 |
<p>PROBLEM TO BE SOLVED: To realize high reliability, low-voltage rewriting and low-voltage reading of a nonvolatile semiconductor storage device provided with a floating gate electrode and a control gate electrode. SOLUTION: A memory transistor and a select transistor are formed side by side between the source diffusion layer 8 and drain diffusion layer 9 of a semiconductor substrate 1 with an intermediate diffusion layer 10 interposed. The memory transistor consists of a gate insulation film 4, a floating gate electrode 5, an inter-electrode insulation film 6, and a control gate electrode 7 in which a tunnel current is allowed to flow, and the select transistor is provided with a gate insulation film 11 and a selection gate electrode 13. When an electron is removed and injected from the floating gate electrode 5, a tunnel current whose electron passes on the almost entire surface of the gate insulation film 4 under the floating gate electrode 5 is used so as to realize high reliability and low-voltage rewriting. Further, the device is provided with the select transistor, so that low-voltage reading can be realized.</p> |
