摘要 |
PURPOSE:To write and eliminate electrically easily by a method wherein a control gate electrode faces a semiconductor substrate with a gate insulating film in between. CONSTITUTION:A field insulation film 22 is formed on a p type silicon substrate 21 and a memory element is composed of a gate insulating film 23, a control gate electrode 24 of polycrystalline silicon, an insulating film 25, a floating gate electrode 26 of polycrystalline silicon, an n<+> type source region 27 and an n<+> type drain region 28. Then a phosphorus silicic acid glass film 29 and aluminum electrodes 30, 31 are formed. Above formation is made in such a manner that a part of the floating gate electrode 26 overlaps the control electrode and the rest part of the floating gate electrode 26 overlaps the substrate with an insulating film in between. With above method injection of an electric charge into the floating gate electrode becomes easy, so that electrical writing and eliminating becomes very easy. |