| 摘要 |
PURPOSE:To decrease the leak current of a capacitor electrode, increase junction breakdown strength, and prevent malfunctions, by constituting an impurity region serving as a capacitor electrode and a guard ring of high impurity concentration so as not to be in direct contact with each other. CONSTITUTION:The surface of a P-type silicon substrate 1 is divided by an element isolation region composed of an oxide film 3 filling grooves, and channel stoppers 2. On the surface, a memory cell composed of a capacitor and a memory transistor is formed. The capacitor is constituted in the manner in which an n-type impurity region 6 is made one electrode, and thereon the other electrode 8 is arranged via a dielectric film 4a. The memory transistor is constituted in the manner in which a drain 7 of n<+> type high concentration is connected to an Al electrode 12 and a gate 10 is formed on a p-type impurity region 6 via a gate insulating film 4b. A guard ring 2 of p<+> type high concentration and the n-type impurity region 5 are not in direct contact with each other. |
