STACK CAPACITOR FORMATION OF SEMICONDUCTOR ELEMENT

PURPOSE: To improve the storage ability of a semiconductor by flattening a polysilicon layer for a charge-storing electrode in particular and then forming a groove to increase the capacitance of a capacitor, so as to increase the capacity of the capacitor by the effective area of the limited capacitor. CONSTITUTION: First and second oxidized films 8 and 10 are formed at the upper part of an overall structure and a first polysilicon layer 11 for a charge- storing electrode is vapor-deposited to its upper part to be flattened. The layer 11 is partially etched to a degree not exposing the film 10. A third oxidized film 12, exposed for forming a groove 18 at the layer 11 and the layer 11, are successively etched. A spacer 14a is formed at both sidewalls of the films 11 and 12 and the inner sidewall of the groove 18. A dielectric film 15 is formed on the surface of a charge-storing electrode 19 formed from the layer 11 and the spacer 14a to form a plate-electrode 20 at the upper part of the overall structure. Thereby, the capacitance of capacitor is increased.