CAPACITOR AND ITS MANUFACTURE

PURPOSE: To realize a semiconductor device with a sufficient capacity of a capacitor by sufficiently increasing a surface area by forming deep irregularities in a storage electrode to such an extent that the bottom of a first conductive layer is not exposed. CONSTITUTION: A nonconductive layer 22 is evaporated onto a lower substrate 21, which is a first conductivity layer of a capacitor. Polysilicon 23 is deposited at 540-600 deg.C with irregularities and is etched back to form a polysilicon islands 24. The nonconductive layer 22 is etched using the islands 24 as a mask. The lower substrate 21 is etched to a constant depth, using the remaining polysilicon islands 24 and the nonconductive layer 22. The rest of the nonconductive layer 22 is removed, and the lower substrate 21 is patterned to form deep irregularities on its surface. The first conductivity layer 21 of the capacitor is coated with a capacitor dielectric film 25, and a second conductive film 26 of the capacitor is formed. The surface area is increased in this way, and a sufficiently charge- storing capacity can be assured.