Describes the novel technologies of poly-Si and Si/sub 3/N/sub 4/ film which are used for the storage capacitor electrode and also dielectric film of a DRAM STC (stacked capacitor cell), respectively. Poly-Si film deposited at about 570 degrees C has a rugged surface. It is found that 0.1 mu m poly-Si film deposited at 570 degrees C has a 2.5-times-larger surface area than film deposited at 620 degrees C. It is also found that Si/sub 3/N/sub 4/ film deposited at 600 degrees C has a higher oxidation resistance than film deposited at 750 degrees C. By the use of the rugged surface poly-Si film and the 6.3 nm SiO/sub 2/-equivalent-thick Si/sub 3/N/sub 4/ film, an STC which has a storage capacitance equal to that of the conventional STC cell with 2.5 nm SiO/sub 2/-equivalent-thick dielectric film can be realized.<<ETX>>