To embody a method of manufacturing a kind of tubular stacked capacitor which resolves the leakage problem of the capacitor by forming a silicon oxide nitride mask and readily flattening the top surface of the lower polysilicon electrode of the capacitor.

A dielectric oxide layer 2 and a silicon nitride layer 3 are deposited on a semiconductor substrate 1 including electric devices, and one contact is formed in the silicon nitride 3 and dielectric oxide layer 2 and filled with a first polysilicon layer 4a, and an oxide layer and a silicon oxide nitride layer are then deposited. Furthermore, the photoresist pattern of the lower polysilicon electrode 4c of the capacitor is defined. The silicon oxide nitride layer and the oxide layer are etched, and the oxide layer is side-etched thereafter, and a second polysilicon layer 4b is deposited, and the second polysilicon layer 4b and the first polysilicon layer 4a are etched furthermore to form the structure of the lower plysilicon electrode 4c of the capacitor. After the silicon oxide nitride layer, the oxide layer and a part of the silicon nitride layer are removed, the insulation layer and the upper polysilicon electrode structure of the capacitor.