| 摘要 |
PURPOSE:To easily form a charge storing electrode having a cavity by utilizing uneveness on a semiconductor substrate surface, realize a large capacitance, and flatten the semiconductor substrate surface. CONSTITUTION:A first storage node 21 composed of a phosphorus-doped polysilicon film is deposited on a semiconductor substrate 1 on which an MOS transistor and bit lines are formed. A B2O3 film is deposited and flattened, and then the B2O3 film is formed in a recessed part by etching-back. A second storage node 22 composed of a phosphorus-doped polysilicon film is deposited, and a desired region is etched. After the B2O3 film is eliminated, a charge storing electrode having a cavity is obtained by etching a first storage node 21. A dielectric film 23 and a cell plate 24 composed of the phosphorus-doped silicon film are formed, thereby obtaining a memory cell. A large capacitance can be realized by forming a capacitor structure in a cavity part. |
