| 摘要 |
PURPOSE:To improve TDDB characteristics, and to contrive improvement in long-term reliability by a method wherein the edge part, having a steeply-formed recess part, is smoothed by providing an oxide film or a polysilicon film on a rug-surfaced storage electrode. CONSTITUTION:A field oxide film 2, a gate electrode and the like are formed on a silicon substrate 1, a source and drain 4 are formed by diffusion, an aperture is formed on a cell contact 5a, and a storage electrode 6 is formed. The surface of the storage electrode 6 is oxidized in the thickness of 200 to 300Angstrom at the high temperature of 950 to 1050 deg.C with the ratio of oxygen and nitrogen of 0.1 or lower. Then, the oxide film is removed by hydrogen fluoride, and the recessed part is smoothed. Subsequently, impurities are diffused, conductivity is given and a capacitor insulating film, a cell-plate electrode, an intermediate insulating film, and a wiring etc. are formed. As a result, edge parts are smoothed, the generation of deterioration from the edge parts is prevented, and the improvement in long-term reliability can be achieved. |
