| 摘要 |
PROBLEM TO BE SOLVED: To enable high integration of a semiconductor element by a method, wherein a storage electrode, having an increased surface area by forming irregularities on a sidewall, is formed using differences in the etching selectivity ratio between an impurity-doped silicon layer and a non-impurity doped silicon layer, and then a dielectric film and a plate electrode are formed. SOLUTION: An oxide film 21' is removed using the difference in the etching selectivity ratios between amorphous silicon films 17, 19, 25 and 27 and the oxide film 21'. Then, the entire body is annealed, and impurities contained in the amorphous silicon films 17 and 27 are activated. Next, the impurity-doped polycrystalline films 17 and 27 are etched in a specific width using the difference in etching selectively ratios, and an irregular surface is formed on the sidewall of a cylindrical structure. Then, the impurities contained in the polycrystalline silicon films 17 and 27 are diffused and doped on the polycrystalline silicon films 19 and 25 by performing a heat treatment process, and a silicon storage electrode, having increased surface area, is formed. A dielectric film and a plate electrode are formed on the surface of the storage electrode by the processes which are to be performed later. |
