| 摘要 |
PURPOSE:To enable the roughened surface of a polysilicon film to be restrained from being deformed and decreasing in area by a method wherein the roughened polysilicon film serving as a storage electrode is formed, a protective film is formed thereon, and then impurity ions are implanted. CONSTITUTION:A cell contact 2 is provided to an insulating film 9 formed on a substrate 1. In succession, a polysilicon lower film 3 serving as the lower layer of a storage electrode is formed on all the surface of the cell contact 2 including its side faces, a polysilicon upper film 4 is forroed thereon, and the surface of the upper film 4 is roughened under prescribecl conditions. Then, a protective film 5 is formed, and then N-type impurity ions are implanted into the polysilicon films 3 and 4. The protective film 5 is removed, and the polysilicon films 3 and 4 are patterned into a storage electrode 6. In succession, a capacitor insulating film 7 and a cell plate electrode 8 are formed to constitute a capacitor. By this setup, the roughened surface of a polysilicon film can be stopped from being deformed and kept unchanged in increase of area. |
