| 摘要 |
PURPOSE:To improve flatness, by filling a groove with an N<+>-type polysilicon conducting layer consisting of at least two or more polysilicon layers while interposing an insulating film between these polysilicon layers. CONSTITUTION:A capacity consisting of a dielectric film 8, an N<+>-type polysilicon conducting layer 18, an insulating film 19 and a polysilicon conducting layer 20 is formed on a groove formed in an Si substrate 1 having an epitaxial layer 3. A field SiO2 layer 4 comprises oxide films of the N<+>-type polysilicon conducting layer 18 and the polysilicon conducting layer 20, so that it serves as an insulating/isolating film for isolating the capacity electrode from a word line 11B of an adjacent cell. Since the N<+>-type polysilicon conducting layer 18 and the polysilicon conducting layer 20 are isolated from the word line 11B of the adjacent cell by the thick field SiO2 film 4, a memory cell thus obtained is allowed to have sufficiently high dielectric strength and the word line capacity can he decreased. Any allowance is not needed for working the N<+> polysilicon conducting layer 14 or for registering it with the connecting section, and this fact enables the memory cell to be constructed finely. In this manner, the flatness is improved while the memory cell can be constructed finely. |
