| 摘要 |
PURPOSE:To increase both of the integration density of an MOS-RAM memory cell and the accumulated capacitance by a method wherein an aperture the first insulation film has is filled with the first conductive film, further the second insulation film is formed by lamination so that at least part of the surface of the first conductive film may be exposed, thereafter the second conductive film if formed. CONSTITUTION:A thin oxide film 33 is formed on the surface of an Si substrate 30, and thereafter boron ions B<+> are implanted to the Si substrate 30 with a photo resist mask 34 as a mask, resulting in the formation of a p<+> layer 35. Next, the film 34 is removed after etching of the oxide film 33 with the film 34 as a mask, the polycrystalline Si 36 of the first layer doped with a high concentration n type impurity being deposited, and next an insulation film 38 of high dielectric constant being deposited on the polycrystalline Si. Then, the insulation film 38 and the Si 36 are etched by the method of plasma etching at the same time. Thereafter, the polycrystalline Si 39 of the second layer containing a high concentration n type impurity is deposited, and the pattern is formed by photo etching so as to cover the film 38. The oxide film 33 is removed, and a thin gate oxide film 40 is formed. |
