| 摘要 |
PURPOSE:To obtain a capacitor structure which can be applied to a high density DRAM cell by composing a storage electrode of a first protrusion and a second protrusion surrounding the first protrusion. CONSTITUTION:A silicon oxide film 38 is removed, an NO film is formed as a capacitor insulating film 40 by forming and nitriding a silicon oxide thin film, and an upper capacitor electrode 41 is formed of phosphorus-or arsenic- doped polycrystalline silicon film by a CVD. A lower capacitor electrode is composed of polycrystalline silicon sidewalls 35, 39 and polycrystalline silicon film 32. Accordingly, a lower capacitor formed of the sidewall 35, the sidewall 39 surrounding the sidewall 35 and the film 32 supporting them is connected to an n-type region 18. Since a bit line is shared for one element region to provide two cells, both sides of the element region are formed in a similar structure. Such a lower capacitor is extended not only to own memory cell region but to adjacent memory cell region to form a capacitor having a large capacity. |
