| 摘要 |
PURPOSE:To increase a surface area of a charge storage electrode by a method wherein a side wall formed on the lateral wall of a groove provided in a semiconductor substrate is used as the charge storage electrode of a memory capacitor and an interlayer insulation film is made thick. CONSTITUTION:An interlayer insulation film 107 is deposited on MOSFET on a P-type silicon substrate 101, an opening region is formed in the film 107 so that the surface of a drain diffused layer 105 is exposed, and in this opening region, a groove is provided in a self-alignment manner in the substrate. Then, a conductive polysilicon film 111 is deposited and a side wall film of the polysilicon layer 111 is formed in the opening region and on the inner wall of the groove. Subsequently, a capacity insulation film 113 and a cell plate electrode 114 are formed and this side wall is used as a charge storage electrode. According to this constitution, the surface area of the charge storage electrode can be increased by making the interlayer insulation film thick. |
