| 摘要 |
PURPOSE:To hold the degree of insulation between polycrystalline silicon layers and improve the accuracy of positioning by a method wherein an oxide layer is formed on the polycrystalline silicon layer and a silicon nitride layer on the oxide layer, and an oxide film with sufficient thickness is made up to the flank of the silicon layer. CONSTITUTION:The field oxide film 14 and a capacitor oxide film 18 are coated with the first polycrystalline silicon layer 17, an oxide film 19 is formed on the layer 17 by means of high temperature treatment, and the upper surface is further coated with a silicon nitride film 13. The nitride film 13 is etched according to a pattern, and only a power source line electrode layer and a capacitor electrode region are left. Each film and the polycrystalline silicon layer 17 are sufficiently etched so as to over-etch the layer 17. A side etched part is treated at a high temperature, and an oxide film with sufficient thickness is made up. The nitride film 13 functioning as a mask is removed, all oxide films in a gate region are removed, a gate oxide film 20 is formed, and the second polycrystalline silicon layer 15 is wired on the upper surface. Thus, the accuracy of a memory-cell can be improved. |
