| 摘要 |
PURPOSE:To provide an oxidation-resistant film near the upper edge part of a capacitor trench so as to have a capacitor electrode and a capacitor oxide film separated from each other. CONSTITUTION:An N<+>-type impurity layer 14 which is the one side capacitor electrode is formed on the surface of a P-type silicon substrate 11 in a trench 13 formed in the substrate 11 and a capacitor oxide film 16 is formed on the inner wall of the impurity layer 14. The trench 13 is filled with a polycrystalline silicon film 17 which is the other side capacitor electrode. A silicon nitride film 27 which is oxidation-resistant is formed on the surface of the polycrystalline silicon film 17 and near the upper edge part 13a of the trench 13 and the rest of the part of the polycrystalline silicon film 17 is covered with a silicon oxide film 25. A gate electrode 20 is formed on the substrate 11 and near the upper edge part 13a of the trench 13 with a gate oxide film 21 therebetween. An N<+>-type impurity layer 18 which is a drain region is formed and an aluminum wiring (bit line) 24 which is formed on an interlayer insulating film 22 is connected to the N<+>-type impurity layer 18 through a contact hole 23 formed in the interlayer insulating film 22. |
