| 摘要 |
PURPOSE:To enhance the storage capacity of a trench capacitor by a method wherein a cell plate inside a trench is extracted and connected to a surface electrode and an intermediate potential is impressed. CONSTITUTION:An insulating layer 3 is formed on a side wall inside a trench 2 in a semiconductor substrate 1; a storage capacitor is formed inside the trench 2 by using a cell plate 4, a dielectric layer 5 and a storage node 6. After the trench 2 has been formed, a p<+> region 1PP is formed in order to prevent a depletion layer from being spread. A source region and a drain region 1A, 1B constitute a FET where word lines 12 as gates become transfer gates. The region 1B is connected electrically to the storage node 6. The cell plate 4 is insulated from the storage node 6, is extracted by piercing the storage node 6, and is connected electrically to an intermediate potential electrode 4A formed on the surface of the substrate. Through this constitution, it is possible to avoid a floating phenomenon of the transfer gates, to increase the capacitance of a capacitor and to enhance a noise-resisting characteristic and the reliability of a cell. |
