| 摘要 |
PURPOSE:To enhance a capacitor in capacitance and to prevent a dynamic memory cell from deteriorating in inter-trench withstand voltage and a current from leaking out to a substrate by a method wherein a trench-type capacitor is enlarged in area by adding a second capacitor. CONSTITUTION:A memory cell composed of a transistor and a trench-type capacitor is formed at an element forming spot on a P-type silicon substrate 1 demarcated by an element isolating oxide film 5. The trench-type capacitor is equipped with a first capacitor composed of an N-type impurity region 12 which forms the inner wall of a trench 8 extending from an N-type impurity region 11 of the transistor, a first capacitor insulating film 3 formed on all the surface of the inner wall of the trench 8, and a capacitor electrode 2 formed on the first capacitor insulating film 3. Moreover, the trench-type capacitor is equipped with a stacked type second capacitor composed of the capacitor electrode 2, a second capacitor insulating film 13 formed on the capacitor electrode 2 inside the trench 8, and a stacked electrode 4 formed on the second capacitor insulating film 13 as connected to the N-type regions 11 and 12 with a contact 9. |
