| 摘要 |
PURPOSE:To enable the advancement in integration by forming plural trench- type capacitors having the same capacitance in a single trench. CONSTITUTION:On a P-type silicon substrate 1, a P-type well region 2 is provided selectively and a memory cell composed of a trench-type capacitor is formed in the region 2. In this trench-type capacitor, charge storing electrodes 4a1 and 4a2 composed of an N<+>-type impurity region which are provided on side walls of the trench and a cell plate electrode 7 buried in a trench 13 through a capacitor insulating film 6 are formed. At that time, capacitors are formed respectively between the N-type impurities 4a1, 4a2 and the electrode 7, resulting in the highly integrated structure in which two capacitors of the same capacitance are made in one trench 13. Thus, an insulator 6 isolates the impurity regions 3a, 3b, 4a1 and 4a2, so that the leakage characteristics is improved and the performance can be enhanced, thereby obtaining a large scale integrated circuit. |
