| 摘要 |
PROBLEM TO BE SOLVED: To improve resistance with respect to soft error and reliability by increasing the depth of a trench of a solid capacitor for charge storage, formed at a position higher than a substrate upper surface. SOLUTION: A switch transistor is an n-channel type MISFET formed in a region on a p-type silicon substrate 1 isolated with a field oxide film 2, and a gate electrode 4 is a word line on an active region. A wiring electrode 8 is a data line connected to a high-concentration n-type impurity region 5 of a source (or drain) of the switch transistor. Further, a storage electrode 12 of the capacitor for charge storage is provided at the upper ends of the word line and the data line. The storage electrode 12 is connected to a high- concentration n-type impurity region 6 of the MISFET in the memory cell via a silicon plug 10. The storage electrode 12, formed in a trench shape, includes a rectangular-parallelepiped plate electrode 14 via a capacitor insulating film 13 which is between the inner wall of the electrode 12 and the plate electrode 14. |
