| 摘要 |
PURPOSE:To microminiaturize a D-RAM memory cell while providing the reliability by storing writing charge at a conductor side, and using a substrate side as a plate, thereby preventing a leakage from a charge storage layer and a software error. CONSTITUTION:Two memory cells made of a MOS transistor 12 and a MOS capacitor 13 are arranged on the element forming region 11 of the surface of an Si substrate 10. The transistor 12 uses a word line 14 mad of second polysilicon as a gate electrode, a drain side as a bit line 15 made of aluminum, and a source side as an electrode 21 connected through a P<+> type diffused layer. The electrode 21 made of first polysilicon forms one electrode of the capacitor 13, the other electrode (plate electrode) is formed of the substrate 10, and the written charge is stored at the first polysilicon side. The electrode 21 is separated by an insulating film 25 and the substrate 10 from adjacent memory cell, and the leakage from the charge storage layer is extremely small. |
