| 摘要 |
PURPOSE:To increase an electrode area and amplify the intensity for alpha rays and the like, by forming a side wall part of a trench as a plate after digging it in an Si substrate and using an electrode which is embedded in this trench with an insulating film between the electrode and the side wall as the principal part of a capacitor electrode to accumulate the information. CONSTITUTION:After forming a field oxide film 11 at an Si substrate 10, a trench 17 having a prescribed size is formed. After that, having the same conductivity type as that of the Si substrate, a p<+> type layer 8 has an electric conductivity 1OMEGA-cm or less and is formed at a side wall as well as its base of the trench as a plate 8 and a capacitor insulating film 18 is deposited. A connecting hole 20 for a capacitor electrode which reaches the Si substrate 10 is formed at a designated part of the capacitor insulating film 18 and the poly Si capacitor electrode 10 is deposited at the prescribed part so that it can be connected to the Si substrate 10. As a result, an n<+> type diffusion layer 15 is formed in the Si substrate 10. After that, the first layer insulation film 13 is formed and a gate oxide film 12 is formed and further, the poly Si and Mo silicide or gates of Mo, W, and the like are deposited. Then, As and the like are driven in by an ion implantation process 10 form the n<+> type diffusion layer 15. Further, the second layer insulation film 14 is deposited to form a contact hole 9 towards the n<+> type diffusion layer 15 and a bit line 3 represented by Al is deposited. |
