| 摘要 |
PURPOSE:To obtain a memory device characterized by high degree of integration and excellent withstanding voltage, by providing a capacitor element and a transfer transistor on the same semiconductor substrate, thereby forming a dynamic RAM, and using multilayer films as the insulating films of a capacitor constituting the capacitor element. CONSTITUTION:A thick field oxide film 22 is formed at the peripheral part of a P-type Si substrate 21. A thin thermal oxide film 23 is grown on the surface of the substrate 21 surrounded by the field oxide film 22. With the surface being covered by a photoresist mask, ions are implanted only in a capacitor forming region, and an N<+> type region 24, which is to become one electrode, is formed. An Si3N4 film 25 and an oxide film 26 are laminated on the region 24 through the film 23. The end parts of the films are extended on the film 22. A polycrystalline Si capacitor electrode 27, which is to become another electrode, is provided on the laminated films. The electrode is covered by an inter-layer insulating film 28. Thus a capacitor element is formed. Thereafter, the film 22 on the surface of the substrate, which is contacted with the film 28 is removed. A transfer gate electrode 30, which comprises polycrystalline Si, is provided through a gate oxide film 29. On both sides of the electrode 30, N<+> type source and drain regions 31 and 32 are formed. |
