| 摘要 |
PURPOSE:To prevent the short circuit in polycrystal Si layers of an MOS LSI, in which multilayer polycrystal Si layers are used, by coating an Si nitride film as a protecting film on an element separating oxide film. CONSTITUTION:An oxide film 62 is formed on the surface of a P type Si substrate 61, and an Si nitride film is deposited. Thereafter an Si nitride film 64 is formed by a plasma etching method. Then, a photoresist film 63 is etched away, oxidation is performed, and an element separating oxide film 66 is formed. Thereafter, the Si nitride film 64 is removed. Then, an Si nitride film is again deposited on the surface, and an Si nitride film 67 is formed. After wet etching of the oxide film 62 is performed, oxidation is performed. Then, a first gate electrode 70 is formed. After an N<+> diffusing layer, which is to become the source and drain of a transistor, is formed, a PSG film 73 is deposited. Then, electrode taking out contact holes 74 and 75 are provided by using the photoresist, and Al electrodes 76 and 77 are formed at the part. |
