| 摘要 |
PURPOSE:To correctly form a fine element isolation oxide film, by converting an oxidizable film into an oxide film to increase the volume of the film and to decrease the size of an aperture. CONSTITUTION:A buffer oxide film 22 is formed on the surface of a semiconductor substrate 21. Further, a first anti-oxidation film (e.g. a nitride film) 23, a polycrystalline silicon film 24, a second anti-oxidation film (e.g. a nitride film) 25 and a oxidizable film (a polycrystalline silicon film) 26 are provided thereon subsequently in that order. The oxidizable film 26 is then provided with an aperture 28 and converted into an oxide film 29 to decrease its volume. Using this oxide film 29 as a mask, the second anti-oxidation film 25, the nonsingle-crystal silicon film 24 and the first anti-oxidation film 23 are selectively etched by the anisotropic etching, so that an aperture 30 is provided. The surface of the substrate within the aperture 30 is oxidized to form an element isolation oxide film 31. |
