| 摘要 |
PURPOSE:To improve a layer insulation withstand-voltage and reform a side surface shape of the first polycrystalline silicon film, by overetching a nitrided film, covering only the side surface part with a thin polycrystal silicon film, and then forming a layer insulation oxide film. CONSTITUTION:Likewise as before, the first polycrystalline silicon film 15 is etched, with patterning-processed photo-sensitive resin 16 serving as mask, and after removing the photo-sensitive resin 16, a nitrided film 14 is overetched, with a patterning-processed first polycrystalline silicon film 15 serving as mask. Then, a thin polycrystalline silicon film 17 is piled all over the surface, and the thin polycrystalline silicon film 17 is etched, by thickness of he film, by the use of an anisotropic etching, so that only the side surface part of the nitrided film 14 is covered with the thin polycrystalline silicon film 17. Next, with the first polycrystalline silicon film 15 serving as mask, the first gate oxide film 13 is removed, and a layer insulation oxide film is formed by thermally oxidizing a semiconductor substrate 11, and then the second polycrystalline silicon film is made to grow into a desired shape patterning. |
