| 摘要 |
PURPOSE:To improve the withstanding voltage between polycrystalline silicon elements and the yield rate, by growing a CVD oxide film between the first and second polycrystalline silicon elements and the third polycrystalline silicon element. CONSTITUTION:A field oxide film 102 is selectively formed on a semiconductor substrate 101. Then a first oxide film 103 is formed. A nitride film 104 is grown. Then first polycrystalline silicon 105 is grown, and patterning is performed. The first polycrystalline silicon 105 is thermally oxidized, and a second oxide film 106 is formed. Thereafter the nitride film 104 is etched, and the first oxide film 103 is etched. Second polycrystalline silicon is grown, and patterning is performed. A gate oxide film 107 at an extra part is etched, and a third oxide film 108 is formed by thermal oxidation. A fourth oxide film 110 is grown. After heat treatment, a contact hole 111 is formed by photoetching. Third polycrystalline silicon 112 is formed and patterned. A PSG film 113 is formed, a contact hole is provided and an aluminum wiring layer 114 is formed. |
