| 摘要 |
PURPOSE:To eliminate a stress which is created in a trench by oxidation by a method wherein a polycrystalline silicon film is built up on a polycrystalline silicon film remaining in the trench selectively in a self-alignment manner and oxidized after the trench is completely filled. CONSTITUTION:A trench is formed selectively in a semiconductor substrate 1 and an insulating film 3 is formed on the substrate 1 surface including the inner wall of the trench 2. Then a polycrystalline silicon film 4 is deposited and the polycrystalline silicon film 4 is made to remain in the trench 2. After that, a polycrystalline silicon film 5 is selectively built up on the polycrystalline silicon film 4 remaining in the trench 2 so as to have its surface higher than the substrate 1 surface. Then the built up polycrystalline silicon film 5 is oxidized to form an oxide film 6. With this constitution, a stress created in the trench 2 by oxidation can be eliminated. |
