| 摘要 |
PURPOSE:To selectively form a flat oxidized film having no birdbeak nor bird head on a semiconductor substrate by oxidizing the substrate together with a polycrystalline silicon layer. CONSTITUTION:A silicon nitride film 2 is formed by a CVD process on the surface of a silicon substrate 1, a pattern is formed, and a polycrystalline silicon 5 is then accumulated on the overall surface by an ordinary or reduced pressure CVD process. Then, the overall surface is oxidized in oxidizing atmosphere, and an oxidized film 51 having a thickness thicker than the necessary oxidized film is obtained as the oxidized film of the field. The film 51 is formed by partly oxidizing polycrystalline silicon+substrate silicon, and the film 52 is formed by oxidizing polycrystalline silicon 5. Subsequently, the film 52 formed on the film 2 is etched, and the exposed film 2 is then removed. Thus, flat and uniform oxidized film 51' is selectively formed on the substrate. |
