| 摘要 |
PURPOSE:To prevent the occurrence of bird's beaks and crystal defects, by forming grooves in element isolating regions on the main surface of a single crystal silicon substrate, making polycrystalline silicon films to remain in the grooves flatly, and oxidizing the films completely. CONSTITUTION:Grooves are formed in a single crystal silicon substrate 1. A photo resist film 2 is removed and a surface contaminated layer is removed. Thereafter, a thermal oxide film 6, a nitride film 7, polycrystalline silicon 8 and a PSG film 9 are sequentially formed. The PSG film 9 is patterned, a dummy pattern 10 is formed and a macromolecular film 11 is rotatably applied. The film is etched. The macromolecular resin film is made to remain only in a gap 12 formed between the dummy pattern and the wall of the groove and a narrow groove part 12'. With the film as the mask, etching is carried out so that the film thickness, which is just twice the polycrystalline silicon is etched. The polycrystalline silicon 13 remains flatly in the grooves. The dummy pattern 10 and the macromolecular resin film 12 are removed, and the polycrystalline silicon 13 is oxidized completely. |
