| 摘要 |
PURPOSE:To realize further larger capacity by forming the surface of a polycrystalline silicon for a storage electrode in an uneven shape. CONSTITUTION:A word line 14 made of a polycrystalline silicon film is formed on an isolating oxide film 12 formed on a silicon substrate 11 through a gate oxide film 13, and a silicon oxide film 15 is formed thereon. Then, a polycrystalline silicon film 16 for storage electrode is formed by a reduced pressure CVD, etc., arsenic ions (As<+>) are implanted to the entire surface, heat treated to grain grow the silicon film. In this case, arsenic is segregated in the grain boundary. Then, the surface of the film 16 is anisotropically dry etched using HBr gas to form a polycrystalline silicon film 16a having an uneven part. Oxygen ions (O<+>) may be implanted instead of the Ar<+>. |
