| 摘要 |
PURPOSE:To suppress short channel effect by forming a concave part in the central part of the surface of a semiconductor substrate surrounded by an electrode separating region, embedding a gate electrode in the concave part through a gate oxide film, and forming source and drain regions on both side thereof by the diffusion from the oxide film including impurities. CONSTITUTION:A P<+> type region 52 is diffused and formed at the peripheral part of a P type Si substrate 51. A thick field oxide film 53 is formed with the region 52 as a base. A CVD oxide film 54 including N type impurities is deposited on the entire surface including the film 53. Then, the concave part is provided in a channel forming region 1 of a transistor from the surface so as to penetrate the substrate 51. By using the remaining film 54, reactive ion etching is performed and the exposed surface is cleaned. Then a gate oxide film 55 is deposited on the bottom surface of the opening, a polycrystal Si layer 56 is embedded therein, and a gate electrode is obtained by patterning. Then heat treatment is performed, while impurities in the film 54 are diffused, and the N<+> source and drain regions 57 are formed on both sides of the electrode of the substrate 51. |
